diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index f7f45d6d98..34844be67a 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -90,14 +90,15 @@
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
       <Sha>3a25a7f1cc446b60678ed25c9d829420d6321eba</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="9.0.0-beta.23613.3">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="8.0.0-beta.23620.2">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>b6349a217d7e2f6b5c1831702f8beef5c171da3f</Sha>
+      <Sha>84129325171e65373edef24019e1171feeb19cbc</Sha>
       <SourceBuild RepoName="arcade" ManagedOnly="true" />
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.XliffTasks" Version="9.0.0-beta.23613.3">
-      <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>b6349a217d7e2f6b5c1831702f8beef5c171da3f</Sha>
+    <Dependency Name="Microsoft.DotNet.XliffTasks" Version="1.0.0-beta.23475.1" CoherentParentDependency="Microsoft.DotNet.Arcade.Sdk">
+      <Uri>https://github.com/dotnet/xliff-tasks</Uri>
+      <Sha>73f0850939d96131c28cf6ea6ee5aacb4da0083a</Sha>
+      <SourceBuild RepoName="xliff-tasks" ManagedOnly="true" />
     </Dependency>
     <!-- Necessary for source-build. This allows Microsoft.Extensions.ObjectPool and System.Collections.Immutable packages
          to be retrieved from live source-build and their content consumed by packages produced by razor.
diff --git a/eng/common/build.ps1 b/eng/common/build.ps1
index 066044f62f..33a6f2d0e2 100644
--- a/eng/common/build.ps1
+++ b/eng/common/build.ps1
@@ -19,7 +19,6 @@ Param(
   [switch] $pack,
   [switch] $publish,
   [switch] $clean,
-  [switch] $verticalBuild,
   [switch][Alias('bl')]$binaryLog,
   [switch][Alias('nobl')]$excludeCIBinarylog,
   [switch] $ci,
@@ -59,7 +58,6 @@ function Print-Usage() {
   Write-Host "  -sign                   Sign build outputs"
   Write-Host "  -publish                Publish artifacts (e.g. symbols)"
   Write-Host "  -clean                  Clean the solution"
-  Write-Host "  -verticalBuild          Run in 'vertical build' infra mode."
   Write-Host ""
 
   Write-Host "Advanced settings:"
@@ -122,7 +120,6 @@ function Build {
     /p:Deploy=$deploy `
     /p:Test=$test `
     /p:Pack=$pack `
-    /p:ArcadeBuildVertical=$verticalBuild `
     /p:IntegrationTest=$integrationTest `
     /p:PerformanceTest=$performanceTest `
     /p:Sign=$sign `
diff --git a/eng/common/build.sh b/eng/common/build.sh
index 5ce01dd161..50af40cdd2 100755
--- a/eng/common/build.sh
+++ b/eng/common/build.sh
@@ -59,7 +59,6 @@ scriptroot="$( cd -P "$( dirname "$source" )" && pwd )"
 restore=false
 build=false
 source_build=false
-vertical_build=false
 rebuild=false
 test=false
 integration_test=false
@@ -106,7 +105,7 @@ while [[ $# > 0 ]]; do
     -binarylog|-bl)
       binary_log=true
       ;;
-    -excludecibinarylog|-nobl)
+    -excludeCIBinarylog|-nobl)
       exclude_ci_binary_log=true
       ;;
     -pipelineslog|-pl)
@@ -130,12 +129,6 @@ while [[ $# > 0 ]]; do
       restore=true
       pack=true
       ;;
-    -verticalbuild|-vb)
-      build=true
-      vertical_build=true
-      restore=true
-      pack=true
-      ;;
     -test|-t)
       test=true
       ;;
@@ -227,7 +220,6 @@ function Build {
     /p:Restore=$restore \
     /p:Build=$build \
     /p:ArcadeBuildFromSource=$source_build \
-    /p:ArcadeBuildVertical=$vertical_build \
     /p:Rebuild=$rebuild \
     /p:Test=$test \
     /p:Pack=$pack \
diff --git a/eng/common/cross/build-rootfs.sh b/eng/common/cross/build-rootfs.sh
index 4228f202e5..9caf9b021d 100755
--- a/eng/common/cross/build-rootfs.sh
+++ b/eng/common/cross/build-rootfs.sh
@@ -487,7 +487,7 @@ if [[ "$__CodeName" == "alpine" ]]; then
             -X "http://dl-cdn.alpinelinux.org/alpine/$version/main" \
             -X "http://dl-cdn.alpinelinux.org/alpine/$version/community" \
             -U $__ApkSignatureArg --root "$__RootfsDir" --arch "$__AlpineArch" \
-            search 'llvm*-libs' | grep -E '^llvm' | sort | tail -1 | sed 's/-[^-]*//2g')"
+            search 'llvm*-libs' | sort | tail -1 | sed 's/-[^-]*//2g')"
     fi
 
     # install all packages in one go
diff --git a/eng/common/cross/riscv64/tizen/tizen.patch b/eng/common/cross/riscv64/tizen/tizen.patch
deleted file mode 100644
index eb6d1c0747..0000000000
--- a/eng/common/cross/riscv64/tizen/tizen.patch
+++ /dev/null
@@ -1,9 +0,0 @@
-diff -u -r a/usr/lib/libc.so b/usr/lib/libc.so
---- a/usr/lib64/libc.so	2016-12-30 23:00:08.284951863 +0900
-+++ b/usr/lib64/libc.so	2016-12-30 23:00:32.140951815 +0900
-@@ -2,4 +2,4 @@
-    Use the shared library, but some functions are only in
-    the static library, so try that secondarily.  */
- OUTPUT_FORMAT(elf64-littleriscv)
--GROUP ( /lib64/libc.so.6 /usr/lib64/libc_nonshared.a  AS_NEEDED ( /lib64/ld-linux-riscv64-lp64d.so.1 ) )
-+GROUP ( libc.so.6 libc_nonshared.a  AS_NEEDED ( ld-linux-riscv64-lp64d.so.1 ) )
diff --git a/eng/common/cross/tizen-build-rootfs.sh b/eng/common/cross/tizen-build-rootfs.sh
index ba31c93285..ac84173d44 100644
--- a/eng/common/cross/tizen-build-rootfs.sh
+++ b/eng/common/cross/tizen-build-rootfs.sh
@@ -22,10 +22,6 @@ case "$ARCH" in
         TIZEN_ARCH="x86_64"
         LINK_ARCH="x86"
         ;;
-    riscv64)
-        TIZEN_ARCH="riscv64"
-        LINK_ARCH="riscv"
-        ;;
     *)
         echo "Unsupported architecture for tizen: $ARCH"
         exit 1
@@ -62,21 +58,4 @@ rm -rf $TIZEN_TMP_DIR
 echo ">>Start configuring Tizen rootfs"
 ln -sfn asm-${LINK_ARCH} ./usr/include/asm
 patch -p1 < $__TIZEN_CROSSDIR/tizen.patch
-if [[ "$TIZEN_ARCH" == "riscv64" ]]; then
-    echo "Fixing broken symlinks in $PWD"
-    rm ./usr/lib64/libresolv.so
-    ln -s ../../lib64/libresolv.so.2 ./usr/lib64/libresolv.so
-    rm ./usr/lib64/libpthread.so
-    ln -s ../../lib64/libpthread.so.0 ./usr/lib64/libpthread.so
-    rm ./usr/lib64/libdl.so
-    ln -s ../../lib64/libdl.so.2 ./usr/lib64/libdl.so
-    rm ./usr/lib64/libutil.so
-    ln -s ../../lib64/libutil.so.1 ./usr/lib64/libutil.so
-    rm ./usr/lib64/libm.so
-    ln -s ../../lib64/libm.so.6 ./usr/lib64/libm.so
-    rm ./usr/lib64/librt.so
-    ln -s ../../lib64/librt.so.1 ./usr/lib64/librt.so
-    rm ./lib/ld-linux-riscv64-lp64d.so.1
-    ln -s ../lib64/ld-linux-riscv64-lp64d.so.1 ./lib/ld-linux-riscv64-lp64d.so.1
-fi
 echo "<<Finish configuring Tizen rootfs"
diff --git a/eng/common/cross/tizen-fetch.sh b/eng/common/cross/tizen-fetch.sh
index c15c506695..c18de68d3e 100644
--- a/eng/common/cross/tizen-fetch.sh
+++ b/eng/common/cross/tizen-fetch.sh
@@ -156,28 +156,17 @@ fetch_tizen_pkgs()
     done
 }
 
-if [ "$TIZEN_ARCH" == "riscv64" ]; then
-    BASE="Tizen-Base-RISCV"
-    UNIFIED="Tizen-Unified-RISCV"
-else
-    BASE="Tizen-Base"
-    UNIFIED="Tizen-Unified"
-fi
-
 Inform "Initialize ${TIZEN_ARCH} base"
-fetch_tizen_pkgs_init standard $BASE
+fetch_tizen_pkgs_init standard Tizen-Base
 Inform "fetch common packages"
 fetch_tizen_pkgs ${TIZEN_ARCH} gcc gcc-devel-static glibc glibc-devel libicu libicu-devel libatomic linux-glibc-devel keyutils keyutils-devel libkeyutils
 Inform "fetch coreclr packages"
-fetch_tizen_pkgs ${TIZEN_ARCH} libgcc libstdc++ libstdc++-devel libunwind libunwind-devel lttng-ust-devel lttng-ust userspace-rcu-devel userspace-rcu
-if [ "$TIZEN_ARCH" != "riscv64" ]; then
-    fetch_tizen_pkgs ${TIZEN_ARCH} lldb lldb-devel
-fi
+fetch_tizen_pkgs ${TIZEN_ARCH} lldb lldb-devel libgcc libstdc++ libstdc++-devel libunwind libunwind-devel lttng-ust-devel lttng-ust userspace-rcu-devel userspace-rcu
 Inform "fetch corefx packages"
 fetch_tizen_pkgs ${TIZEN_ARCH} libcom_err libcom_err-devel zlib zlib-devel libopenssl11 libopenssl1.1-devel krb5 krb5-devel
 
 Inform "Initialize standard unified"
-fetch_tizen_pkgs_init standard $UNIFIED
+fetch_tizen_pkgs_init standard Tizen-Unified
 Inform "fetch corefx packages"
 fetch_tizen_pkgs ${TIZEN_ARCH} gssdp gssdp-devel tizen-release
 
diff --git a/eng/common/cross/toolchain.cmake b/eng/common/cross/toolchain.cmake
index 3762640fdc..0998e875e5 100644
--- a/eng/common/cross/toolchain.cmake
+++ b/eng/common/cross/toolchain.cmake
@@ -80,9 +80,6 @@ elseif(TARGET_ARCH_NAME STREQUAL "riscv64")
     set(TOOLCHAIN "riscv64-alpine-linux-musl")
   else()
     set(TOOLCHAIN "riscv64-linux-gnu")
-    if(TIZEN)
-      set(TIZEN_TOOLCHAIN "riscv64-tizen-linux-gnu/13.1.0")
-    endif()
   endif()
 elseif(TARGET_ARCH_NAME STREQUAL "s390x")
   set(CMAKE_SYSTEM_PROCESSOR s390x)
@@ -147,10 +144,6 @@ if(TIZEN)
     include_directories(SYSTEM ${CROSS_ROOTFS}/usr/lib64/gcc/${TIZEN_TOOLCHAIN}/include/c++/)
     include_directories(SYSTEM ${CROSS_ROOTFS}/usr/lib64/gcc/${TIZEN_TOOLCHAIN}/include/c++/x86_64-tizen-linux-gnu)
   endif()
-  if(TARGET_ARCH_NAME STREQUAL "riscv64")
-    include_directories(SYSTEM ${CROSS_ROOTFS}/usr/lib64/gcc/${TIZEN_TOOLCHAIN}/include/c++/)
-    include_directories(SYSTEM ${CROSS_ROOTFS}/usr/lib64/gcc/${TIZEN_TOOLCHAIN}/include/c++/riscv64-tizen-linux-gnu)
-  endif()
 endif()
 
 if(ANDROID)
@@ -277,7 +270,7 @@ if(TARGET_ARCH_NAME MATCHES "^(arm|armel)$")
     add_toolchain_linker_flag("-L${CROSS_ROOTFS}/usr/lib")
     add_toolchain_linker_flag("-L${CROSS_ROOTFS}/usr/lib/gcc/${TIZEN_TOOLCHAIN}")
   endif()
-elseif(TARGET_ARCH_NAME MATCHES "^(arm64|x64|riscv64)$")
+elseif(TARGET_ARCH_NAME MATCHES "^(arm64|x64)$")
   if(TIZEN)
     add_toolchain_linker_flag("-B${CROSS_ROOTFS}/usr/lib64/gcc/${TIZEN_TOOLCHAIN}")
     add_toolchain_linker_flag("-L${CROSS_ROOTFS}/lib64")
@@ -288,8 +281,6 @@ elseif(TARGET_ARCH_NAME MATCHES "^(arm64|x64|riscv64)$")
     add_toolchain_linker_flag("-Wl,--rpath-link=${CROSS_ROOTFS}/usr/lib64")
     add_toolchain_linker_flag("-Wl,--rpath-link=${CROSS_ROOTFS}/usr/lib64/gcc/${TIZEN_TOOLCHAIN}")
   endif()
-elseif(TARGET_ARCH_NAME STREQUAL "s390x")
-  add_toolchain_linker_flag("--target=${TOOLCHAIN}")
 elseif(TARGET_ARCH_NAME STREQUAL "x86")
   if(EXISTS ${CROSS_ROOTFS}/usr/lib/gcc/i586-alpine-linux-musl)
     add_toolchain_linker_flag("--target=${TOOLCHAIN}")
@@ -337,8 +328,6 @@ if(TARGET_ARCH_NAME MATCHES "^(arm|armel)$")
   if(TARGET_ARCH_NAME STREQUAL "armel")
     add_compile_options(-mfloat-abi=softfp)
   endif()
-elseif(TARGET_ARCH_NAME STREQUAL "s390x")
-  add_compile_options("--target=${TOOLCHAIN}")
 elseif(TARGET_ARCH_NAME STREQUAL "x86")
   if(EXISTS ${CROSS_ROOTFS}/usr/lib/gcc/i586-alpine-linux-musl)
     add_compile_options(--target=${TOOLCHAIN})
diff --git a/eng/common/post-build/check-channel-consistency.ps1 b/eng/common/post-build/check-channel-consistency.ps1
index 1728f035a9..63f3464c98 100644
--- a/eng/common/post-build/check-channel-consistency.ps1
+++ b/eng/common/post-build/check-channel-consistency.ps1
@@ -7,7 +7,7 @@ try {
   . $PSScriptRoot\post-build-utils.ps1
 
   if ($PromoteToChannels -eq "") {
-    Write-PipelineTaskError -Type 'warning' -Message "This build won't publish assets as it's not configured to any Maestro channel. If that wasn't intended use Darc to configure a default channel using add-default-channel for this branch or to promote it to a channel using add-build-to-channel. See https://github.com/dotnet/arcade/blob/main/Documentation/Darc.md#assigning-an-individual-build-to-a-channel for more info."
+    Write-PipelineTaskError -Type 'warning' -Message "This build won't publish assets as it's not configured to any Maestro channel. If that wasn't intended use Darc to configure a default channel using add-default-channel for this branch or to promote it to a channel using add-build-to-channel. See https://github.com/dotnet/arcade/blob/master/Documentation/Darc.md#assigning-an-individual-build-to-a-channel for more info."
     ExitWithExitCode 0
   }
 
diff --git a/eng/common/post-build/redact-logs.ps1 b/eng/common/post-build/redact-logs.ps1
deleted file mode 100644
index 82d91f6fd0..0000000000
--- a/eng/common/post-build/redact-logs.ps1
+++ /dev/null
@@ -1,81 +0,0 @@
-[CmdletBinding(PositionalBinding=$False)]
-param(
-  [Parameter(Mandatory=$true, Position=0)][string] $InputPath,
-  [Parameter(Mandatory=$true)][string] $BinlogToolVersion,
-  [Parameter(Mandatory=$false)][string] $DotnetPath,
-  [Parameter(Mandatory=$false)][string] $PackageFeed = 'https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json',
-  # File with strings to redact - separated by newlines.
-  #  For comments start the line with '# ' - such lines are ignored 
-  [Parameter(Mandatory=$false)][string] $TokensFilePath,
-  [Parameter(ValueFromRemainingArguments=$true)][String[]]$TokensToRedact
-)
-
-try {
-  . $PSScriptRoot\post-build-utils.ps1
-
-  $packageName = 'binlogtool'
-
-  $dotnet = $DotnetPath
-
-  if (!$dotnet) {
-    $dotnetRoot = InitializeDotNetCli -install:$true
-    $dotnet = "$dotnetRoot\dotnet.exe"
-  }
-  
-  $toolList = & "$dotnet" tool list -g
-
-  if ($toolList -like "*$packageName*") {
-    & "$dotnet" tool uninstall $packageName -g
-  }
-
-  $toolPath  = "$PSScriptRoot\..\..\..\.tools"
-  $verbosity = 'minimal'
-  
-  New-Item -ItemType Directory -Force -Path $toolPath
-  
-  Push-Location -Path $toolPath
-
-  try {
-    Write-Host "Installing Binlog redactor CLI..."
-    Write-Host "'$dotnet' new tool-manifest"
-    & "$dotnet" new tool-manifest
-    Write-Host "'$dotnet' tool install $packageName --local --add-source '$PackageFeed' -v $verbosity --version $BinlogToolVersion"
-    & "$dotnet" tool install $packageName --local --add-source "$PackageFeed" -v $verbosity --version $BinlogToolVersion
-
-    if (Test-Path $TokensFilePath) {
-        Write-Host "Adding additional sensitive data for redaction from file: " $TokensFilePath
-        $TokensToRedact += Get-Content -Path $TokensFilePath | Foreach {$_.Trim()} | Where { $_ -notmatch "^# " }
-    }
-
-    $optionalParams = [System.Collections.ArrayList]::new()
-  
-    Foreach ($p in $TokensToRedact)
-    {
-      if($p -match '^\$\(.*\)$')
-      {
-        Write-Host ("Ignoring token {0} as it is probably unexpanded AzDO variable"  -f $p)
-      }          
-      elseif($p)
-      {
-        $optionalParams.Add("-p:" + $p) | Out-Null
-      }
-    }
-
-    & $dotnet binlogtool redact --input:$InputPath --recurse --in-place `
-      @optionalParams
-
-    if ($LastExitCode -ne 0) {
-      Write-PipelineTelemetryError -Category 'Redactor' -Type 'warning' -Message "Problems using Redactor tool (exit code: $LastExitCode). But ignoring them now."
-    }
-  }
-  finally {
-    Pop-Location
-  }
-
-  Write-Host 'done.'
-} 
-catch {
-  Write-Host $_
-  Write-PipelineTelemetryError -Category 'Redactor' -Message "There was an error while trying to redact logs. Error: $_"
-  ExitWithExitCode 1
-}
diff --git a/eng/common/templates/job/job.yml b/eng/common/templates/job/job.yml
index 0b01531357..e24ca2f46f 100644
--- a/eng/common/templates/job/job.yml
+++ b/eng/common/templates/job/job.yml
@@ -136,7 +136,7 @@ jobs:
         condition: and(succeeded(), in(variables['_SignType'], 'real', 'test'), eq(variables['Agent.Os'], 'Windows_NT'))
 
   - ${{ if and(eq(parameters.runAsPublic, 'false'), eq(variables['System.TeamProject'], 'internal')) }}:
-    - task: NuGetAuthenticate@0
+    - task: NuGetAuthenticate@1
 
   - ${{ if and(ne(parameters.artifacts.download, 'false'), ne(parameters.artifacts.download, '')) }}:
     - task: DownloadPipelineArtifact@2
@@ -154,7 +154,7 @@ jobs:
       displayName: RichCodeNav Upload
       inputs:
         languages: ${{ coalesce(parameters.richCodeNavigationLanguage, 'csharp') }}
-        environment: ${{ coalesce(parameters.richCodeNavigationEnvironment, 'internal') }}
+        environment: ${{ coalesce(parameters.richCodeNavigationEnvironment, 'production') }}
         richNavLogOutputDirectory: $(Build.SourcesDirectory)/artifacts/bin
         uploadRichNavArtifacts: ${{ coalesce(parameters.richCodeNavigationUploadArtifacts, false) }}
       continueOnError: true
diff --git a/eng/common/templates/job/publish-build-assets.yml b/eng/common/templates/job/publish-build-assets.yml
index 3b25fd9792..fa5446c093 100644
--- a/eng/common/templates/job/publish-build-assets.yml
+++ b/eng/common/templates/job/publish-build-assets.yml
@@ -48,8 +48,8 @@ jobs:
     - group: AzureDevOps-Artifact-Feeds-Pats
     - name: runCodesignValidationInjection
       value: false
-    # unconditional - needed for logs publishing (redactor tool version)
-    - template: /eng/common/templates/post-build/common-variables.yml
+    - ${{ if eq(parameters.publishAssetsImmediately, 'true') }}:
+      - template: /eng/common/templates/post-build/common-variables.yml
 
   pool:
     # We don't use the collection uri here because it might vary (.visualstudio.com vs. dev.azure.com)
@@ -72,7 +72,7 @@ jobs:
       condition: ${{ parameters.condition }}
       continueOnError: ${{ parameters.continueOnError }}
     
-    - task: NuGetAuthenticate@0
+    - task: NuGetAuthenticate@1
 
     - task: PowerShell@2
       displayName: Publish Build Assets
diff --git a/eng/common/templates/job/source-index-stage1.yml b/eng/common/templates/job/source-index-stage1.yml
index 7952336626..b98202aa02 100644
--- a/eng/common/templates/job/source-index-stage1.yml
+++ b/eng/common/templates/job/source-index-stage1.yml
@@ -1,6 +1,6 @@
 parameters:
   runAsPublic: false
-  sourceIndexPackageVersion: 1.0.1-20231213.4
+  sourceIndexPackageVersion: 1.0.1-20230228.2
   sourceIndexPackageSource: https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json
   sourceIndexBuildCommand: powershell -NoLogo -NoProfile -ExecutionPolicy Bypass -Command "eng/common/build.ps1 -restore -build -binarylog -ci"
   preSteps: []
@@ -30,20 +30,20 @@ jobs:
     pool:
       ${{ if eq(variables['System.TeamProject'], 'public') }}:
         name: $(DncEngPublicBuildPool)
-        demands: ImageOverride -equals windows.vs2022.amd64.open
+        demands: ImageOverride -equals windows.vs2019.amd64.open
       ${{ if eq(variables['System.TeamProject'], 'internal') }}:
         name: $(DncEngInternalBuildPool)
-        demands: ImageOverride -equals windows.vs2022.amd64
+        demands: ImageOverride -equals windows.vs2019.amd64
 
   steps:
   - ${{ each preStep in parameters.preSteps }}:
     - ${{ preStep }}
 
   - task: UseDotNet@2
-    displayName: Use .NET 8 SDK
+    displayName: Use .NET Core SDK 6
     inputs:
       packageType: sdk
-      version: 8.0.x
+      version: 6.0.x
       installationPath: $(Agent.TempDirectory)/dotnet
       workingDirectory: $(Agent.TempDirectory)
 
diff --git a/eng/common/templates/post-build/common-variables.yml b/eng/common/templates/post-build/common-variables.yml
index 4ef7bd271f..173914f236 100644
--- a/eng/common/templates/post-build/common-variables.yml
+++ b/eng/common/templates/post-build/common-variables.yml
@@ -17,8 +17,6 @@ variables:
     value: 3.0.0
   - name: SymbolToolVersion
     value: 1.0.1
-  - name: BinlogToolVersion
-    value: 1.0.8
 
   - name: runCodesignValidationInjection
     value: false
diff --git a/eng/common/templates/post-build/post-build.yml b/eng/common/templates/post-build/post-build.yml
index d64236b28c..3f74abf7ce 100644
--- a/eng/common/templates/post-build/post-build.yml
+++ b/eng/common/templates/post-build/post-build.yml
@@ -169,7 +169,7 @@ stages:
         # This is necessary whenever we want to publish/restore to an AzDO private feed
         # Since sdk-task.ps1 tries to restore packages we need to do this authentication here
         # otherwise it'll complain about accessing a private feed.
-        - task: NuGetAuthenticate@0
+        - task: NuGetAuthenticate@1
           displayName: 'Authenticate to AzDO Feeds'
 
         # Signing validation will optionally work with the buildmanifest file which is downloaded from
@@ -187,7 +187,6 @@ stages:
           parameters:
             StageLabel: 'Validation'
             JobLabel: 'Signing'
-            BinlogToolVersion: $(BinlogToolVersion)
 
     - job:
       displayName: SourceLink Validation
@@ -267,7 +266,7 @@ stages:
             BARBuildId: ${{ parameters.BARBuildId }}
             PromoteToChannelIds: ${{ parameters.PromoteToChannelIds }}
 
-        - task: NuGetAuthenticate@0
+        - task: NuGetAuthenticate@1
 
         - task: PowerShell@2
           displayName: Publish Using Darc
diff --git a/eng/common/templates/steps/publish-logs.yml b/eng/common/templates/steps/publish-logs.yml
index dadf1c464c..88f238f36b 100644
--- a/eng/common/templates/steps/publish-logs.yml
+++ b/eng/common/templates/steps/publish-logs.yml
@@ -1,9 +1,6 @@
 parameters:
   StageLabel: ''
   JobLabel: ''
-  CustomSensitiveDataList: ''
-  # A default - in case value from eng/common/templates/post-build/common-variables.yml is not passed
-  BinlogToolVersion: '1.0.8'
 
 steps:
 - task: Powershell@2
@@ -15,30 +12,7 @@ steps:
       Move-Item -Path $(Build.SourcesDirectory)/artifacts/log/Debug/* $(Build.SourcesDirectory)/PostBuildLogs/${{parameters.StageLabel}}/${{parameters.JobLabel}}/
   continueOnError: true
   condition: always()
-    
-- task: PowerShell@2
-  displayName: Redact Logs
-  inputs:
-    filePath: $(Build.SourcesDirectory)/eng/common/post-build/redact-logs.ps1
-    # For now this needs to have explicit list of all sensitive data. Taken from eng/publishing/v3/publish.yml
-    # Sensitive data can as well be added to $(Build.SourcesDirectory)/eng/BinlogSecretsRedactionFile.txt'
-    #  If the file exists - sensitive data for redaction will be sourced from it
-    #  (single entry per line, lines starting with '# ' are considered comments and skipped)
-    arguments: -InputPath '$(Build.SourcesDirectory)/PostBuildLogs' 
-      -BinlogToolVersion ${{parameters.BinlogToolVersion}}
-      -TokensFilePath '$(Build.SourcesDirectory)/eng/BinlogSecretsRedactionFile.txt'
-      '$(publishing-dnceng-devdiv-code-r-build-re)'
-      '$(MaestroAccessToken)'
-      '$(dn-bot-all-orgs-artifact-feeds-rw)'
-      '$(akams-client-id)'
-      '$(akams-client-secret)'
-      '$(microsoft-symbol-server-pat)'
-      '$(symweb-symbol-server-pat)'
-      '$(dn-bot-all-orgs-build-rw-code-rw)'
-      ${{parameters.CustomSensitiveDataList}}
-  continueOnError: true
-  condition: always()
-      
+
 - task: PublishBuildArtifacts@1
   displayName: Publish Logs
   inputs:
diff --git a/eng/common/tools.ps1 b/eng/common/tools.ps1
index 540393a663..fdd0cbb91f 100644
--- a/eng/common/tools.ps1
+++ b/eng/common/tools.ps1
@@ -158,13 +158,18 @@ function InitializeDotNetCli([bool]$install, [bool]$createSdkLocationFile) {
   $env:DOTNET_MULTILEVEL_LOOKUP=0
 
   # Disable first run since we do not need all ASP.NET packages restored.
-  $env:DOTNET_NOLOGO=1
+  $env:DOTNET_SKIP_FIRST_TIME_EXPERIENCE=1
 
   # Disable telemetry on CI.
   if ($ci) {
     $env:DOTNET_CLI_TELEMETRY_OPTOUT=1
   }
 
+  # Source Build uses DotNetCoreSdkDir variable
+  if ($env:DotNetCoreSdkDir -ne $null) {
+    $env:DOTNET_INSTALL_DIR = $env:DotNetCoreSdkDir
+  }
+
   # Find the first path on %PATH% that contains the dotnet.exe
   if ($useInstalledDotNetCli -and (-not $globalJsonHasRuntimes) -and ($env:DOTNET_INSTALL_DIR -eq $null)) {
     $dotnetExecutable = GetExecutableFileName 'dotnet'
@@ -223,7 +228,7 @@ function InitializeDotNetCli([bool]$install, [bool]$createSdkLocationFile) {
   Write-PipelinePrependPath -Path $dotnetRoot
 
   Write-PipelineSetVariable -Name 'DOTNET_MULTILEVEL_LOOKUP' -Value '0'
-  Write-PipelineSetVariable -Name 'DOTNET_NOLOGO' -Value '1'
+  Write-PipelineSetVariable -Name 'DOTNET_SKIP_FIRST_TIME_EXPERIENCE' -Value '1'
 
   return $global:_DotNetInstallDir = $dotnetRoot
 }
@@ -822,8 +827,7 @@ function MSBuild-Core() {
     }
   }
 
-  # Be sure quote the path in case there are spaces in the dotnet installation location.
-  $env:ARCADE_BUILD_TOOL_COMMAND = "`"$($buildTool.Path)`" $cmdArgs"
+  $env:ARCADE_BUILD_TOOL_COMMAND = "$($buildTool.Path) $cmdArgs"
 
   $exitCode = Exec-Process $buildTool.Path $cmdArgs
 
diff --git a/eng/common/tools.sh b/eng/common/tools.sh
index 9e979ac16f..e8d4789433 100755
--- a/eng/common/tools.sh
+++ b/eng/common/tools.sh
@@ -112,7 +112,7 @@ function InitializeDotNetCli {
   export DOTNET_MULTILEVEL_LOOKUP=0
 
   # Disable first run since we want to control all package sources
-  export DOTNET_NOLOGO=1
+  export DOTNET_SKIP_FIRST_TIME_EXPERIENCE=1
 
   # Disable telemetry on CI
   if [[ $ci == true ]]; then
@@ -123,6 +123,11 @@ function InitializeDotNetCli {
   # so it doesn't output warnings to the console.
   export LTTNG_HOME="$HOME"
 
+  # Source Build uses DotNetCoreSdkDir variable
+  if [[ -n "${DotNetCoreSdkDir:-}" ]]; then
+    export DOTNET_INSTALL_DIR="$DotNetCoreSdkDir"
+  fi
+
   # Find the first path on $PATH that contains the dotnet.exe
   if [[ "$use_installed_dotnet_cli" == true && $global_json_has_runtimes == false && -z "${DOTNET_INSTALL_DIR:-}" ]]; then
     local dotnet_path=`command -v dotnet`
@@ -160,7 +165,7 @@ function InitializeDotNetCli {
   Write-PipelinePrependPath -path "$dotnet_root"
 
   Write-PipelineSetVariable -name "DOTNET_MULTILEVEL_LOOKUP" -value "0"
-  Write-PipelineSetVariable -name "DOTNET_NOLOGO" -value "1"
+  Write-PipelineSetVariable -name "DOTNET_SKIP_FIRST_TIME_EXPERIENCE" -value "1"
 
   # return value
   _InitializeDotNetCli="$dotnet_root"
@@ -305,7 +310,7 @@ function GetDotNetInstallScript {
       curl "$install_script_url" -sSL --retry 10 --create-dirs -o "$install_script" || {
         if command -v openssl &> /dev/null; then
           echo "Curl failed; dumping some information about dotnet.microsoft.com for later investigation"
-          echo | openssl s_client -showcerts -servername dotnet.microsoft.com  -connect dotnet.microsoft.com:443 || true
+          echo | openssl s_client -showcerts -servername dotnet.microsoft.com  -connect dotnet.microsoft.com:443
         fi
         echo "Will now retry the same URL with verbose logging."
         with_retries curl "$install_script_url" -sSL --verbose --retry 10 --create-dirs -o "$install_script" || {
@@ -336,12 +341,7 @@ function InitializeBuildTool {
   # return values
   _InitializeBuildTool="$_InitializeDotNetCli/dotnet"
   _InitializeBuildToolCommand="msbuild"
-  # use override if it exists - commonly set by source-build
-  if [[ "${_OverrideArcadeInitializeBuildToolFramework:-x}" == "x" ]]; then
-    _InitializeBuildToolFramework="net8.0"
-  else
-    _InitializeBuildToolFramework="${_OverrideArcadeInitializeBuildToolFramework}"
-  fi
+  _InitializeBuildToolFramework="net8.0"
 }
 
 # Set RestoreNoCache as a workaround for https://github.com/NuGet/Home/issues/3116
diff --git a/eng/config/PublishData.json b/eng/config/PublishData.json
index 051b9f4e83..d9b467aa0e 100644
--- a/eng/config/PublishData.json
+++ b/eng/config/PublishData.json
@@ -7,8 +7,8 @@
       ],
       "vsBranch": "main",
       "vsMajorVersion": 17,
-      "insertionCreateDraftPR": false,
-      "insertionTitlePrefix": "[17.9P3]"
+      "insertionCreateDraftPR": true,
+      "insertionTitlePrefix": "[17.10 Validation]"
     },
     "release/dev17.5": {
       "nugetKind": [
@@ -51,9 +51,9 @@
         "Shipping",
         "NonShipping"
       ],
-      "vsBranch": "rel/d17.9",
+      "vsBranch": "main",
       "vsMajorVersion": 17,
-      "insertionTitlePrefix": "[17.9P2]"
+      "insertionTitlePrefix": "[17.9]"
     }
   }
 }
diff --git a/global.json b/global.json
index 44a1c49284..589ada96f8 100644
--- a/global.json
+++ b/global.json
@@ -21,6 +21,6 @@
     "rollForward": "latestPatch"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "9.0.0-beta.23613.3"
+    "Microsoft.DotNet.Arcade.Sdk": "8.0.0-beta.23620.2"
   }
 }
diff --git a/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs b/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs
index 7e44e84799..0559abaae4 100644
--- a/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs
+++ b/src/Razor/benchmarks/Microsoft.AspNetCore.Razor.Microbenchmarks/LanguageServer/RazorLanguageServerBenchmarkBase.cs
@@ -64,7 +64,7 @@ public class RazorLanguageServerBenchmarkBase : ProjectSnapshotManagerBenchmarkB
         var projectSnapshotManager = CreateProjectSnapshotManager();
         projectSnapshotManager.ProjectAdded(hostProject);
         var tagHelpers = CommonResources.LegacyTagHelpers;
-        var projectWorkspaceState = new ProjectWorkspaceState(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.CSharp11);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.CSharp11);
         projectSnapshotManager.ProjectWorkspaceStateChanged(hostProject.Key, projectWorkspaceState);
         projectSnapshotManager.DocumentAdded(hostProject.Key, hostDocument, textLoader);
         var projectSnapshot = projectSnapshotManager.GetLoadedProject(hostProject.Key);
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ExternalAccess.RoslynWorkspace/RazorProjectInfoSerializer.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ExternalAccess.RoslynWorkspace/RazorProjectInfoSerializer.cs
index 67ed7be795..4d793a35b6 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ExternalAccess.RoslynWorkspace/RazorProjectInfoSerializer.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ExternalAccess.RoslynWorkspace/RazorProjectInfoSerializer.cs
@@ -85,7 +85,7 @@ internal static class RazorProjectInfoSerializer
         var resolver = new CompilationTagHelperResolver(NoOpTelemetryReporter.Instance);
         var tagHelpers = await resolver.GetTagHelpersAsync(project, engine, cancellationToken).ConfigureAwait(false);
 
-        var projectWorkspaceState = new ProjectWorkspaceState(tagHelpers, csharpLanguageVersion);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers, csharpLanguageVersion);
 
         var configurationFilePath = Path.Combine(intermediateOutputPath, configurationFileName);
 
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/ProjectWorkspaceState.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/ProjectWorkspaceState.cs
index 042f9c9b84..b4c2c9548f 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/ProjectWorkspaceState.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/ProjectWorkspaceState.cs
@@ -17,7 +17,7 @@ internal sealed class ProjectWorkspaceState : IEquatable<ProjectWorkspaceState>
     public ImmutableArray<TagHelperDescriptor> TagHelpers { get; }
     public LanguageVersion CSharpLanguageVersion { get; }
 
-    public ProjectWorkspaceState(
+    private ProjectWorkspaceState(
         ImmutableArray<TagHelperDescriptor> tagHelpers,
         LanguageVersion csharpLanguageVersion)
     {
@@ -25,6 +25,18 @@ internal sealed class ProjectWorkspaceState : IEquatable<ProjectWorkspaceState>
         CSharpLanguageVersion = csharpLanguageVersion;
     }
 
+    public static ProjectWorkspaceState Create(
+        ImmutableArray<TagHelperDescriptor> tagHelpers,
+        LanguageVersion csharpLanguageVersion = LanguageVersion.Default)
+        => tagHelpers.IsEmpty && csharpLanguageVersion == LanguageVersion.Default
+            ? Default
+            : new(tagHelpers, csharpLanguageVersion);
+
+    public static ProjectWorkspaceState Create(LanguageVersion csharpLanguageVersion)
+        => csharpLanguageVersion == LanguageVersion.Default
+            ? Default
+            : new(ImmutableArray<TagHelperDescriptor>.Empty, csharpLanguageVersion);
+
     public override bool Equals(object? obj)
         => obj is ProjectWorkspaceState other && Equals(other);
 
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/RazorProjectInfo.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/RazorProjectInfo.cs
index 7abbcc4469..b4072089d0 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/RazorProjectInfo.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/ProjectSystem/RazorProjectInfo.cs
@@ -21,19 +21,19 @@ internal sealed class RazorProjectInfo
 
     public string SerializedFilePath { get; }
     public string FilePath { get; }
-    public RazorConfiguration? Configuration { get; }
+    public RazorConfiguration Configuration { get; }
     public string? RootNamespace { get; }
     public string DisplayName { get; }
-    public ProjectWorkspaceState? ProjectWorkspaceState { get; }
+    public ProjectWorkspaceState ProjectWorkspaceState { get; }
     public ImmutableArray<DocumentSnapshotHandle> Documents { get; }
 
     public RazorProjectInfo(
         string serializedFilePath,
         string filePath,
-        RazorConfiguration? configuration,
+        RazorConfiguration configuration,
         string? rootNamespace,
         string displayName,
-        ProjectWorkspaceState? projectWorkspaceState,
+        ProjectWorkspaceState projectWorkspaceState,
         ImmutableArray<DocumentSnapshotHandle> documents)
     {
         SerializedFilePath = serializedFilePath;
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectReaders.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectReaders.cs
index 0e5f30e482..1b244a16ea 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectReaders.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectReaders.cs
@@ -79,7 +79,7 @@ internal static partial class ObjectReaders
     public static ProjectSnapshotHandle ReadProjectSnapshotHandleFromProperties(JsonDataReader reader)
     {
         var projectIdString = reader.ReadNonNullString(nameof(ProjectSnapshotHandle.ProjectId));
-        var configuration = reader.ReadObjectOrNull(nameof(ProjectSnapshotHandle.Configuration), ReadConfigurationFromProperties);
+        var configuration = reader.ReadObjectOrNull(nameof(ProjectSnapshotHandle.Configuration), ReadConfigurationFromProperties) ?? RazorConfiguration.Default;
         var rootNamespace = reader.ReadStringOrNull(nameof(ProjectSnapshotHandle.RootNamespace));
 
         var projectId = ProjectId.CreateFromSerialized(Guid.Parse(projectIdString));
@@ -101,7 +101,7 @@ internal static partial class ObjectReaders
         var tagHelpers = reader.ReadImmutableArrayOrEmpty(nameof(ProjectWorkspaceState.TagHelpers), static r => ReadTagHelper(r, useCache: true));
         var csharpLanguageVersion = (LanguageVersion)reader.ReadInt32OrZero(nameof(ProjectWorkspaceState.CSharpLanguageVersion));
 
-        return new ProjectWorkspaceState(tagHelpers, csharpLanguageVersion);
+        return ProjectWorkspaceState.Create(tagHelpers, csharpLanguageVersion);
     }
 
     public static TagHelperDescriptor ReadTagHelper(JsonDataReader reader, bool useCache)
@@ -342,8 +342,8 @@ internal static partial class ObjectReaders
 
         var serializedFilePath = reader.ReadNonNullString(nameof(RazorProjectInfo.SerializedFilePath));
         var filePath = reader.ReadNonNullString(nameof(RazorProjectInfo.FilePath));
-        var configuration = reader.ReadObject(nameof(RazorProjectInfo.Configuration), ReadConfigurationFromProperties);
-        var projectWorkspaceState = reader.ReadObject(nameof(RazorProjectInfo.ProjectWorkspaceState), ReadProjectWorkspaceStateFromProperties);
+        var configuration = reader.ReadObject(nameof(RazorProjectInfo.Configuration), ReadConfigurationFromProperties) ?? RazorConfiguration.Default;
+        var projectWorkspaceState = reader.ReadObject(nameof(RazorProjectInfo.ProjectWorkspaceState), ReadProjectWorkspaceStateFromProperties) ?? ProjectWorkspaceState.Default;
         var rootNamespace = reader.ReadString(nameof(RazorProjectInfo.RootNamespace));
         var documents = reader.ReadImmutableArray(nameof(RazorProjectInfo.Documents), static r => r.ReadNonNullObject(ReadDocumentSnapshotHandleFromProperties));
 
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectWriters.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectWriters.cs
index 71e1d235f6..687a30582b 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectWriters.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/Json/ObjectWriters.cs
@@ -61,7 +61,7 @@ internal static class ObjectWriters
     public static void WriteProperties(JsonDataWriter writer, ProjectSnapshotHandle value)
     {
         writer.Write(nameof(value.ProjectId), value.ProjectId.Id.ToString());
-        writer.WriteObjectIfNotNull(nameof(value.Configuration), value.Configuration, WriteProperties);
+        writer.WriteObject(nameof(value.Configuration), value.Configuration, WriteProperties);
         writer.WriteIfNotNull(nameof(value.RootNamespace), value.RootNamespace);
     }
 
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectSnapshotHandleFormatter.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectSnapshotHandleFormatter.cs
index be80690f40..52763e7780 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectSnapshotHandleFormatter.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectSnapshotHandleFormatter.cs
@@ -23,7 +23,7 @@ internal sealed class ProjectSnapshotHandleFormatter : TopLevelFormatter<Project
         var id = GuidFormatter.Instance.Deserialize(ref reader, options);
         var projectId = ProjectId.CreateFromSerialized(id);
 
-        var configuration = reader.DeserializeOrNull<RazorConfiguration>(options);
+        var configuration = reader.DeserializeOrNull<RazorConfiguration>(options) ?? RazorConfiguration.Default;
         var rootNamespace = CachedStringFormatter.Instance.Deserialize(ref reader, options);
 
         return new(projectId, configuration, rootNamespace);
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectWorkspaceStateFormatter.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectWorkspaceStateFormatter.cs
index af9dfb0f16..60a9894b1d 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectWorkspaceStateFormatter.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/ProjectWorkspaceStateFormatter.cs
@@ -49,7 +49,7 @@ internal sealed class ProjectWorkspaceStateFormatter : ValueFormatter<ProjectWor
         var tagHelpers = builder.DrainToImmutable();
         var csharpLanguageVersion = (LanguageVersion)reader.ReadInt32();
 
-        return new ProjectWorkspaceState(tagHelpers, csharpLanguageVersion);
+        return ProjectWorkspaceState.Create(tagHelpers, csharpLanguageVersion);
     }
 
     public override void Serialize(ref MessagePackWriter writer, ProjectWorkspaceState value, SerializerCachingOptions options)
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/RazorProjectInfoFormatter.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/RazorProjectInfoFormatter.cs
index e79e089b2f..97ca0bd6f2 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/RazorProjectInfoFormatter.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/MessagePack/Formatters/RazorProjectInfoFormatter.cs
@@ -29,8 +29,8 @@ internal sealed class RazorProjectInfoFormatter : TopLevelFormatter<RazorProject
 
         var serializedFilePath = CachedStringFormatter.Instance.Deserialize(ref reader, options).AssumeNotNull();
         var filePath = CachedStringFormatter.Instance.Deserialize(ref reader, options).AssumeNotNull();
-        var configuration = reader.DeserializeOrNull<RazorConfiguration>(options);
-        var projectWorkspaceState = reader.DeserializeOrNull<ProjectWorkspaceState>(options);
+        var configuration = reader.DeserializeOrNull<RazorConfiguration>(options) ?? RazorConfiguration.Default;
+        var projectWorkspaceState = reader.DeserializeOrNull<ProjectWorkspaceState>(options) ?? ProjectWorkspaceState.Default;
         var rootNamespace = CachedStringFormatter.Instance.Deserialize(ref reader, options);
         var displayName = CachedStringFormatter.Instance.Deserialize(ref reader, options).AssumeNotNull();
         var documents = reader.Deserialize<ImmutableArray<DocumentSnapshotHandle>>(options);
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/ProjectSnapshotHandle.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/ProjectSnapshotHandle.cs
index e278dde109..cf8de7e3bc 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/ProjectSnapshotHandle.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.ProjectEngineHost/Serialization/ProjectSnapshotHandle.cs
@@ -10,13 +10,13 @@ namespace Microsoft.AspNetCore.Razor.Serialization;
 internal record ProjectSnapshotHandle
 {
     public ProjectId ProjectId { get; }
-    public RazorConfiguration? Configuration { get; }
+    public RazorConfiguration Configuration { get; }
     public string? RootNamespace { get; }
 
-    public ProjectSnapshotHandle(ProjectId projectId, RazorConfiguration? configuration, string? rootNamespace)
+    public ProjectSnapshotHandle(ProjectId projectId, RazorConfiguration configuration, string? rootNamespace)
     {
         ProjectId = projectId ?? throw new ArgumentNullException(nameof(projectId));
-        Configuration = configuration;
+        Configuration = configuration ?? throw new ArgumentNullException(nameof(configuration));
         RootNamespace = rootNamespace;
     }
 }
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectSnapshotProjectEngineFactory.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectSnapshotProjectEngineFactory.cs
index a01b4e9df6..f229da11c8 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectSnapshotProjectEngineFactory.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectSnapshotProjectEngineFactory.cs
@@ -71,7 +71,7 @@ internal class DefaultProjectSnapshotProjectEngineFactory : ProjectSnapshotProje
             throw new ArgumentNullException(nameof(project));
         }
 
-        return SelectFactory(project.Configuration ?? s_defaultConfiguration, requireSerializable: false);
+        return SelectFactory(project.Configuration, requireSerializable: false);
     }
 
     public override IProjectEngineFactory FindSerializableFactory(IProjectSnapshot project)
@@ -81,7 +81,7 @@ internal class DefaultProjectSnapshotProjectEngineFactory : ProjectSnapshotProje
             throw new ArgumentNullException(nameof(project));
         }
 
-        return SelectFactory(project.Configuration ?? s_defaultConfiguration, requireSerializable: true);
+        return SelectFactory(project.Configuration, requireSerializable: true);
     }
 
     private IProjectEngineFactory SelectFactory(RazorConfiguration configuration, bool requireSerializable = false)
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectWorkspaceStateGenerator.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectWorkspaceStateGenerator.cs
index 69ac0bc13b..322f9ba82e 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectWorkspaceStateGenerator.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/DefaultProjectWorkspaceStateGenerator.cs
@@ -129,7 +129,7 @@ internal class DefaultProjectWorkspaceStateGenerator(ProjectSnapshotManagerDispa
         var telemetryId = Guid.NewGuid();
         _telemetryReporter.ReportEvent("taghelperresolve/begin", Severity.Normal,
             new Property("id", telemetryId),
-            new Property("tagHelperCount", projectSnapshot.ProjectWorkspaceState?.TagHelpers.Length ?? 0));
+            new Property("tagHelperCount", projectSnapshot.ProjectWorkspaceState.TagHelpers.Length));
 
         try
         {
@@ -182,7 +182,7 @@ internal class DefaultProjectWorkspaceStateGenerator(ProjectSnapshotManagerDispa
                         new Property("result", "success"),
                         new Property("tagHelperCount", tagHelpers.Length));
 
-                    workspaceState = new ProjectWorkspaceState(tagHelpers, csharpLanguageVersion);
+                    workspaceState = ProjectWorkspaceState.Create(tagHelpers, csharpLanguageVersion);
                 }
             }
             catch (OperationCanceledException)
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DefaultProjectSnapshotManager.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DefaultProjectSnapshotManager.cs
index febf0b1b8e..669900f11d 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DefaultProjectSnapshotManager.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DefaultProjectSnapshotManager.cs
@@ -442,7 +442,12 @@ internal class DefaultProjectSnapshotManager : ProjectSnapshotManagerBase
                 return false;
             }
 
-            var state = ProjectState.Create(Workspace.Services, projectAddedAction.HostProject);
+            var projectEngineFactory = Workspace.Services.GetRequiredService<ProjectSnapshotProjectEngineFactory>();
+
+            var state = ProjectState.Create(
+                projectEngineFactory,
+                projectAddedAction.HostProject,
+                ProjectWorkspaceState.Default);
             var newEntry = new Entry(state);
 
             oldSnapshot = newSnapshot = newEntry.GetSnapshot();
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs
index 2d6ac4ba14..0eb6a6970c 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs
@@ -8,7 +8,6 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.PooledObjects;
-using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Text;
 
 namespace Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -31,32 +30,24 @@ internal class DocumentState
     private VersionStamp? _version;
 
     public static DocumentState Create(
-        HostWorkspaceServices services,
         HostDocument hostDocument,
         Func<Task<TextAndVersion>>? loader)
     {
-        if (services is null)
-        {
-            throw new ArgumentNullException(nameof(services));
-        }
-
         if (hostDocument is null)
         {
             throw new ArgumentNullException(nameof(hostDocument));
         }
 
-        return new DocumentState(services, hostDocument, null, null, loader);
+        return new DocumentState(hostDocument, null, null, loader);
     }
 
     // Internal for testing
     internal DocumentState(
-        HostWorkspaceServices services,
         HostDocument hostDocument,
         SourceText? text,
         VersionStamp? version,
         Func<Task<TextAndVersion>>? loader)
     {
-        Services = services;
         HostDocument = hostDocument;
         _sourceText = text;
         _version = version;
@@ -66,8 +57,6 @@ internal class DocumentState
 
     public HostDocument HostDocument { get; }
 
-    public HostWorkspaceServices Services { get; }
-
     public bool IsGeneratedOutputResultAvailable => ComputedState.IsResultAvailable == true;
 
     private ComputedStateTracker ComputedState
@@ -168,7 +157,7 @@ internal class DocumentState
 
     public virtual DocumentState WithConfigurationChange()
     {
-        var state = new DocumentState(Services, HostDocument, _sourceText, _version, _loader)
+        var state = new DocumentState(HostDocument, _sourceText, _version, _loader)
         {
             // The source could not have possibly changed.
             _sourceText = _sourceText,
@@ -183,7 +172,7 @@ internal class DocumentState
 
     public virtual DocumentState WithImportsChange()
     {
-        var state = new DocumentState(Services, HostDocument, _sourceText, _version, _loader)
+        var state = new DocumentState(HostDocument, _sourceText, _version, _loader)
         {
             // The source could not have possibly changed.
             _sourceText = _sourceText,
@@ -199,7 +188,7 @@ internal class DocumentState
 
     public virtual DocumentState WithProjectWorkspaceStateChange()
     {
-        var state = new DocumentState(Services, HostDocument, _sourceText, _version, _loader)
+        var state = new DocumentState(HostDocument, _sourceText, _version, _loader)
         {
             // The source could not have possibly changed.
             _sourceText = _sourceText,
@@ -222,7 +211,7 @@ internal class DocumentState
 
         // Do not cache the computed state
 
-        return new DocumentState(Services, HostDocument, sourceText, version, null);
+        return new DocumentState(HostDocument, sourceText, version, null);
     }
 
     public virtual DocumentState WithTextLoader(Func<Task<TextAndVersion>> loader)
@@ -234,7 +223,7 @@ internal class DocumentState
 
         // Do not cache the computed state
 
-        return new DocumentState(Services, HostDocument, null, null, loader);
+        return new DocumentState(HostDocument, null, null, loader);
     }
 
     private ImmutableArray<IDocumentSnapshot> GetImportsCore(ProjectSnapshot project)
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/IProjectSnapshot.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/IProjectSnapshot.cs
index f1eba7b09f..f64fdc7b6b 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/IProjectSnapshot.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/IProjectSnapshot.cs
@@ -13,7 +13,7 @@ internal interface IProjectSnapshot
 {
     ProjectKey Key { get; }
 
-    RazorConfiguration? Configuration { get; }
+    RazorConfiguration Configuration { get; }
     IEnumerable<string> DocumentFilePaths { get; }
 
     /// <summary>
@@ -31,7 +31,7 @@ internal interface IProjectSnapshot
     VersionStamp Version { get; }
     LanguageVersion CSharpLanguageVersion { get; }
     ImmutableArray<TagHelperDescriptor> TagHelpers { get; }
-    ProjectWorkspaceState? ProjectWorkspaceState { get; }
+    ProjectWorkspaceState ProjectWorkspaceState { get; }
 
     RazorProjectEngine GetProjectEngine();
     IDocumentSnapshot? GetDocument(string filePath);
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshot.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshot.cs
index fb49d5167a..01ebf44fe9 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshot.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectSnapshot.cs
@@ -31,7 +31,7 @@ internal class ProjectSnapshot : IProjectSnapshot
 
     public ProjectState State { get; }
 
-    public RazorConfiguration? Configuration => HostProject.Configuration;
+    public RazorConfiguration Configuration => HostProject.Configuration;
 
     public IEnumerable<string> DocumentFilePaths => State.Documents.Keys;
 
@@ -53,7 +53,7 @@ internal class ProjectSnapshot : IProjectSnapshot
 
     public ImmutableArray<TagHelperDescriptor> TagHelpers => State.TagHelpers;
 
-    public ProjectWorkspaceState? ProjectWorkspaceState => State.ProjectWorkspaceState;
+    public ProjectWorkspaceState ProjectWorkspaceState => State.ProjectWorkspaceState;
 
     public virtual IDocumentSnapshot? GetDocument(string filePath)
     {
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs
index 7aaf57fd7b..ff0a9dad6a 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/ProjectState.cs
@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
@@ -13,7 +11,6 @@ using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Utilities;
 using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Text;
 
 namespace Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -36,16 +33,17 @@ internal class ProjectState
     private static readonly ImmutableDictionary<string, ImmutableArray<string>> s_emptyImportsToRelatedDocuments = ImmutableDictionary.Create<string, ImmutableArray<string>>(FilePathNormalizer.Comparer);
     private readonly object _lock;
 
-    private RazorProjectEngine _projectEngine;
+    private readonly ProjectSnapshotProjectEngineFactory _projectEngineFactory;
+    private RazorProjectEngine? _projectEngine;
 
     public static ProjectState Create(
-        HostWorkspaceServices services,
+        ProjectSnapshotProjectEngineFactory projectEngineFactory,
         HostProject hostProject,
-        ProjectWorkspaceState projectWorkspaceState = null)
+        ProjectWorkspaceState projectWorkspaceState)
     {
-        if (services is null)
+        if (projectEngineFactory is null)
         {
-            throw new ArgumentNullException(nameof(services));
+            throw new ArgumentNullException(nameof(projectEngineFactory));
         }
 
         if (hostProject is null)
@@ -53,20 +51,26 @@ internal class ProjectState
             throw new ArgumentNullException(nameof(hostProject));
         }
 
-        return new ProjectState(services, hostProject, projectWorkspaceState);
+        if (projectWorkspaceState is null)
+        {
+            throw new ArgumentNullException(nameof(projectWorkspaceState));
+        }
+
+        return new ProjectState(projectEngineFactory, hostProject, projectWorkspaceState);
     }
 
     private ProjectState(
-        HostWorkspaceServices services,
+        ProjectSnapshotProjectEngineFactory projectEngineFactory,
         HostProject hostProject,
         ProjectWorkspaceState projectWorkspaceState)
     {
-        Services = services;
+        _projectEngineFactory = projectEngineFactory;
         HostProject = hostProject;
         ProjectWorkspaceState = projectWorkspaceState;
         Documents = s_emptyDocuments;
         ImportsToRelatedDocuments = s_emptyImportsToRelatedDocuments;
         Version = VersionStamp.Create();
+        ProjectWorkspaceStateVersion = Version;
         DocumentCollectionVersion = Version;
 
         _lock = new object();
@@ -100,7 +104,12 @@ internal class ProjectState
             throw new ArgumentNullException(nameof(importsToRelatedDocuments));
         }
 
-        Services = older.Services;
+        if (projectWorkspaceState is null)
+        {
+            throw new ArgumentNullException(nameof(projectWorkspaceState));
+        }
+
+        _projectEngineFactory = older._projectEngineFactory;
         Version = older.Version.GetNewerVersion();
 
         HostProject = hostProject;
@@ -133,7 +142,7 @@ internal class ProjectState
 
         if ((difference & ClearProjectWorkspaceStateVersionMask) == 0 ||
             ProjectWorkspaceState == older.ProjectWorkspaceState ||
-            ProjectWorkspaceState?.Equals(older.ProjectWorkspaceState) == true)
+            ProjectWorkspaceState.Equals(older.ProjectWorkspaceState))
         {
             ProjectWorkspaceStateVersion = older.ProjectWorkspaceStateVersion;
         }
@@ -161,11 +170,9 @@ internal class ProjectState
 
     public ProjectWorkspaceState ProjectWorkspaceState { get; }
 
-    public HostWorkspaceServices Services { get; }
+    public ImmutableArray<TagHelperDescriptor> TagHelpers => ProjectWorkspaceState.TagHelpers;
 
-    public ImmutableArray<TagHelperDescriptor> TagHelpers => ProjectWorkspaceState?.TagHelpers ?? ImmutableArray<TagHelperDescriptor>.Empty;
-
-    public LanguageVersion CSharpLanguageVersion => ProjectWorkspaceState?.CSharpLanguageVersion ?? LanguageVersion.Default;
+    public LanguageVersion CSharpLanguageVersion => ProjectWorkspaceState.CSharpLanguageVersion;
 
     /// <summary>
     /// Gets the version of this project, INCLUDING content changes. The <see cref="Version"/> is
@@ -190,6 +197,19 @@ internal class ProjectState
             }
 
             return _projectEngine;
+
+            RazorProjectEngine CreateProjectEngine()
+            {
+                return _projectEngineFactory.Create(
+                    HostProject.Configuration,
+                    Path.GetDirectoryName(HostProject.FilePath),
+                    configure: builder =>
+                    {
+                        builder.SetRootNamespace(HostProject.RootNamespace);
+                        builder.SetCSharpLanguageVersion(CSharpLanguageVersion);
+                        builder.SetSupportLocalizedComponentNames();
+                    });
+            }
         }
     }
 
@@ -221,7 +241,7 @@ internal class ProjectState
             return this;
         }
 
-        var documents = Documents.Add(hostDocument.FilePath, DocumentState.Create(Services, hostDocument, loader));
+        var documents = Documents.Add(hostDocument.FilePath, DocumentState.Create(hostDocument, loader));
 
         // Compute the effect on the import map
         var importTargetPaths = GetImportDocumentTargetPaths(hostDocument);
@@ -360,7 +380,7 @@ internal class ProjectState
             return this;
         }
 
-        if (ProjectWorkspaceState != null && ProjectWorkspaceState.Equals(projectWorkspaceState))
+        if (ProjectWorkspaceState.Equals(projectWorkspaceState))
         {
             return this;
         }
@@ -409,20 +429,6 @@ internal class ProjectState
         return importsToRelatedDocuments;
     }
 
-    private RazorProjectEngine CreateProjectEngine()
-    {
-        var factory = Services.GetRequiredService<ProjectSnapshotProjectEngineFactory>();
-        return factory.Create(
-            HostProject.Configuration,
-            Path.GetDirectoryName(HostProject.FilePath),
-            configure: builder =>
-            {
-                builder.SetRootNamespace(HostProject.RootNamespace);
-                builder.SetCSharpLanguageVersion(CSharpLanguageVersion);
-                builder.SetSupportLocalizedComponentNames();
-            });
-    }
-
     public List<string> GetImportDocumentTargetPaths(HostDocument hostDocument)
     {
         var projectEngine = ProjectEngine;
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/TagHelperResolverFactory.Resolver.cs b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/TagHelperResolverFactory.Resolver.cs
index 8ed68a488a..0500776726 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/TagHelperResolverFactory.Resolver.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/TagHelperResolverFactory.Resolver.cs
@@ -22,8 +22,6 @@ internal partial class TagHelperResolverFactory
             Project workspaceProject,
             IProjectSnapshot projectSnapshot,
             CancellationToken cancellationToken)
-            => projectSnapshot.Configuration is not null
-                ? _resolver.GetTagHelpersAsync(workspaceProject, projectSnapshot.GetProjectEngine(), cancellationToken)
-                : new(ImmutableArray<TagHelperDescriptor>.Empty);
+            => _resolver.GetTagHelpersAsync(workspaceProject, projectSnapshot.GetProjectEngine(), cancellationToken);
     }
 }
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/OOPTagHelperResolver.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/OOPTagHelperResolver.cs
index 7b9949b4db..ae4fb30a7c 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/OOPTagHelperResolver.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/OOPTagHelperResolver.cs
@@ -41,11 +41,6 @@ internal class OOPTagHelperResolver : ITagHelperResolver
         IProjectSnapshot projectSnapshot,
         CancellationToken cancellationToken)
     {
-        if (projectSnapshot.Configuration is null)
-        {
-            return ImmutableArray<TagHelperDescriptor>.Empty;
-        }
-
         // Not every custom factory supports the OOP host. Our priority system should work like this:
         //
         // 1. Use custom factory out of process
diff --git a/src/Razor/src/Microsoft.VisualStudio.Editor.Razor/EphemeralProjectSnapshot.cs b/src/Razor/src/Microsoft.VisualStudio.Editor.Razor/EphemeralProjectSnapshot.cs
index d1dfdec661..3fd1ec69c5 100644
--- a/src/Razor/src/Microsoft.VisualStudio.Editor.Razor/EphemeralProjectSnapshot.cs
+++ b/src/Razor/src/Microsoft.VisualStudio.Editor.Razor/EphemeralProjectSnapshot.cs
@@ -44,7 +44,7 @@ internal class EphemeralProjectSnapshot : IProjectSnapshot
 
     public ProjectKey Key { get; }
 
-    public RazorConfiguration? Configuration => FallbackRazorConfiguration.Latest;
+    public RazorConfiguration Configuration => FallbackRazorConfiguration.Latest;
 
     public IEnumerable<string> DocumentFilePaths => Array.Empty<string>();
 
@@ -58,11 +58,11 @@ internal class EphemeralProjectSnapshot : IProjectSnapshot
 
     public VersionStamp Version => VersionStamp.Default;
 
-    public LanguageVersion CSharpLanguageVersion => LanguageVersion.Default;
+    public LanguageVersion CSharpLanguageVersion => ProjectWorkspaceState.CSharpLanguageVersion;
 
-    public ImmutableArray<TagHelperDescriptor> TagHelpers => ImmutableArray<TagHelperDescriptor>.Empty;
+    public ImmutableArray<TagHelperDescriptor> TagHelpers => ProjectWorkspaceState.TagHelpers;
 
-    public ProjectWorkspaceState? ProjectWorkspaceState => null;
+    public ProjectWorkspaceState ProjectWorkspaceState => ProjectWorkspaceState.Default;
 
     public IDocumentSnapshot? GetDocument(string filePath)
     {
diff --git a/src/Razor/src/Microsoft.VisualStudio.LiveShare.Razor/Host/DefaultProjectSnapshotManagerProxy.cs b/src/Razor/src/Microsoft.VisualStudio.LiveShare.Razor/Host/DefaultProjectSnapshotManagerProxy.cs
index 62df6d7e7f..f20b18071b 100644
--- a/src/Razor/src/Microsoft.VisualStudio.LiveShare.Razor/Host/DefaultProjectSnapshotManagerProxy.cs
+++ b/src/Razor/src/Microsoft.VisualStudio.LiveShare.Razor/Host/DefaultProjectSnapshotManagerProxy.cs
@@ -6,7 +6,6 @@ using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Razor;
 using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -125,10 +124,10 @@ internal class DefaultProjectSnapshotManagerProxy : IProjectSnapshotManagerProxy
             return null;
         }
 
-        var projectWorkspaceState = new ProjectWorkspaceState(project.TagHelpers, project.CSharpLanguageVersion);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(project.TagHelpers, project.CSharpLanguageVersion);
         var projectFilePath = _session.ConvertLocalPathToSharedUri(project.FilePath);
         var intermediateOutputPath = _session.ConvertLocalPathToSharedUri(project.IntermediateOutputPath);
-        var projectHandleProxy = new ProjectSnapshotHandleProxy(projectFilePath, intermediateOutputPath, project.Configuration.AssumeNotNull(), project.RootNamespace, projectWorkspaceState);
+        var projectHandleProxy = new ProjectSnapshotHandleProxy(projectFilePath, intermediateOutputPath, project.Configuration, project.RootNamespace, projectWorkspaceState);
         return projectHandleProxy;
     }
 
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs
index b063a74806..502ce7c7f3 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs
@@ -1178,7 +1178,7 @@ public class CodeActionEndToEndTest(ITestOutputHelper testOutput) : SingleServer
                 return null;
             }
 
-            var projectWorkspaceState = new ProjectWorkspaceState(_tagHelperDescriptors.ToImmutableArray(), LanguageVersion.Default);
+            var projectWorkspaceState = ProjectWorkspaceState.Create(_tagHelperDescriptors.ToImmutableArray());
             var testDocumentSnapshot = TestDocumentSnapshot.Create(FilePath, CodeDocument.GetSourceText().ToString(), CodeAnalysis.VersionStamp.Default, projectWorkspaceState);
             testDocumentSnapshot.With(CodeDocument);
 
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Completion/TagHelperTooltipFactoryBaseTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Completion/TagHelperTooltipFactoryBaseTest.cs
index 83e095872c..8b7a37932c 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Completion/TagHelperTooltipFactoryBaseTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Completion/TagHelperTooltipFactoryBaseTest.cs
@@ -359,7 +359,7 @@ There is no xml, but I got you this < and the >.
         var tagHelperTypeName = "TestNamespace.TestTagHelper";
         builder.Metadata(TypeName(tagHelperTypeName));
         var tagHelpers = ImmutableArray.Create(builder.Build());
-        var projectWorkspaceState = new ProjectWorkspaceState(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.Default);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers);
 
         var baseDirectory = PathUtilities.CreateRootedPath("path", "to");
         var razorFilePath = Path.Combine(baseDirectory, "file.razor");
@@ -383,7 +383,7 @@ There is no xml, but I got you this < and the >.
         var tagHelperTypeName = "TestNamespace.TestTagHelper";
         builder.Metadata(TypeName(tagHelperTypeName));
         var tagHelpers = ImmutableArray.Create(builder.Build());
-        var projectWorkspaceState = new ProjectWorkspaceState(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.Default);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers);
 
         var baseDirectory = PathUtilities.CreateRootedPath("path", "to");
         var razorFilePath = Path.Combine(baseDirectory, "file.razor");
@@ -420,7 +420,7 @@ There is no xml, but I got you this < and the >.
         var tagHelperTypeName = "TestNamespace.TestTagHelper";
         builder.Metadata(TypeName(tagHelperTypeName));
         var tagHelpers = ImmutableArray.Create(builder.Build());
-        var projectWorkspaceState = new ProjectWorkspaceState(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.Default);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers);
 
         var baseDirectory = PathUtilities.CreateRootedPath("path", "to");
         var razorFilePath = Path.Combine(baseDirectory, "file.razor");
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DefaultRazorProjectServiceTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DefaultRazorProjectServiceTest.cs
index 2e783d71e1..02c9261091 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DefaultRazorProjectServiceTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/DefaultRazorProjectServiceTest.cs
@@ -38,7 +38,7 @@ public class DefaultRazorProjectServiceTest(ITestOutputHelper testOutput) : Lang
         var hostProject = new HostProject("C:/path/to/project.csproj", "C:/path/to/obj", RazorConfiguration.Default, "TestRootNamespace");
         projectManager.ProjectAdded(hostProject);
         var projectService = CreateProjectService(new TestSnapshotResolver(), projectManager);
-        var projectWorkspaceState = new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.LatestMajor);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(LanguageVersion.LatestMajor);
 
         // Act
         await RunOnDispatcherThreadAsync(() =>
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Hover/HoverInfoServiceTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Hover/HoverInfoServiceTest.cs
index 8f4d03a9a8..d1a7cd6c04 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Hover/HoverInfoServiceTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Hover/HoverInfoServiceTest.cs
@@ -975,7 +975,7 @@ public class HoverInfoServiceTest(ITestOutputHelper testOutput) : TagHelperServi
                 """;
         var path = "C:/text.razor";
         var codeDocument = CreateCodeDocument(txt, path, DefaultTagHelpers);
-        var projectWorkspaceState = new ProjectWorkspaceState(DefaultTagHelpers, LanguageVersion.Default);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(DefaultTagHelpers);
         var projectSnapshot = TestProjectSnapshot.Create("C:/project.csproj", projectWorkspaceState);
         var sourceText = SourceText.From(txt);
 
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs
index 7ff6921b7b..454a0d13fe 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/OpenDocumentGeneratorTest.cs
@@ -135,7 +135,7 @@ public class OpenDocumentGeneratorTest : LanguageServerTestBase
 
             // Act
             projectManager.ProjectWorkspaceStateChanged(_hostProject1.Key,
-                new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp8));
+                ProjectWorkspaceState.Create(LanguageVersion.CSharp8));
         }, DisposalToken);
 
         // Assert
@@ -162,7 +162,7 @@ public class OpenDocumentGeneratorTest : LanguageServerTestBase
 
             // Act
             projectManager.ProjectWorkspaceStateChanged(_hostProject1.Key,
-                new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp8));
+                ProjectWorkspaceState.Create(LanguageVersion.CSharp8));
         }, DisposalToken);
 
         // Assert
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationFileChangeEventArgsTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationFileChangeEventArgsTest.cs
index 4a15fb89d5..c17a1b4508 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationFileChangeEventArgsTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationFileChangeEventArgsTest.cs
@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System.Collections.Immutable;
+using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.LanguageServer.Common;
 using Microsoft.AspNetCore.Razor.LanguageServer.Serialization;
 using Microsoft.AspNetCore.Razor.ProjectSystem;
@@ -25,10 +26,10 @@ public class ProjectConfigurationFileChangeEventArgsTest(ITestOutputHelper testO
             .Returns(new RazorProjectInfo(
                 "/path/to/obj/project.razor.bin",
                 "c:/path/to/project.csproj",
-                configuration: null,
+                configuration: RazorConfiguration.Default,
                 rootNamespace: null,
                 displayName: "project",
-                projectWorkspaceState: null,
+                projectWorkspaceState: ProjectWorkspaceState.Default,
                 documents: ImmutableArray<DocumentSnapshotHandle>.Empty));
 
         var args = new ProjectConfigurationFileChangeEventArgs(
@@ -53,10 +54,10 @@ public class ProjectConfigurationFileChangeEventArgsTest(ITestOutputHelper testO
         var projectInfo = new RazorProjectInfo(
             "/path/to/ORIGINAL/obj/project.razor.bin",
             "c:/path/to/project.csproj",
-            configuration: null,
+            configuration: RazorConfiguration.Default,
             rootNamespace: null,
             displayName: "project",
-            projectWorkspaceState: null,
+            projectWorkspaceState: ProjectWorkspaceState.Default,
             documents: ImmutableArray<DocumentSnapshotHandle>.Empty);
 
         deserializerMock
@@ -84,10 +85,10 @@ public class ProjectConfigurationFileChangeEventArgsTest(ITestOutputHelper testO
         var projectInfo = new RazorProjectInfo(
             "/path/to/obj/project.razor.bin",
             "c:/path/to/project.csproj",
-            configuration: null,
+            configuration: RazorConfiguration.Default,
             rootNamespace: null,
             displayName: "project",
-            projectWorkspaceState: null,
+            projectWorkspaceState: ProjectWorkspaceState.Default,
             documents: ImmutableArray<DocumentSnapshotHandle>.Empty);
 
         deserializerMock
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationStateSynchronizerTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationStateSynchronizerTest.cs
index 788596f356..74d6b429eb 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationStateSynchronizerTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/ProjectConfigurationStateSynchronizerTest.cs
@@ -55,7 +55,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
             RazorConfiguration.Default,
             rootNamespace: "TestRootNamespace",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp5),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp5),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
         var intermediateOutputPath = Path.GetDirectoryName(FilePathNormalizer.Normalize(projectInfo.SerializedFilePath));
         var projectKey = TestProjectKey.Create(intermediateOutputPath);
@@ -148,7 +148,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
             RazorConfiguration.Default,
             rootNamespace: "TestRootNamespace",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp5),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp5),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
         var intermediateOutputPath = Path.GetDirectoryName(FilePathNormalizer.Normalize(projectInfo.SerializedFilePath));
         var projectKey = TestProjectKey.Create(intermediateOutputPath);
@@ -196,7 +196,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
             RazorConfiguration.Default,
             rootNamespace: "TestRootNamespace",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp5),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp5),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
         var intermediateOutputPath = Path.GetDirectoryName(FilePathNormalizer.Normalize(projectInfo.SerializedFilePath));
         var projectKey = TestProjectKey.Create(intermediateOutputPath);
@@ -264,7 +264,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
             RazorConfiguration.Default,
             rootNamespace: "TestRootNamespace",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp5),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp5),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
         var intermediateOutputPath = Path.GetDirectoryName(FilePathNormalizer.Normalize(initialProjectInfo.SerializedFilePath));
         var projectKey = TestProjectKey.Create(intermediateOutputPath);
@@ -295,7 +295,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
                 Array.Empty<RazorExtension>()),
             rootNamespace: "TestRootNamespace2",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp6),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp6),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
         projectService
             .Setup(service => service.UpdateProject(
@@ -348,7 +348,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
             RazorConfiguration.Default,
             rootNamespace: "TestRootNamespace",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp5),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp5),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
         var intermediateOutputPath = Path.GetDirectoryName(FilePathNormalizer.Normalize(initialProjectInfo.SerializedFilePath));
         var projectKey = TestProjectKey.Create(intermediateOutputPath);
@@ -379,7 +379,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
                 Array.Empty<RazorExtension>()),
             rootNamespace: "TestRootNamespace2",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp6),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp6),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
 
         // This is the request that happens when the server is reset
@@ -463,7 +463,7 @@ public class ProjectConfigurationStateSynchronizerTest(ITestOutputHelper testOut
             RazorConfiguration.Default,
             rootNamespace: "TestRootNamespace",
             displayName: "project",
-            new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, LanguageVersion.CSharp5),
+            ProjectWorkspaceState.Create(LanguageVersion.CSharp5),
             ImmutableArray<DocumentSnapshotHandle>.Empty);
         var intermediateOutputPath = Path.GetDirectoryName(FilePathNormalizer.Normalize(projectInfo.SerializedFilePath));
         var projectKey = TestProjectKey.Create(intermediateOutputPath);
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs
index 4cd3656d47..c49e233151 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs
@@ -609,7 +609,7 @@ public class RenameEndpointTest : LanguageServerTestBase
         namespaceNode.Content = rootNamespaceName;
 
         var sourceText = SourceText.From(item.Content);
-        var projectWorkspaceState = new ProjectWorkspaceState(tagHelpers, LanguageVersion.Default);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers);
         var projectSnapshot = TestProjectSnapshot.Create("C:/project.csproj", projectWorkspaceState);
         var snapshot = Mock.Of<IDocumentSnapshot>(d =>
             d.GetGeneratedOutputAsync() == Task.FromResult(codeDocument) &&
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/Serialization/ProjectSnapshotHandleSerializationTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/Serialization/ProjectSnapshotHandleSerializationTest.cs
index 167386b7ef..d5be3fe57a 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/Serialization/ProjectSnapshotHandleSerializationTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/Serialization/ProjectSnapshotHandleSerializationTest.cs
@@ -62,7 +62,7 @@ public class ProjectSnapshotHandleSerializationTest(ITestOutputHelper testOutput
     {
         // Arrange
         var projectId = ProjectId.CreateNewId();
-        var expectedSnapshot = new ProjectSnapshotHandle(projectId, null, null);
+        var expectedSnapshot = new ProjectSnapshotHandle(projectId, RazorConfiguration.Default, null);
 
         // Act
         var bytes = MessagePackConvert.Serialize(expectedSnapshot, s_options);
@@ -71,7 +71,7 @@ public class ProjectSnapshotHandleSerializationTest(ITestOutputHelper testOutput
         // Assert
         Assert.NotNull(actualSnapshot);
         Assert.Equal(expectedSnapshot.ProjectId, actualSnapshot.ProjectId);
-        Assert.Null(actualSnapshot.Configuration);
+        Assert.NotNull(actualSnapshot.Configuration);
         Assert.Null(actualSnapshot.RootNamespace);
     }
 }
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/SerializationTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/SerializationTest.cs
index 2170588741..310dbec31f 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/SerializationTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.ProjectEngineHost.Test/SerializationTest.cs
@@ -30,7 +30,7 @@ public class SerializationTest : ToolingTestBase
         };
 
         _configuration = RazorConfiguration.Create(languageVersion, "Custom", extensions);
-        _projectWorkspaceState = new ProjectWorkspaceState(ImmutableArray.Create(
+        _projectWorkspaceState = ProjectWorkspaceState.Create(ImmutableArray.Create(
             TagHelperDescriptorBuilder.Create("Test", "TestAssembly").Build()),
             csharpLanguageVersion: LanguageVersion.LatestMajor);
     }
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestDocumentSnapshot.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestDocumentSnapshot.cs
index 08d3387f6b..527abb034f 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestDocumentSnapshot.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestDocumentSnapshot.cs
@@ -7,7 +7,6 @@ using System.IO;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.ProjectSystem;
-using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.AspNetCore.Razor.Utilities;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -33,8 +32,6 @@ internal class TestDocumentSnapshot : DocumentSnapshot
 
     public static TestDocumentSnapshot Create(string filePath, string text, VersionStamp version, TestProjectSnapshot projectSnapshot)
     {
-        using var testWorkspace = TestWorkspace.Create();
-
         var targetPath = Path.GetDirectoryName(projectSnapshot.FilePath) is string projectDirectory && filePath.StartsWith(projectDirectory)
             ? filePath[projectDirectory.Length..]
             : filePath;
@@ -42,7 +39,6 @@ internal class TestDocumentSnapshot : DocumentSnapshot
         var hostDocument = new HostDocument(filePath, targetPath);
         var sourceText = SourceText.From(text);
         var documentState = new DocumentState(
-            testWorkspace.Services,
             hostDocument,
             SourceText.From(text),
             version,
@@ -52,7 +48,7 @@ internal class TestDocumentSnapshot : DocumentSnapshot
         return testDocument;
     }
 
-    internal static TestDocumentSnapshot Create(Workspace workspace, ProjectSnapshot projectSnapshot, string filePath, string text = "", VersionStamp? version = null)
+    internal static TestDocumentSnapshot Create(ProjectSnapshot projectSnapshot, string filePath, string text = "", VersionStamp? version = null)
     {
         version ??= VersionStamp.Default;
 
@@ -66,7 +62,6 @@ internal class TestDocumentSnapshot : DocumentSnapshot
         var hostDocument = new HostDocument(filePath, targetPath);
         var sourceText = SourceText.From(text);
         var documentState = new DocumentState(
-            workspace.Services,
             hostDocument,
             SourceText.From(text),
             version,
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshot.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshot.cs
index cef5cabdca..f5a6932eb4 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshot.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshot.cs
@@ -2,14 +2,11 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.ProjectSystem;
-using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.CodeAnalysis;
-using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 using Microsoft.CodeAnalysis.Text;
 
@@ -28,31 +25,19 @@ internal class TestProjectSnapshot : ProjectSnapshot
         string intermediateOutputPath,
         string[] documentFilePaths,
         RazorConfiguration configuration,
-        ProjectWorkspaceState? projectWorkspaceState,
+        ProjectWorkspaceState? projectWorkspaceState = null,
         string? displayName = null)
     {
-        var workspaceServices = new List<IWorkspaceService>()
-        {
-            new TestProjectSnapshotProjectEngineFactory(),
-        };
-
-        var languageServices = new List<ILanguageService>();
-
-        var hostServices = TestServices.Create(workspaceServices, languageServices);
-        using var workspace = TestWorkspace.Create(hostServices);
+        var projectEngineFactory = new TestProjectSnapshotProjectEngineFactory();
         var hostProject = new HostProject(filePath, intermediateOutputPath, configuration, "TestRootNamespace", displayName);
-        var state = ProjectState.Create(workspace.Services, hostProject);
+        var state = ProjectState.Create(projectEngineFactory, hostProject, projectWorkspaceState ?? ProjectWorkspaceState.Default);
+
         foreach (var documentFilePath in documentFilePaths)
         {
             var hostDocument = new HostDocument(documentFilePath, documentFilePath);
             state = state.WithAddedHostDocument(hostDocument, () => Task.FromResult(TextAndVersion.Create(SourceText.From(string.Empty), VersionStamp.Default)));
         }
 
-        if (projectWorkspaceState is not null)
-        {
-            state = state.WithProjectWorkspaceState(projectWorkspaceState);
-        }
-
         var testProject = new TestProjectSnapshot(state);
 
         return testProject;
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshotManager.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshotManager.cs
index 1c5c335ef9..c9e962a724 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshotManager.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/TestProjectSnapshotManager.cs
@@ -38,7 +38,7 @@ internal class TestProjectSnapshotManager : DefaultProjectSnapshotManager
 
     public TestDocumentSnapshot CreateAndAddDocument(ProjectSnapshot projectSnapshot, string filePath)
     {
-        var documentSnapshot = TestDocumentSnapshot.Create(Workspace, projectSnapshot, filePath);
+        var documentSnapshot = TestDocumentSnapshot.Create(projectSnapshot, filePath);
         DocumentAdded(projectSnapshot.Key, documentSnapshot.HostDocument, new DocumentSnapshotTextLoader(documentSnapshot));
 
         return documentSnapshot;
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/DocumentExcerptServiceTestBase.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/DocumentExcerptServiceTestBase.cs
index e74bd8be7f..4711ae6912 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/DocumentExcerptServiceTestBase.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/DocumentExcerptServiceTestBase.cs
@@ -6,6 +6,7 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
+using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 using Microsoft.CodeAnalysis.Text;
@@ -40,7 +41,7 @@ public abstract class DocumentExcerptServiceTestBase(ITestOutputHelper testOutpu
     private (IDocumentSnapshot primary, Document secondary) InitializeDocument(SourceText sourceText)
     {
         var project = new ProjectSnapshot(
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, () => Task.FromResult(TextAndVersion.Create(sourceText, VersionStamp.Create()))));
 
         var primary = project.GetDocument(_hostDocument.FilePath).AssumeNotNull();
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/WorkspaceTestBase.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/WorkspaceTestBase.cs
index 7513f24d50..febf5e4d81 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/WorkspaceTestBase.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/Workspaces/WorkspaceTestBase.cs
@@ -7,6 +7,7 @@ using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Test.Common.ProjectSystem;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Host;
+using Microsoft.CodeAnalysis.Razor;
 using Xunit.Abstractions;
 
 namespace Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
@@ -16,6 +17,7 @@ public abstract class WorkspaceTestBase : ToolingTestBase
     private bool _initialized;
     private HostServices? _hostServices;
     private Workspace? _workspace;
+    private ProjectSnapshotProjectEngineFactory? _projectEngineFactory;
 
     protected WorkspaceTestBase(ITestOutputHelper testOutput)
         : base(testOutput)
@@ -40,6 +42,15 @@ public abstract class WorkspaceTestBase : ToolingTestBase
         }
     }
 
+    private protected ProjectSnapshotProjectEngineFactory ProjectEngineFactory
+    {
+        get
+        {
+            EnsureInitialized();
+            return _projectEngineFactory;
+        }
+    }
+
     protected virtual void ConfigureWorkspaceServices(List<IWorkspaceService> services)
     {
     }
@@ -56,22 +67,25 @@ public abstract class WorkspaceTestBase : ToolingTestBase
     {
     }
 
-    [MemberNotNull(nameof(_hostServices), nameof(_workspace))]
+    [MemberNotNull(nameof(_hostServices), nameof(_workspace), nameof(_projectEngineFactory))]
     private void EnsureInitialized()
     {
         if (_initialized)
         {
             _hostServices.AssumeNotNull();
             _workspace.AssumeNotNull();
+            _projectEngineFactory.AssumeNotNull();
             return;
         }
 
+        _projectEngineFactory = new TestProjectSnapshotProjectEngineFactory()
+        {
+            Configure = ConfigureProjectEngine,
+        };
+
         var workspaceServices = new List<IWorkspaceService>()
         {
-            new TestProjectSnapshotProjectEngineFactory()
-            {
-                Configure = ConfigureProjectEngine,
-            },
+            _projectEngineFactory,
         };
         ConfigureWorkspaceServices(workspaceServices);
 
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultDocumentSnapshotTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultDocumentSnapshotTest.cs
index 2c6463daf5..aa943d27f4 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultDocumentSnapshotTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultDocumentSnapshotTest.cs
@@ -6,6 +6,7 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common;
 using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.CodeAnalysis.Host;
@@ -41,21 +42,21 @@ public class DefaultDocumentSnapshotTest : WorkspaceTestBase
         _legacyHostDocument = new HostDocument(TestProjectData.SomeProjectFile1);
         _nestedComponentHostDocument = new HostDocument(TestProjectData.SomeProjectNestedComponentFile3);
 
-        var projectState = ProjectState.Create(Workspace.Services, TestProjectData.SomeProject);
+        var projectState = ProjectState.Create(ProjectEngineFactory, TestProjectData.SomeProject, ProjectWorkspaceState.Default);
         var project = new ProjectSnapshot(projectState);
 
         var textAndVersion = TextAndVersion.Create(_sourceText, _version);
 
-        var documentState = DocumentState.Create(Workspace.Services, _legacyHostDocument, () => Task.FromResult(textAndVersion));
+        var documentState = DocumentState.Create(_legacyHostDocument, () => Task.FromResult(textAndVersion));
         _legacyDocument = new DocumentSnapshot(project, documentState);
 
-        documentState = DocumentState.Create(Workspace.Services, _componentHostDocument, () => Task.FromResult(textAndVersion));
+        documentState = DocumentState.Create(_componentHostDocument, () => Task.FromResult(textAndVersion));
         _componentDocument = new DocumentSnapshot(project, documentState);
 
-        documentState = DocumentState.Create(Workspace.Services, _componentCshtmlHostDocument, () => Task.FromResult(textAndVersion));
+        documentState = DocumentState.Create(_componentCshtmlHostDocument, () => Task.FromResult(textAndVersion));
         _componentCshtmlDocument = new DocumentSnapshot(project, documentState);
 
-        documentState = DocumentState.Create(Workspace.Services, _nestedComponentHostDocument, () => Task.FromResult(textAndVersion));
+        documentState = DocumentState.Create(_nestedComponentHostDocument, () => Task.FromResult(textAndVersion));
         _nestedComponentDocument = new DocumentSnapshot(project, documentState);
     }
 
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultProjectSnapshotTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultProjectSnapshotTest.cs
index 43e40946f5..0c3f632206 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultProjectSnapshotTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DefaultProjectSnapshotTest.cs
@@ -29,9 +29,8 @@ public class DefaultProjectSnapshotTest : WorkspaceTestBase
         _tagHelperResolver = new TestTagHelperResolver();
 
         _hostProject = new HostProject(TestProjectData.SomeProject.FilePath, TestProjectData.SomeProject.IntermediateOutputPath, FallbackRazorConfiguration.MVC_2_0, TestProjectData.SomeProject.RootNamespace);
-        _projectWorkspaceState = new ProjectWorkspaceState(ImmutableArray.Create(
-            TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()),
-            csharpLanguageVersion: default);
+        _projectWorkspaceState = ProjectWorkspaceState.Create(ImmutableArray.Create(
+            TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()));
 
         _documents =
         [
@@ -57,7 +56,7 @@ public class DefaultProjectSnapshotTest : WorkspaceTestBase
     public void ProjectSnapshot_CachesDocumentSnapshots()
     {
         // Arrange
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[0], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader);
@@ -78,7 +77,7 @@ public class DefaultProjectSnapshotTest : WorkspaceTestBase
     public void IsImportDocument_NonImportDocument_ReturnsFalse()
     {
         // Arrange
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[0], DocumentState.EmptyLoader);
         var snapshot = new ProjectSnapshot(state);
 
@@ -95,7 +94,7 @@ public class DefaultProjectSnapshotTest : WorkspaceTestBase
     public void IsImportDocument_ImportDocument_ReturnsTrue()
     {
         // Arrange
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[0], DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectImportFile, DocumentState.EmptyLoader);
         var snapshot = new ProjectSnapshot(state);
@@ -113,7 +112,7 @@ public class DefaultProjectSnapshotTest : WorkspaceTestBase
     public void GetRelatedDocuments_NonImportDocument_ReturnsEmpty()
     {
         // Arrange
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[0], DocumentState.EmptyLoader);
         var snapshot = new ProjectSnapshot(state);
 
@@ -130,7 +129,7 @@ public class DefaultProjectSnapshotTest : WorkspaceTestBase
     public void GetRelatedDocuments_ImportDocument_ReturnsRelated()
     {
         // Arrange
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[0], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectImportFile, DocumentState.EmptyLoader);
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs
index fc47a222bb..b529652580 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/DocumentStateTest.cs
@@ -1,60 +1,34 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
-using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Razor.Language;
-using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common;
-using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
-using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Text;
 using Xunit;
 using Xunit.Abstractions;
 
 namespace Microsoft.CodeAnalysis.Razor.ProjectSystem;
 
-public class DocumentStateTest : WorkspaceTestBase
+public class DocumentStateTest : ToolingTestBase
 {
     private readonly HostDocument _hostDocument;
-    private readonly HostProject _hostProject;
-    private readonly HostProject _hostProjectWithConfigurationChange;
-    private readonly ProjectWorkspaceState _projectWorkspaceState;
-    private readonly TestTagHelperResolver _tagHelperResolver;
     private readonly Func<Task<TextAndVersion>> _textLoader;
     private readonly SourceText _text;
 
     public DocumentStateTest(ITestOutputHelper testOutput)
         : base(testOutput)
     {
-        _tagHelperResolver = new TestTagHelperResolver();
-
-        _hostProject = new HostProject(TestProjectData.SomeProject.FilePath, TestProjectData.SomeProject.IntermediateOutputPath, FallbackRazorConfiguration.MVC_2_0, TestProjectData.SomeProject.RootNamespace);
-        _hostProjectWithConfigurationChange = new HostProject(TestProjectData.SomeProject.FilePath, TestProjectData.SomeProject.IntermediateOutputPath, FallbackRazorConfiguration.MVC_1_0, TestProjectData.SomeProject.RootNamespace);
-        _projectWorkspaceState = new ProjectWorkspaceState(ImmutableArray.Create(
-            TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()),
-            csharpLanguageVersion: default);
-
         _hostDocument = TestProjectData.SomeProjectFile1;
-
         _text = SourceText.From("Hello, world!");
         _textLoader = () => Task.FromResult(TextAndVersion.Create(_text, VersionStamp.Create()));
     }
 
-    protected override void ConfigureWorkspaceServices(List<IWorkspaceService> services)
-    {
-        services.Add(_tagHelperResolver);
-    }
-
     [Fact]
     public async Task DocumentState_CreatedNew_HasEmptyText()
     {
         // Arrange & Act
-        var state = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader);
+        var state = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader);
 
         // Assert
         var text = await state.GetTextAsync();
@@ -65,7 +39,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public async Task DocumentState_WithText_CreatesNewState()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader);
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader);
 
         // Act
         var state = original.WithText(_text, VersionStamp.Create());
@@ -79,7 +53,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public async Task DocumentState_WithTextLoader_CreatesNewState()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader);
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader);
 
         // Act
         var state = original.WithTextLoader(_textLoader);
@@ -93,7 +67,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public void DocumentState_WithConfigurationChange_CachesSnapshotText()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader)
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
             .WithText(_text, VersionStamp.Create());
 
         // Act
@@ -108,7 +82,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public async Task DocumentState_WithConfigurationChange_CachesLoadedText()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader)
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
             .WithTextLoader(_textLoader);
 
         await original.GetTextAsync();
@@ -125,7 +99,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public void DocumentState_WithImportsChange_CachesSnapshotText()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader)
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
             .WithText(_text, VersionStamp.Create());
 
         // Act
@@ -140,7 +114,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public async Task DocumentState_WithImportsChange_CachesLoadedText()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader)
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
             .WithTextLoader(_textLoader);
 
         await original.GetTextAsync();
@@ -157,7 +131,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public void DocumentState_WithProjectWorkspaceStateChange_CachesSnapshotText()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader)
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
             .WithText(_text, VersionStamp.Create());
 
         // Act
@@ -172,7 +146,7 @@ public class DocumentStateTest : WorkspaceTestBase
     public async Task DocumentState_WithProjectWorkspaceStateChange_CachesLoadedText()
     {
         // Arrange
-        var original = DocumentState.Create(Workspace.Services, _hostDocument, DocumentState.EmptyLoader)
+        var original = DocumentState.Create(_hostDocument, DocumentState.EmptyLoader)
             .WithTextLoader(_textLoader);
 
         await original.GetTextAsync();
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/GeneratedDocumentTextLoaderTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/GeneratedDocumentTextLoaderTest.cs
index bdcd2481ee..3d9ed06a0d 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/GeneratedDocumentTextLoaderTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/GeneratedDocumentTextLoaderTest.cs
@@ -5,6 +5,7 @@
 
 using System.Text;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common;
 using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.CodeAnalysis.Text;
@@ -30,7 +31,7 @@ public class GeneratedDocumentTextLoaderTest : WorkspaceTestBase
     {
         // Arrange
         var project = new ProjectSnapshot(
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, () => Task.FromResult(TextAndVersion.Create(SourceText.From(""), VersionStamp.Create()))));
 
         var document = project.GetDocument(_hostDocument.FilePath);
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs
index 31082046f7..bff0afc112 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateGeneratedOutputTest.cs
@@ -58,7 +58,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader);
 
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument);
@@ -77,7 +77,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader);
 
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument);
@@ -97,7 +97,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectImportFile, DocumentState.EmptyLoader);
 
@@ -119,7 +119,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectImportFile, DocumentState.EmptyLoader);
 
@@ -141,7 +141,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectImportFile, DocumentState.EmptyLoader);
 
@@ -162,12 +162,11 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
-            .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader)
-            .WithProjectWorkspaceState(ProjectWorkspaceState.Default);
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
+            .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader);
 
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument);
-        var changed = new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, csharpLanguageVersion: default);
+        var changed = ProjectWorkspaceState.Default;
 
         // Act
         var state = original.WithProjectWorkspaceState(changed);
@@ -176,7 +175,6 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
         var (actualOutput, actualInputVersion) = await GetOutputAsync(state, _hostDocument);
         Assert.Same(originalOutput, actualOutput);
         Assert.Equal(originalInputVersion, actualInputVersion);
-        Assert.Equal(state.ProjectWorkspaceStateVersion, actualInputVersion);
     }
 
     // The generated code's text doesn't change as a result, so the output version does not change
@@ -185,11 +183,11 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader);
 
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument);
-        var changed = new ProjectWorkspaceState(_someTagHelpers, default);
+        var changed = ProjectWorkspaceState.Create(_someTagHelpers);
 
         // Act
         var state = original.WithProjectWorkspaceState(changed);
@@ -207,11 +205,11 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
         // Arrange
         var csharp8ValidConfiguration = RazorConfiguration.Create(RazorLanguageVersion.Version_3_0, _hostProject.Configuration.ConfigurationName, _hostProject.Configuration.Extensions);
         var hostProject = new HostProject(TestProjectData.SomeProject.FilePath, TestProjectData.SomeProject.IntermediateOutputPath, csharp8ValidConfiguration, TestProjectData.SomeProject.RootNamespace);
-        var originalWorkspaceState = new ProjectWorkspaceState(_someTagHelpers, LanguageVersion.CSharp7);
+        var originalWorkspaceState = ProjectWorkspaceState.Create(_someTagHelpers, LanguageVersion.CSharp7);
         var original =
-            ProjectState.Create(Workspace.Services, hostProject, originalWorkspaceState)
+            ProjectState.Create(ProjectEngineFactory, hostProject, originalWorkspaceState)
             .WithAddedHostDocument(_hostDocument, () => Task.FromResult(TextAndVersion.Create(SourceText.From("@DateTime.Now"), VersionStamp.Default)));
-        var changedWorkspaceState = new ProjectWorkspaceState(_someTagHelpers, LanguageVersion.CSharp8);
+        var changedWorkspaceState = ProjectWorkspaceState.Create(_someTagHelpers, LanguageVersion.CSharp8);
 
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument);
 
@@ -230,7 +228,7 @@ public class ProjectStateGeneratedOutputTest : WorkspaceTestBase
     {
         // Arrange
         var original =
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, DocumentState.EmptyLoader);
 
         var (originalOutput, originalInputVersion) = await GetOutputAsync(original, _hostDocument);
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs
index b19250adf9..510c683044 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/ProjectSystem/ProjectStateTest.cs
@@ -1,11 +1,10 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
@@ -26,20 +25,21 @@ public class ProjectStateTest : WorkspaceTestBase
     private readonly HostProject _hostProject;
     private readonly HostProject _hostProjectWithConfigurationChange;
     private readonly ProjectWorkspaceState _projectWorkspaceState;
-    private TestTagHelperResolver _tagHelperResolver;
     private readonly ImmutableArray<TagHelperDescriptor> _someTagHelpers;
     private readonly Func<Task<TextAndVersion>> _textLoader;
     private readonly SourceText _text;
 
+    [AllowNull]
+    private TestTagHelperResolver _tagHelperResolver;
+
     public ProjectStateTest(ITestOutputHelper testOutput)
         : base(testOutput)
     {
         _hostProject = new HostProject(TestProjectData.SomeProject.FilePath, TestProjectData.SomeProject.IntermediateOutputPath, FallbackRazorConfiguration.MVC_2_0, TestProjectData.SomeProject.RootNamespace);
         _hostProjectWithConfigurationChange = new HostProject(TestProjectData.SomeProject.FilePath, TestProjectData.SomeProject.IntermediateOutputPath, FallbackRazorConfiguration.MVC_1_0, TestProjectData.SomeProject.RootNamespace);
-        _projectWorkspaceState = new ProjectWorkspaceState(
+        _projectWorkspaceState = ProjectWorkspaceState.Create(
             ImmutableArray.Create(
-                TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()),
-            csharpLanguageVersion: default);
+                TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()));
 
         _someTagHelpers = ImmutableArray.Create(
             TagHelperDescriptorBuilder.Create("Test1", "TestAssembly").Build());
@@ -72,7 +72,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void GetImportDocumentTargetPaths_DoesNotIncludeCurrentImport()
     {
         // Arrange
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
 
         // Act
         var paths = state.GetImportDocumentTargetPaths(TestProjectData.SomeProjectComponentImportFile1);
@@ -87,7 +87,7 @@ public class ProjectStateTest : WorkspaceTestBase
         // Arrange
 
         // Act
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
 
         // Assert
         Assert.Empty(state.Documents);
@@ -98,7 +98,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_AddHostDocument_ToEmpty()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
 
         // Act
         var state = original.WithAddedHostDocument(_documents[0], DocumentState.EmptyLoader);
@@ -116,7 +116,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public async Task ProjectState_AddHostDocument_DocumentIsEmpty()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
 
         // Act
         var state = original.WithAddedHostDocument(_documents[0], DocumentState.EmptyLoader);
@@ -130,7 +130,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_AddHostDocument_ToProjectWithDocuments()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -154,7 +154,7 @@ public class ProjectStateTest : WorkspaceTestBase
         // Arrange
 
         // Act
-        var state = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var state = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile1, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile2, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectNestedFile3, DocumentState.EmptyLoader)
@@ -193,7 +193,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_AddHostDocument_TracksImports_AddImportFile()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile1, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile2, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectNestedFile3, DocumentState.EmptyLoader)
@@ -236,7 +236,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_AddHostDocument_RetainsComputedState()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -269,7 +269,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_AddHostDocument_DuplicateNoops()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -284,7 +284,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public async Task ProjectState_WithChangedHostDocument_Loader()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -304,7 +304,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public async Task ProjectState_WithChangedHostDocument_Snapshot()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -324,7 +324,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithChangedHostDocument_Loader_RetainsComputedState()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -356,7 +356,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithChangedHostDocument_Snapshot_RetainsComputedState()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -388,7 +388,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithChangedHostDocument_Loader_NotFoundNoops()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -403,7 +403,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithChangedHostDocument_Snapshot_NotFoundNoops()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -418,7 +418,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_RemoveHostDocument_FromProjectWithDocuments()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -439,7 +439,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_RemoveHostDocument_TracksImports()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile1, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile2, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectNestedFile3, DocumentState.EmptyLoader)
@@ -479,7 +479,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_RemoveHostDocument_TracksImports_RemoveAllDocuments()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile1, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectFile2, DocumentState.EmptyLoader)
             .WithAddedHostDocument(TestProjectData.SomeProjectNestedFile3, DocumentState.EmptyLoader)
@@ -501,7 +501,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_RemoveHostDocument_RetainsComputedState()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -533,7 +533,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_RemoveHostDocument_NotFoundNoops()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -548,7 +548,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithHostProject_ConfigurationChange_UpdatesConfigurationState()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -588,7 +588,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithHostProject_RootNamespaceChange_UpdatesConfigurationState()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
         var hostProjectWithRootNamespaceChange = new HostProject(
@@ -614,7 +614,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithHostProject_NoConfigurationChange_Noops()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -635,10 +635,10 @@ public class ProjectStateTest : WorkspaceTestBase
         var callCount = 0;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[_documents[1].FilePath] = TestDocumentState.Create(Workspace.Services, _documents[1], onConfigurationChange: () => callCount++);
-        documents[_documents[2].FilePath] = TestDocumentState.Create(Workspace.Services, _documents[2], onConfigurationChange: () => callCount++);
+        documents[_documents[1].FilePath] = TestDocumentState.Create(_documents[1], onConfigurationChange: () => callCount++);
+        documents[_documents[2].FilePath] = TestDocumentState.Create(_documents[2], onConfigurationChange: () => callCount++);
 
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
 
         // Act
@@ -654,7 +654,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithHostProject_ResetsImportedDocuments()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original = original.WithAddedHostDocument(TestProjectData.SomeProjectFile1, DocumentState.EmptyLoader);
 
         // Act
@@ -666,87 +666,11 @@ public class ProjectStateTest : WorkspaceTestBase
         Assert.Equal(TestProjectData.SomeProjectFile1.FilePath, documentFilePath);
     }
 
-    [Fact]
-    public void ProjectState_WithProjectWorkspaceState_Removed()
-    {
-        // Arrange
-        var emptyProjectWorkspaceState = new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, csharpLanguageVersion: default);
-        var original = ProjectState.Create(Workspace.Services, _hostProject, emptyProjectWorkspaceState)
-            .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
-            .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
-
-        // Force init
-        var originalTagHelpers = original.TagHelpers;
-        var originalProjectWorkspaceStateVersion = original.ProjectWorkspaceStateVersion;
-
-        // Act
-        var state = original.WithProjectWorkspaceState(null);
-
-        // Assert
-        Assert.NotEqual(original.Version, state.Version);
-        Assert.Null(state.ProjectWorkspaceState);
-
-        var actualTagHelpers = state.TagHelpers;
-        var actualProjectWorkspaceStateVersion = state.ProjectWorkspaceStateVersion;
-
-        // The configuration didn't change, and the tag helpers didn't actually change
-        Assert.Same(original.ProjectEngine, state.ProjectEngine);
-
-        Assert.Equal(originalTagHelpers.Length, actualTagHelpers.Length);
-        for (var i = 0; i < originalTagHelpers.Length; i++)
-        {
-            Assert.Same(originalTagHelpers[i], actualTagHelpers[i]);
-        }
-
-        Assert.NotEqual(originalProjectWorkspaceStateVersion, actualProjectWorkspaceStateVersion);
-
-        Assert.NotSame(original.Documents[_documents[1].FilePath], state.Documents[_documents[1].FilePath]);
-        Assert.NotSame(original.Documents[_documents[2].FilePath], state.Documents[_documents[2].FilePath]);
-    }
-
-    [Fact]
-    public void ProjectState_WithProjectWorkspaceState_Added()
-    {
-        // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, null)
-            .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
-            .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
-
-        // Force init
-        var originalTagHelpers = original.TagHelpers;
-        var originalProjectWorkspaceStateVersion = original.ProjectWorkspaceStateVersion;
-        var newProjectWorkspaceState = ProjectWorkspaceState.Default;
-
-        // Act
-        var state = original.WithProjectWorkspaceState(newProjectWorkspaceState);
-
-        // Assert
-        Assert.NotEqual(original.Version, state.Version);
-        Assert.Same(newProjectWorkspaceState, state.ProjectWorkspaceState);
-
-        var actualTagHelpers = state.TagHelpers;
-        var actualProjectWorkspaceStateVersion = state.ProjectWorkspaceStateVersion;
-
-        // The configuration didn't change, and the tag helpers didn't actually change
-        Assert.Same(original.ProjectEngine, state.ProjectEngine);
-
-        Assert.Equal(originalTagHelpers.Length, actualTagHelpers.Length);
-        for (var i = 0; i < originalTagHelpers.Length; i++)
-        {
-            Assert.Same(originalTagHelpers[i], actualTagHelpers[i]);
-        }
-
-        Assert.NotEqual(originalProjectWorkspaceStateVersion, actualProjectWorkspaceStateVersion);
-
-        Assert.NotSame(original.Documents[_documents[1].FilePath], state.Documents[_documents[1].FilePath]);
-        Assert.NotSame(original.Documents[_documents[1].FilePath], state.Documents[_documents[1].FilePath]);
-    }
-
     [Fact]
     public void ProjectState_WithProjectWorkspaceState_Changed()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -754,7 +678,7 @@ public class ProjectStateTest : WorkspaceTestBase
         var originalTagHelpers = original.TagHelpers;
         var originalProjectWorkspaceStateVersion = original.ProjectWorkspaceStateVersion;
 
-        var changed = new ProjectWorkspaceState(_projectWorkspaceState.TagHelpers, LanguageVersion.CSharp6);
+        var changed = ProjectWorkspaceState.Create(_projectWorkspaceState.TagHelpers, LanguageVersion.CSharp6);
 
         // Act
         var state = original.WithProjectWorkspaceState(changed);
@@ -785,7 +709,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithProjectWorkspaceState_Changed_TagHelpersChanged()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -793,7 +717,7 @@ public class ProjectStateTest : WorkspaceTestBase
         var originalTagHelpers = original.TagHelpers;
         var originalProjectWorkspaceStateVersion = original.ProjectWorkspaceStateVersion;
 
-        var changed = new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, csharpLanguageVersion: default);
+        var changed = ProjectWorkspaceState.Default;
 
         // Now create some tag helpers
         _tagHelperResolver.TagHelpers = _someTagHelpers;
@@ -822,7 +746,7 @@ public class ProjectStateTest : WorkspaceTestBase
     public void ProjectState_WithProjectWorkspaceState_IdenticalState_Caches()
     {
         // Arrange
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState)
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState)
             .WithAddedHostDocument(_documents[2], DocumentState.EmptyLoader)
             .WithAddedHostDocument(_documents[1], DocumentState.EmptyLoader);
 
@@ -830,7 +754,7 @@ public class ProjectStateTest : WorkspaceTestBase
         _ = original.TagHelpers;
         _ = original.ProjectWorkspaceStateVersion;
 
-        var changed = new ProjectWorkspaceState(original.TagHelpers, original.CSharpLanguageVersion);
+        var changed = ProjectWorkspaceState.Create(original.TagHelpers, original.CSharpLanguageVersion);
 
         // Now create some tag helpers
         _tagHelperResolver.TagHelpers = _someTagHelpers;
@@ -849,13 +773,13 @@ public class ProjectStateTest : WorkspaceTestBase
         var callCount = 0;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[_documents[1].FilePath] = TestDocumentState.Create(Workspace.Services, _documents[1], onProjectWorkspaceStateChange: () => callCount++);
-        documents[_documents[2].FilePath] = TestDocumentState.Create(Workspace.Services, _documents[2], onProjectWorkspaceStateChange: () => callCount++);
+        documents[_documents[1].FilePath] = TestDocumentState.Create(_documents[1], onProjectWorkspaceStateChange: () => callCount++);
+        documents[_documents[2].FilePath] = TestDocumentState.Create(_documents[2], onProjectWorkspaceStateChange: () => callCount++);
 
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
 
-        var changed = new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, csharpLanguageVersion: default);
+        var changed = ProjectWorkspaceState.Default;
 
         // Act
         var state = original.WithProjectWorkspaceState(changed);
@@ -877,10 +801,10 @@ public class ProjectStateTest : WorkspaceTestBase
         var document4 = TestProjectData.AnotherProjectNestedFile4;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[document1.FilePath] = TestDocumentState.Create(Workspace.Services, document1, onImportsChange: () => callCount++);
-        documents[document2.FilePath] = TestDocumentState.Create(Workspace.Services, document2, onImportsChange: () => callCount++);
-        documents[document3.FilePath] = TestDocumentState.Create(Workspace.Services, document3, onImportsChange: () => callCount++);
-        documents[document4.FilePath] = TestDocumentState.Create(Workspace.Services, document4, onImportsChange: () => callCount++);
+        documents[document1.FilePath] = TestDocumentState.Create(document1, onImportsChange: () => callCount++);
+        documents[document2.FilePath] = TestDocumentState.Create(document2, onImportsChange: () => callCount++);
+        documents[document3.FilePath] = TestDocumentState.Create(document3, onImportsChange: () => callCount++);
+        documents[document4.FilePath] = TestDocumentState.Create(document4, onImportsChange: () => callCount++);
 
         var importsToRelatedDocuments = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(FilePathComparer.Instance);
         importsToRelatedDocuments.Add(
@@ -896,7 +820,7 @@ public class ProjectStateTest : WorkspaceTestBase
                 TestProjectData.SomeProjectNestedFile3.FilePath,
                 TestProjectData.AnotherProjectNestedFile4.FilePath));
 
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
         original.ImportsToRelatedDocuments = importsToRelatedDocuments.ToImmutable();
 
@@ -920,10 +844,10 @@ public class ProjectStateTest : WorkspaceTestBase
         var document4 = TestProjectData.AnotherProjectNestedFile4;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[document1.FilePath] = TestDocumentState.Create(Workspace.Services, document1, onImportsChange: () => callCount++);
-        documents[document2.FilePath] = TestDocumentState.Create(Workspace.Services, document2, onImportsChange: () => callCount++);
-        documents[document3.FilePath] = TestDocumentState.Create(Workspace.Services, document3, onImportsChange: () => callCount++);
-        documents[document4.FilePath] = TestDocumentState.Create(Workspace.Services, document4, onImportsChange: () => callCount++);
+        documents[document1.FilePath] = TestDocumentState.Create(document1, onImportsChange: () => callCount++);
+        documents[document2.FilePath] = TestDocumentState.Create(document2, onImportsChange: () => callCount++);
+        documents[document3.FilePath] = TestDocumentState.Create(document3, onImportsChange: () => callCount++);
+        documents[document4.FilePath] = TestDocumentState.Create(document4, onImportsChange: () => callCount++);
 
         var importsToRelatedDocuments = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(FilePathComparer.Instance);
         importsToRelatedDocuments.Add(
@@ -939,7 +863,7 @@ public class ProjectStateTest : WorkspaceTestBase
                 TestProjectData.SomeProjectNestedFile3.FilePath,
                 TestProjectData.AnotherProjectNestedFile4.FilePath));
 
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
         original.ImportsToRelatedDocuments = importsToRelatedDocuments.ToImmutable();
 
@@ -964,11 +888,11 @@ public class ProjectStateTest : WorkspaceTestBase
         var document5 = TestProjectData.AnotherProjectNestedImportFile;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[document1.FilePath] = TestDocumentState.Create(Workspace.Services, document1, onImportsChange: () => callCount++);
-        documents[document2.FilePath] = TestDocumentState.Create(Workspace.Services, document2, onImportsChange: () => callCount++);
-        documents[document3.FilePath] = TestDocumentState.Create(Workspace.Services, document3, onImportsChange: () => callCount++);
-        documents[document4.FilePath] = TestDocumentState.Create(Workspace.Services, document4, onImportsChange: () => callCount++);
-        documents[document5.FilePath] = TestDocumentState.Create(Workspace.Services, document5, onImportsChange: () => callCount++);
+        documents[document1.FilePath] = TestDocumentState.Create(document1, onImportsChange: () => callCount++);
+        documents[document2.FilePath] = TestDocumentState.Create(document2, onImportsChange: () => callCount++);
+        documents[document3.FilePath] = TestDocumentState.Create(document3, onImportsChange: () => callCount++);
+        documents[document4.FilePath] = TestDocumentState.Create(document4, onImportsChange: () => callCount++);
+        documents[document5.FilePath] = TestDocumentState.Create(document5, onImportsChange: () => callCount++);
 
         var importsToRelatedDocuments = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(FilePathComparer.Instance);
         importsToRelatedDocuments.Add(
@@ -985,7 +909,7 @@ public class ProjectStateTest : WorkspaceTestBase
                 TestProjectData.SomeProjectNestedFile3.FilePath,
                 TestProjectData.AnotherProjectNestedFile4.FilePath));
 
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
         original.ImportsToRelatedDocuments = importsToRelatedDocuments.ToImmutable();
 
@@ -1010,11 +934,11 @@ public class ProjectStateTest : WorkspaceTestBase
         var document5 = TestProjectData.AnotherProjectNestedImportFile;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[document1.FilePath] = TestDocumentState.Create(Workspace.Services, document1, onImportsChange: () => callCount++);
-        documents[document2.FilePath] = TestDocumentState.Create(Workspace.Services, document2, onImportsChange: () => callCount++);
-        documents[document3.FilePath] = TestDocumentState.Create(Workspace.Services, document3, onImportsChange: () => callCount++);
-        documents[document4.FilePath] = TestDocumentState.Create(Workspace.Services, document4, onImportsChange: () => callCount++);
-        documents[document5.FilePath] = TestDocumentState.Create(Workspace.Services, document5, onImportsChange: () => callCount++);
+        documents[document1.FilePath] = TestDocumentState.Create(document1, onImportsChange: () => callCount++);
+        documents[document2.FilePath] = TestDocumentState.Create(document2, onImportsChange: () => callCount++);
+        documents[document3.FilePath] = TestDocumentState.Create(document3, onImportsChange: () => callCount++);
+        documents[document4.FilePath] = TestDocumentState.Create(document4, onImportsChange: () => callCount++);
+        documents[document5.FilePath] = TestDocumentState.Create(document5, onImportsChange: () => callCount++);
 
         var importsToRelatedDocuments = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(FilePathComparer.Instance);
         importsToRelatedDocuments.Add(
@@ -1031,7 +955,7 @@ public class ProjectStateTest : WorkspaceTestBase
                 TestProjectData.SomeProjectNestedFile3.FilePath,
                 TestProjectData.AnotherProjectNestedFile4.FilePath));
 
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
         original.ImportsToRelatedDocuments = importsToRelatedDocuments.ToImmutable();
 
@@ -1056,11 +980,11 @@ public class ProjectStateTest : WorkspaceTestBase
         var document5 = TestProjectData.AnotherProjectNestedImportFile;
 
         var documents = ImmutableDictionary.CreateBuilder<string, DocumentState>(FilePathComparer.Instance);
-        documents[document1.FilePath] = TestDocumentState.Create(Workspace.Services, document1, onImportsChange: () => callCount++);
-        documents[document2.FilePath] = TestDocumentState.Create(Workspace.Services, document2, onImportsChange: () => callCount++);
-        documents[document3.FilePath] = TestDocumentState.Create(Workspace.Services, document3, onImportsChange: () => callCount++);
-        documents[document4.FilePath] = TestDocumentState.Create(Workspace.Services, document4, onImportsChange: () => callCount++);
-        documents[document5.FilePath] = TestDocumentState.Create(Workspace.Services, document5, onImportsChange: () => callCount++);
+        documents[document1.FilePath] = TestDocumentState.Create(document1, onImportsChange: () => callCount++);
+        documents[document2.FilePath] = TestDocumentState.Create(document2, onImportsChange: () => callCount++);
+        documents[document3.FilePath] = TestDocumentState.Create(document3, onImportsChange: () => callCount++);
+        documents[document4.FilePath] = TestDocumentState.Create(document4, onImportsChange: () => callCount++);
+        documents[document5.FilePath] = TestDocumentState.Create(document5, onImportsChange: () => callCount++);
 
         var importsToRelatedDocuments = ImmutableDictionary.CreateBuilder<string, ImmutableArray<string>>(FilePathComparer.Instance);
         importsToRelatedDocuments.Add(
@@ -1077,7 +1001,7 @@ public class ProjectStateTest : WorkspaceTestBase
                 TestProjectData.SomeProjectNestedFile3.FilePath,
                 TestProjectData.AnotherProjectNestedFile4.FilePath));
 
-        var original = ProjectState.Create(Workspace.Services, _hostProject, _projectWorkspaceState);
+        var original = ProjectState.Create(ProjectEngineFactory, _hostProject, _projectWorkspaceState);
         original.Documents = documents.ToImmutable();
         original.ImportsToRelatedDocuments = importsToRelatedDocuments.ToImmutable();
 
@@ -1092,17 +1016,15 @@ public class ProjectStateTest : WorkspaceTestBase
     private class TestDocumentState : DocumentState
     {
         public static TestDocumentState Create(
-            HostWorkspaceServices services,
             HostDocument hostDocument,
-            Func<Task<TextAndVersion>> loader = null,
-            Action onTextChange = null,
-            Action onTextLoaderChange = null,
-            Action onConfigurationChange = null,
-            Action onImportsChange = null,
-            Action onProjectWorkspaceStateChange = null)
+            Func<Task<TextAndVersion>>? loader = null,
+            Action? onTextChange = null,
+            Action? onTextLoaderChange = null,
+            Action? onConfigurationChange = null,
+            Action? onImportsChange = null,
+            Action? onProjectWorkspaceStateChange = null)
         {
             return new TestDocumentState(
-                services,
                 hostDocument,
                 null,
                 null,
@@ -1114,24 +1036,23 @@ public class ProjectStateTest : WorkspaceTestBase
                 onProjectWorkspaceStateChange);
         }
 
-        private readonly Action _onTextChange;
-        private readonly Action _onTextLoaderChange;
-        private readonly Action _onConfigurationChange;
-        private readonly Action _onImportsChange;
-        private readonly Action _onProjectWorkspaceStateChange;
+        private readonly Action? _onTextChange;
+        private readonly Action? _onTextLoaderChange;
+        private readonly Action? _onConfigurationChange;
+        private readonly Action? _onImportsChange;
+        private readonly Action? _onProjectWorkspaceStateChange;
 
         private TestDocumentState(
-            HostWorkspaceServices services,
             HostDocument hostDocument,
-            SourceText text,
+            SourceText? text,
             VersionStamp? version,
-            Func<Task<TextAndVersion>> loader,
-            Action onTextChange,
-            Action onTextLoaderChange,
-            Action onConfigurationChange,
-            Action onImportsChange,
-            Action onProjectWorkspaceStateChange)
-            : base(services, hostDocument, text, version, loader)
+            Func<Task<TextAndVersion>>? loader,
+            Action? onTextChange,
+            Action? onTextLoaderChange,
+            Action? onConfigurationChange,
+            Action? onImportsChange,
+            Action? onProjectWorkspaceStateChange)
+            : base(hostDocument, text, version, loader)
         {
             _onTextChange = onTextChange;
             _onTextLoaderChange = onTextLoaderChange;
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/RazorSpanMappingServiceTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/RazorSpanMappingServiceTest.cs
index 03a314ee66..d31c67776e 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/RazorSpanMappingServiceTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/RazorSpanMappingServiceTest.cs
@@ -7,6 +7,7 @@ using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
+using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common;
 using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.CodeAnalysis.Host;
@@ -36,7 +37,7 @@ public class RazorSpanMappingServiceTest(ITestOutputHelper testOutput) : Workspa
 ");
 
         var project = new ProjectSnapshot(
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, () => Task.FromResult(TextAndVersion.Create(sourceText, VersionStamp.Create()))));
 
         var document = project.GetDocument(_hostDocument.FilePath);
@@ -68,7 +69,7 @@ public class RazorSpanMappingServiceTest(ITestOutputHelper testOutput) : Workspa
 ");
 
         var project = new ProjectSnapshot(
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, () => Task.FromResult(TextAndVersion.Create(sourceText, VersionStamp.Create()))));
 
         var document = project.GetDocument(_hostDocument.FilePath);
@@ -101,7 +102,7 @@ public class RazorSpanMappingServiceTest(ITestOutputHelper testOutput) : Workspa
 ");
 
         var project = new ProjectSnapshot(
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, () => Task.FromResult(TextAndVersion.Create(sourceText, VersionStamp.Create()))));
 
         var document = project.GetDocument(_hostDocument.FilePath);
@@ -133,7 +134,7 @@ public class RazorSpanMappingServiceTest(ITestOutputHelper testOutput) : Workspa
 ");
 
         var project = new ProjectSnapshot(
-            ProjectState.Create(Workspace.Services, _hostProject)
+            ProjectState.Create(ProjectEngineFactory, _hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(_hostDocument, () => Task.FromResult(TextAndVersion.Create(sourceText, VersionStamp.Create()))));
 
         var document = project.GetDocument(_hostDocument.FilePath);
diff --git a/src/Razor/test/Microsoft.CodeAnalysis.Remote.Razor.Test/OOPTagHelperResolverTest.cs b/src/Razor/test/Microsoft.CodeAnalysis.Remote.Razor.Test/OOPTagHelperResolverTest.cs
index 0d50f59c2e..caa2fd9459 100644
--- a/src/Razor/test/Microsoft.CodeAnalysis.Remote.Razor.Test/OOPTagHelperResolverTest.cs
+++ b/src/Razor/test/Microsoft.CodeAnalysis.Remote.Razor.Test/OOPTagHelperResolverTest.cs
@@ -10,6 +10,7 @@ using Microsoft.AspNetCore.Razor;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Serialization;
 using Microsoft.AspNetCore.Razor.Telemetry;
+using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.AspNetCore.Razor.Utilities;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -24,7 +25,6 @@ public partial class OOPTagHelperResolverTest : TagHelperDescriptorTestBase
 {
     private readonly ProjectSnapshotProjectEngineFactory _engineFactory;
     private readonly Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>[] _customFactories;
-    private readonly IFallbackProjectEngineFactory _fallbackFactory;
     private readonly HostProject _hostProject_For_2_0;
     private readonly HostProject _hostProject_For_NonSerializableConfiguration;
     private readonly ProjectSnapshotManagerBase _projectManager;
@@ -37,10 +37,10 @@ public partial class OOPTagHelperResolverTest : TagHelperDescriptorTestBase
         _hostProject_For_2_0 = new HostProject("Test.csproj", "/obj", FallbackRazorConfiguration.MVC_2_0, rootNamespace: null);
         _hostProject_For_NonSerializableConfiguration = new HostProject(
             "Test.csproj", "/obj",
-            new ProjectSystemRazorConfiguration(RazorLanguageVersion.Version_2_1, "Random-0.1", Array.Empty<RazorExtension>()), rootNamespace: null);
+            new ProjectSystemRazorConfiguration(RazorLanguageVersion.Version_2_1, "Random-0.1", []), rootNamespace: null);
 
-        _customFactories = new Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>[]
-        {
+        _customFactories =
+        [
             new Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>(
                 () => Mock.Of<IProjectEngineFactory>(MockBehavior.Strict),
                 new ExportCustomProjectEngineFactoryAttribute("MVC-2.0") { SupportsSerialization = true, }),
@@ -49,18 +49,20 @@ public partial class OOPTagHelperResolverTest : TagHelperDescriptorTestBase
             new Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>(
                 () => Mock.Of<IProjectEngineFactory>(MockBehavior.Strict),
                 new ExportCustomProjectEngineFactoryAttribute("Test-2") { SupportsSerialization = false, }),
-        };
+        ];
 
-        _fallbackFactory = new FallbackProjectEngineFactory();
+        var fallbackFactory = new FallbackProjectEngineFactory();
 
-        _workspace = new AdhocWorkspace();
+        _engineFactory = new DefaultProjectSnapshotProjectEngineFactory(fallbackFactory, _customFactories);
+        var testServices = TestServices.Create([_engineFactory], []);
+
+        _workspace = new AdhocWorkspace(testServices);
         AddDisposable(_workspace);
 
         var info = ProjectInfo.Create(ProjectId.CreateNewId("Test"), VersionStamp.Default, "Test", "Test", LanguageNames.CSharp, filePath: "Test.csproj");
         _workspaceProject = _workspace.CurrentSolution.AddProject(info).GetProject(info.Id).AssumeNotNull();
 
         _projectManager = new TestProjectSnapshotManager(_workspace);
-        _engineFactory = new DefaultProjectSnapshotProjectEngineFactory(_fallbackFactory, _customFactories);
     }
 
     [Fact]
diff --git a/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectSnapshotProjectEngineFactoryTest.cs b/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectSnapshotProjectEngineFactoryTest.cs
index 7a33f382e3..ec7da7d786 100644
--- a/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectSnapshotProjectEngineFactoryTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectSnapshotProjectEngineFactoryTest.cs
@@ -8,9 +8,9 @@ using System.Reflection;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common;
-using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 using Microsoft.CodeAnalysis.Razor.Workspaces;
+using Moq;
 using Xunit;
 using Xunit.Abstractions;
 using Mvc1_X = Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X;
@@ -24,56 +24,45 @@ public class DefaultProjectSnapshotProjectEngineFactoryTest : ToolingTestBase
 {
     private readonly Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>[] _customFactories;
     private readonly IFallbackProjectEngineFactory _fallbackFactory;
-    private readonly HostProject _hostProject_For_1_0;
-    private readonly HostProject _hostProject_For_1_1;
-    private readonly HostProject _hostProject_For_2_0;
-    private readonly HostProject _hostProject_For_2_1;
-    private readonly HostProject _hostProject_For_3_0;
-    private readonly HostProject _hostProject_For_UnknownConfiguration;
     private readonly IProjectSnapshot _snapshot_For_1_0;
     private readonly IProjectSnapshot _snapshot_For_1_1;
     private readonly IProjectSnapshot _snapshot_For_2_0;
     private readonly IProjectSnapshot _snapshot_For_2_1;
     private readonly IProjectSnapshot _snapshot_For_3_0;
     private readonly IProjectSnapshot _snapshot_For_UnknownConfiguration;
-    private readonly ProjectWorkspaceState _projectWorkspaceState;
-    private readonly Workspace _workspace;
 
     public DefaultProjectSnapshotProjectEngineFactoryTest(ITestOutputHelper testOutput)
         : base(testOutput)
     {
-        _workspace = TestWorkspace.Create();
-        AddDisposable(_workspace);
-
-        _projectWorkspaceState = ProjectWorkspaceState.Default;
-
         var projectFilePath = "/TestPath/SomePath/Test.csproj";
         var intermediateOutputPath = "/TestPath/SomePath/obj";
-        _hostProject_For_1_0 = new HostProject(projectFilePath, intermediateOutputPath, FallbackRazorConfiguration.MVC_1_0, "Test");
-        _hostProject_For_1_1 = new HostProject(projectFilePath, intermediateOutputPath, FallbackRazorConfiguration.MVC_1_1, "Test");
-        _hostProject_For_2_0 = new HostProject(projectFilePath, intermediateOutputPath, FallbackRazorConfiguration.MVC_2_0, "Test");
+        var hostProject_For_1_0 = new HostProject(projectFilePath, intermediateOutputPath, FallbackRazorConfiguration.MVC_1_0, "Test");
+        var hostProject_For_1_1 = new HostProject(projectFilePath, intermediateOutputPath, FallbackRazorConfiguration.MVC_1_1, "Test");
+        var hostProject_For_2_0 = new HostProject(projectFilePath, intermediateOutputPath, FallbackRazorConfiguration.MVC_2_0, "Test");
 
-        _hostProject_For_2_1 = new HostProject(
+        var hostProject_For_2_1 = new HostProject(
             projectFilePath, intermediateOutputPath,
             new ProjectSystemRazorConfiguration(RazorLanguageVersion.Version_2_1, "MVC-2.1", Array.Empty<RazorExtension>()), "Test");
 
-        _hostProject_For_3_0 = new HostProject(
+        var hostProject_For_3_0 = new HostProject(
             projectFilePath, intermediateOutputPath,
             new ProjectSystemRazorConfiguration(RazorLanguageVersion.Version_3_0, "MVC-3.0", Array.Empty<RazorExtension>()), "Test");
 
-        _hostProject_For_UnknownConfiguration = new HostProject(
+        var hostProject_For_UnknownConfiguration = new HostProject(
             projectFilePath, intermediateOutputPath,
             new ProjectSystemRazorConfiguration(RazorLanguageVersion.Version_2_1, "Random-0.1", Array.Empty<RazorExtension>()), rootNamespace: null);
 
-        _snapshot_For_1_0 = new ProjectSnapshot(ProjectState.Create(_workspace.Services, _hostProject_For_1_0, _projectWorkspaceState));
-        _snapshot_For_1_1 = new ProjectSnapshot(ProjectState.Create(_workspace.Services, _hostProject_For_1_1, _projectWorkspaceState));
-        _snapshot_For_2_0 = new ProjectSnapshot(ProjectState.Create(_workspace.Services, _hostProject_For_2_0, _projectWorkspaceState));
-        _snapshot_For_2_1 = new ProjectSnapshot(ProjectState.Create(_workspace.Services, _hostProject_For_2_1, _projectWorkspaceState));
-        _snapshot_For_3_0 = new ProjectSnapshot(ProjectState.Create(_workspace.Services, _hostProject_For_3_0, _projectWorkspaceState));
-        _snapshot_For_UnknownConfiguration = new ProjectSnapshot(ProjectState.Create(_workspace.Services, _hostProject_For_UnknownConfiguration, _projectWorkspaceState));
+        var projectEngineFactory = Mock.Of<ProjectSnapshotProjectEngineFactory>(MockBehavior.Strict);
 
-        _customFactories = new Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>[]
-        {
+        _snapshot_For_1_0 = new ProjectSnapshot(ProjectState.Create(projectEngineFactory, hostProject_For_1_0, ProjectWorkspaceState.Default));
+        _snapshot_For_1_1 = new ProjectSnapshot(ProjectState.Create(projectEngineFactory, hostProject_For_1_1, ProjectWorkspaceState.Default));
+        _snapshot_For_2_0 = new ProjectSnapshot(ProjectState.Create(projectEngineFactory, hostProject_For_2_0, ProjectWorkspaceState.Default));
+        _snapshot_For_2_1 = new ProjectSnapshot(ProjectState.Create(projectEngineFactory, hostProject_For_2_1, ProjectWorkspaceState.Default));
+        _snapshot_For_3_0 = new ProjectSnapshot(ProjectState.Create(projectEngineFactory, hostProject_For_3_0, ProjectWorkspaceState.Default));
+        _snapshot_For_UnknownConfiguration = new ProjectSnapshot(ProjectState.Create(projectEngineFactory, hostProject_For_UnknownConfiguration, ProjectWorkspaceState.Default));
+
+        _customFactories =
+        [
             new Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>(
                 () => new LegacyProjectEngineFactory_1_0(),
                 typeof(LegacyProjectEngineFactory_1_0).GetCustomAttribute<ExportCustomProjectEngineFactoryAttribute>()),
@@ -89,7 +78,7 @@ public class DefaultProjectSnapshotProjectEngineFactoryTest : ToolingTestBase
             new Lazy<IProjectEngineFactory, ICustomProjectEngineFactoryMetadata>(
                 () => new LegacyProjectEngineFactory_3_0(),
                 typeof(LegacyProjectEngineFactory_3_0).GetCustomAttribute<ExportCustomProjectEngineFactoryAttribute>()),
-        };
+        ];
 
         _fallbackFactory = new FallbackProjectEngineFactory();
     }
diff --git a/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectWorkspaceStateGeneratorTest.cs b/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectWorkspaceStateGeneratorTest.cs
index 4397bc3670..30ebb3ffce 100644
--- a/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectWorkspaceStateGeneratorTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.Editor.Razor.Test/DefaultProjectWorkspaceStateGeneratorTest.cs
@@ -18,6 +18,7 @@ using Microsoft.AspNetCore.Razor.Test.Common.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.CodeAnalysis.Host;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
+using Moq;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -34,13 +35,15 @@ public class DefaultProjectWorkspaceStateGeneratorTest : ProjectSnapshotManagerD
     public DefaultProjectWorkspaceStateGeneratorTest(ITestOutputHelper testOutput)
         : base(testOutput)
     {
+        var projectEngineFactory = Mock.Of<ProjectSnapshotProjectEngineFactory>(MockBehavior.Strict);
+
         var tagHelperResolver = new TestTagHelperResolver()
         {
             TagHelpers = ImmutableArray.Create(TagHelperDescriptorBuilder.Create("ResolvableTagHelper", "TestAssembly").Build())
         };
 
         _resolvableTagHelpers = tagHelperResolver.TagHelpers;
-        var workspaceServices = new List<IWorkspaceService>() { tagHelperResolver };
+        var workspaceServices = new List<IWorkspaceService>() { tagHelperResolver, projectEngineFactory };
         var testServices = TestServices.Create(workspaceServices, Enumerable.Empty<ILanguageService>());
         _workspace = TestWorkspace.Create(testServices);
         AddDisposable(_workspace);
@@ -53,10 +56,10 @@ public class DefaultProjectWorkspaceStateGeneratorTest : ProjectSnapshotManagerD
             LanguageNames.CSharp,
             TestProjectData.SomeProject.FilePath));
         _workspaceProject = solution.GetProject(projectId);
-        _projectSnapshot = new ProjectSnapshot(ProjectState.Create(_workspace.Services, TestProjectData.SomeProject));
-        _projectWorkspaceStateWithTagHelpers = new ProjectWorkspaceState(ImmutableArray.Create(
-            TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()),
-            csharpLanguageVersion: default);
+        _projectSnapshot = new ProjectSnapshot(
+            ProjectState.Create(projectEngineFactory, TestProjectData.SomeProject, ProjectWorkspaceState.Default));
+        _projectWorkspaceStateWithTagHelpers = ProjectWorkspaceState.Create(ImmutableArray.Create(
+            TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()));
     }
 
     [UIFact]
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorDocumentOptionsServiceTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorDocumentOptionsServiceTest.cs
index a3c557c287..041cd69492 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorDocumentOptionsServiceTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorDocumentOptionsServiceTest.cs
@@ -9,6 +9,7 @@ using System.Linq;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
+using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Formatting;
@@ -103,7 +104,7 @@ public class RazorDocumentOptionsServiceTest : WorkspaceTestBase
             Path.Combine(baseDirectory, "SomeProject", "File1.cshtml"), "File1.cshtml", FileKinds.Legacy);
 
         var project = new ProjectSnapshot(
-            ProjectState.Create(Workspace.Services, hostProject)
+            ProjectState.Create(ProjectEngineFactory, hostProject, ProjectWorkspaceState.Default)
             .WithAddedHostDocument(hostDocument, () => Task.FromResult(TextAndVersion.Create(sourceText, VersionStamp.Create()))));
 
         var documentSnapshot = project.GetDocument(hostDocument.FilePath);
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorProjectInfoPublisherTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorProjectInfoPublisherTest.cs
index 80a6cdbad7..94394652ef 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorProjectInfoPublisherTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/RazorProjectInfoPublisherTest.cs
@@ -36,8 +36,8 @@ public class RazorProjectInfoPublisherTest(ITestOutputHelper testOutput) : Langu
             new TagHelperDescriptor(FileKinds.Component, "Namespace.FileNameOther", "Assembly", "FileName", "FileName document", "FileName hint",
                 caseSensitive: false, tagMatchingRules: default, attributeDescriptors: default, allowedChildTags: default, metadata: null, diagnostics: default));
 
-        var initialProjectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", new ProjectWorkspaceState(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.Preview));
-        var expectedProjectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, CodeAnalysis.CSharp.LanguageVersion.Preview));
+        var initialProjectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", ProjectWorkspaceState.Create(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.Preview));
+        var expectedProjectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", ProjectWorkspaceState.Create(CodeAnalysis.CSharp.LanguageVersion.Preview));
         var expectedConfigurationFilePath = @"C:\path\to\obj\bin\Debug\project.razor.bin";
         var publisher = new TestRazorProjectInfoPublisher(
             projectConfigurationFilePathStore,
@@ -220,7 +220,7 @@ public class RazorProjectInfoPublisherTest(ITestOutputHelper testOutput) : Langu
         var projectConfigurationFilePathStore = new DefaultProjectConfigurationFilePathStore();
 
         var serializationSuccessful = false;
-        var projectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, CodeAnalysis.CSharp.LanguageVersion.CSharp7_3));
+        var projectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", ProjectWorkspaceState.Create(CodeAnalysis.CSharp.LanguageVersion.CSharp7_3));
         var expectedConfigurationFilePath = @"C:\path\to\obj\bin\Debug\project.razor.bin";
         var publisher = new TestRazorProjectInfoPublisher(
             projectConfigurationFilePathStore,
@@ -255,8 +255,8 @@ public class RazorProjectInfoPublisherTest(ITestOutputHelper testOutput) : Langu
         var projectConfigurationFilePathStore = new DefaultProjectConfigurationFilePathStore();
 
         var serializationSuccessful = false;
-        var projectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, CodeAnalysis.CSharp.LanguageVersion.Default));
-        var changedProjectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, CodeAnalysis.CSharp.LanguageVersion.CSharp8));
+        var projectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", ProjectWorkspaceState.Default);
+        var changedProjectSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", ProjectWorkspaceState.Create(CodeAnalysis.CSharp.LanguageVersion.CSharp8));
         var expectedConfigurationFilePath = @"C:\path\to\obj\bin\Debug\project.razor.bin";
         var aboutToChange = false;
         var publisher = new TestRazorProjectInfoPublisher(
@@ -414,9 +414,10 @@ public class RazorProjectInfoPublisherTest(ITestOutputHelper testOutput) : Langu
             new TagHelperDescriptor(FileKinds.Component, "Namespace.FileNameOther", "Assembly", "FileName", "FileName document", "FileName hint",
                 caseSensitive: false, tagMatchingRules: default, attributeDescriptors: default, allowedChildTags: default, metadata: null, diagnostics: default));
 
-        var secondSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", new ProjectWorkspaceState(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.CSharp8), new string[]{
+        var secondSnapshot = CreateProjectSnapshot(@"C:\path\to\project.csproj", ProjectWorkspaceState.Create(tagHelpers, CodeAnalysis.CSharp.LanguageVersion.CSharp8),
+        [
             "FileName.razor"
-        });
+        ]);
         var expectedConfigurationFilePath = @"C:\path\to\obj\bin\Debug\project.razor.bin";
         var publisher = new TestRazorProjectInfoPublisher(
             projectConfigurationFilePathStore,
@@ -517,7 +518,7 @@ public class RazorProjectInfoPublisherTest(ITestOutputHelper testOutput) : Langu
         var projectFilePath = @"C:\path\to\project.csproj";
         var hostProject = new HostProject(projectFilePath, Path.Combine(Path.GetDirectoryName(projectFilePath), "obj"), RazorConfiguration.Default, "TestRootNamespace");
         projectConfigurationFilePathStore.Set(hostProject.Key, expectedConfigurationFilePath);
-        var projectWorkspaceState = new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, CodeAnalysis.CSharp.LanguageVersion.Default);
+        var projectWorkspaceState = ProjectWorkspaceState.Default;
 
         // Act
         await RunOnDispatcherThreadAsync(() =>
@@ -610,7 +611,7 @@ public class RazorProjectInfoPublisherTest(ITestOutputHelper testOutput) : Langu
         var projectFilePath = @"C:\path\to\project.csproj";
         var hostProject = new HostProject(projectFilePath, Path.Combine(Path.GetDirectoryName(projectFilePath), "obj"), RazorConfiguration.Default, "TestRootNamespace");
         projectConfigurationFilePathStore.Set(hostProject.Key, expectedConfigurationFilePath);
-        var projectWorkspaceState = new ProjectWorkspaceState(ImmutableArray<TagHelperDescriptor>.Empty, CodeAnalysis.CSharp.LanguageVersion.Default);
+        var projectWorkspaceState = ProjectWorkspaceState.Default;
 
         // Act
         await RunOnDispatcherThreadAsync(() =>
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/DefaultProjectSnapshotManagerTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/DefaultProjectSnapshotManagerTest.cs
index 79e7c2f88b..57635b7804 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/DefaultProjectSnapshotManagerTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/ProjectSystem/DefaultProjectSnapshotManagerTest.cs
@@ -61,7 +61,7 @@ public class DefaultProjectSnapshotManagerTest : ProjectSnapshotManagerDispatche
 
         _projectManager = new TestProjectSnapshotManager(Enumerable.Empty<IProjectSnapshotChangeTrigger>(), Workspace, Dispatcher);
 
-        _projectWorkspaceStateWithTagHelpers = new ProjectWorkspaceState(_tagHelperResolver.TagHelpers, default);
+        _projectWorkspaceStateWithTagHelpers = ProjectWorkspaceState.Create(_tagHelperResolver.TagHelpers);
 
         _sourceText = SourceText.From("Hello world");
     }
diff --git a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/VsSolutionUpdatesProjectSnapshotChangeTriggerTest.cs b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/VsSolutionUpdatesProjectSnapshotChangeTriggerTest.cs
index cb7b7d960a..45efd7ba2d 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/VsSolutionUpdatesProjectSnapshotChangeTriggerTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/VsSolutionUpdatesProjectSnapshotChangeTriggerTest.cs
@@ -8,6 +8,7 @@ using System.Collections.Immutable;
 using System.IO;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
+using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common;
 using Microsoft.AspNetCore.Razor.Test.Common.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
@@ -39,14 +40,24 @@ public class VsSolutionUpdatesProjectSnapshotChangeTriggerTest : ToolingTestBase
         _someProject = new HostProject(TestProjectData.SomeProject.FilePath, TestProjectData.SomeProject.IntermediateOutputPath, FallbackRazorConfiguration.MVC_1_0, TestProjectData.SomeProject.RootNamespace);
         _someOtherProject = new HostProject(TestProjectData.AnotherProject.FilePath, TestProjectData.AnotherProject.IntermediateOutputPath, FallbackRazorConfiguration.MVC_2_0, TestProjectData.AnotherProject.RootNamespace);
 
-        _workspace = TestWorkspace.Create(w => _someWorkspaceProject = w.AddProject(ProjectInfo.Create(
-                ProjectId.CreateNewId(),
-                VersionStamp.Create(),
-                "SomeProject",
-                "SomeProject",
-                LanguageNames.CSharp,
-                filePath: _someProject.FilePath).WithCompilationOutputInfo(new CompilationOutputInfo().WithAssemblyPath(Path.Combine(_someProject.IntermediateOutputPath, "SomeProject.dll")))));
+        var projectEngineFactory = Mock.Of<ProjectSnapshotProjectEngineFactory>(MockBehavior.Strict);
+        var testServices = TestServices.Create([projectEngineFactory], []);
 
+        _workspace = TestWorkspace.Create(testServices,
+            w =>
+            {
+                _someWorkspaceProject = w.AddProject(
+                    ProjectInfo.Create(
+                        ProjectId.CreateNewId(),
+                        VersionStamp.Create(),
+                        "SomeProject",
+                        "SomeProject",
+                        LanguageNames.CSharp,
+                        filePath: _someProject.FilePath)
+                    .WithCompilationOutputInfo(
+                        new CompilationOutputInfo()
+                            .WithAssemblyPath(Path.Combine(_someProject.IntermediateOutputPath, "SomeProject.dll"))));
+            });
         AddDisposable(_workspace);
     }
 
@@ -189,11 +200,17 @@ public class VsSolutionUpdatesProjectSnapshotChangeTriggerTest : ToolingTestBase
             .Returns(VSConstants.S_OK);
 
         var services = new Mock<IServiceProvider>(MockBehavior.Strict);
-        services.Setup(s => s.GetService(It.Is<Type>(f => f == typeof(SVsSolutionBuildManager)))).Returns(buildManager.Object);
+        services
+            .Setup(s => s.GetService(It.Is<Type>(f => f == typeof(SVsSolutionBuildManager))))
+            .Returns(buildManager.Object);
+
+        var projectEngineFactory = Mock.Of<ProjectSnapshotProjectEngineFactory>(MockBehavior.Strict);
+
         var projectSnapshot = new ProjectSnapshot(
             ProjectState.Create(
-                _workspace.Services,
-                new HostProject("/Some/Unknown/Path.csproj", "/Some/Unknown/obj", RazorConfiguration.Default, "Path")));
+                projectEngineFactory,
+                new HostProject("/Some/Unknown/Path.csproj", "/Some/Unknown/obj", RazorConfiguration.Default, "Path"),
+                ProjectWorkspaceState.Default));
         var expectedProjectPath = projectSnapshot.FilePath;
 
         var projectService = new Mock<TextBufferProjectService>(MockBehavior.Strict);
diff --git a/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Guest/ProjectSnapshotSynchronizationServiceTest.cs b/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Guest/ProjectSnapshotSynchronizationServiceTest.cs
index 3deb09ebdd..38664a46f2 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Guest/ProjectSnapshotSynchronizationServiceTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Guest/ProjectSnapshotSynchronizationServiceTest.cs
@@ -34,9 +34,8 @@ public class ProjectSnapshotSynchronizationServiceTest : WorkspaceTestBase
 
         _projectSnapshotManager = new TestProjectSnapshotManager(Workspace, new TestProjectSnapshotManagerDispatcher());
 
-        _projectWorkspaceStateWithTagHelpers = new ProjectWorkspaceState(ImmutableArray.Create(
-            TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()),
-            csharpLanguageVersion: default);
+        _projectWorkspaceStateWithTagHelpers = ProjectWorkspaceState.Create(ImmutableArray.Create(
+            TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build()));
     }
 
     [Fact]
diff --git a/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Host/DefaultProjectSnapshotManagerProxyTest.cs b/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Host/DefaultProjectSnapshotManagerProxyTest.cs
index e29d09aa3f..b9ad63dcb6 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Host/DefaultProjectSnapshotManagerProxyTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/Host/DefaultProjectSnapshotManagerProxyTest.cs
@@ -9,10 +9,11 @@ using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.ProjectSystem;
 using Microsoft.AspNetCore.Razor.Test.Common.Editor;
-using Microsoft.AspNetCore.Razor.Test.Common.Workspaces;
+using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 using Microsoft.VisualStudio.LiveShare.Razor.Test;
 using Microsoft.VisualStudio.Threading;
+using Moq;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -20,33 +21,29 @@ namespace Microsoft.VisualStudio.LiveShare.Razor.Host;
 
 public class DefaultProjectSnapshotManagerProxyTest : ProjectSnapshotManagerDispatcherTestBase
 {
-    private readonly CodeAnalysis.Workspace _workspace;
     private readonly IProjectSnapshot _projectSnapshot1;
     private readonly IProjectSnapshot _projectSnapshot2;
 
     public DefaultProjectSnapshotManagerProxyTest(ITestOutputHelper testOutput)
         : base(testOutput)
     {
-        _workspace = TestWorkspace.Create();
-        AddDisposable(_workspace);
+        var projectEngineFactory = Mock.Of<ProjectSnapshotProjectEngineFactory>(MockBehavior.Strict);
 
-        var projectWorkspaceState1 = new ProjectWorkspaceState(ImmutableArray.Create(
-            TagHelperDescriptorBuilder.Create("test1", "TestAssembly1").Build()),
-            csharpLanguageVersion: default);
+        var projectWorkspaceState1 = ProjectWorkspaceState.Create(ImmutableArray.Create(
+            TagHelperDescriptorBuilder.Create("test1", "TestAssembly1").Build()));
 
         _projectSnapshot1 = new ProjectSnapshot(
             ProjectState.Create(
-                _workspace.Services,
+                projectEngineFactory,
                 new HostProject("/host/path/to/project1.csproj", "/host/path/to/obj", RazorConfiguration.Default, "project1"),
                 projectWorkspaceState1));
 
-        var projectWorkspaceState2 = new ProjectWorkspaceState(ImmutableArray.Create(
-            TagHelperDescriptorBuilder.Create("test2", "TestAssembly2").Build()),
-            csharpLanguageVersion: default);
+        var projectWorkspaceState2 = ProjectWorkspaceState.Create(ImmutableArray.Create(
+            TagHelperDescriptorBuilder.Create("test2", "TestAssembly2").Build()));
 
         _projectSnapshot2 = new ProjectSnapshot(
             ProjectState.Create(
-                _workspace.Services,
+                projectEngineFactory,
                 new HostProject("/host/path/to/project2.csproj", "/host/path/to/obj", RazorConfiguration.Default, "project2"),
                 projectWorkspaceState2));
     }
@@ -196,13 +193,9 @@ public class DefaultProjectSnapshotManagerProxyTest : ProjectSnapshotManagerDisp
         Assert.Same(state1, state2);
     }
 
-    private class TestProjectSnapshotManager : ProjectSnapshotManager
+    private class TestProjectSnapshotManager(params IProjectSnapshot[] projects) : ProjectSnapshotManager
     {
-        private ImmutableArray<IProjectSnapshot> _projects;
-        public TestProjectSnapshotManager(params IProjectSnapshot[] projects)
-        {
-            _projects = projects.ToImmutableArray();
-        }
+        private ImmutableArray<IProjectSnapshot> _projects = projects.ToImmutableArray();
 
         public override ImmutableArray<IProjectSnapshot> GetProjects() => _projects;
 
diff --git a/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/SerializationTest.cs b/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/SerializationTest.cs
index a01f92e9b9..e6ce7907cc 100644
--- a/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/SerializationTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.LiveShare.Razor.Test/SerializationTest.cs
@@ -13,13 +13,8 @@ using Xunit.Abstractions;
 
 namespace Microsoft.VisualStudio.LiveShare.Razor;
 
-public class SerializationTest : ToolingTestBase
+public class SerializationTest(ITestOutputHelper testOutput) : ToolingTestBase(testOutput)
 {
-    public SerializationTest(ITestOutputHelper testOutput)
-        : base(testOutput)
-    {
-    }
-
     [Fact]
     public void ProjectSnapshotHandleProxy_RoundTripsProperly()
     {
@@ -28,7 +23,7 @@ public class SerializationTest : ToolingTestBase
             TagHelperDescriptorBuilder.Create("TestTagHelper", "TestAssembly").Build(),
             TagHelperDescriptorBuilder.Create("TestTagHelper2", "TestAssembly2").Build());
 
-        var projectWorkspaceState = new ProjectWorkspaceState(tagHelpers, default);
+        var projectWorkspaceState = ProjectWorkspaceState.Create(tagHelpers);
         var expectedConfiguration = RazorConfiguration.Default;
         var expectedRootNamespace = "project";
         var handle = new ProjectSnapshotHandleProxy(new Uri("vsls://some/path/project.csproj"), new Uri("vsls://some/path/obj"), RazorConfiguration.Default, expectedRootNamespace, projectWorkspaceState);