Add init.ps1 and Install-DotNetSdk.ps1 scripts

Closes #12

.gitattributes

@@ -3,6 +3,9 @@
 ###############################################################################
 * text=auto
 
+# Ensure bash shell scripts use LF line endings
+*.sh eol=lf
+
 ###############################################################################
 # Set default behavior for command prompt diff.
 #

CONTRIBUTING.md

@@ -17,8 +17,13 @@ For example if 2.2.300 is specified, you may install 2.2.300, 2.2.301, or 2.2.31
 while the 2.2.400 version would not be considered compatible by .NET SDK.
 See [.NET Core Versioning](https://docs.microsoft.com/en-us/dotnet/core/versions/) for more information.
 
+All dependencies can be installed by running the `init.ps1` script at the root of the repository
+using Windows PowerShell or [PowerShell Core][pwsh] (on any OS).
+
 This repository can be built on Windows, Linux, and OSX.
 
 ## Building
 
 Building, testing, and packing this repository can be done by using the standard dotnet CLI commands (e.g. `dotnet build`, `dotnet test`, `dotnet pack`, etc.).
+
+[pwsh]: https://docs.microsoft.com/en-us/powershell/scripting/install/installing-powershell?view=powershell-6

init.ps1

@@ -0,0 +1,9 @@
+<#
+.SYNOPSIS
+Installs dependencies required to build and test the projects in this repository.
+#>
+[CmdletBinding(SupportsShouldProcess=$true)]
+Param (
+)
+
+& "$PSScriptRoot\tools\Install-DotNetSdk.ps1"

tools/Install-DotNetSdk.ps1

@@ -0,0 +1,54 @@
+<#
+.SYNOPSIS
+Installs the .NET SDK specified in the global.json file at the root of this repository,
+along with supporting .NET Core runtimes used for testing.
+#>
+[CmdletBinding(SupportsShouldProcess=$true,ConfirmImpact='Medium')]
+Param (
+)
+
+$DotNetInstallScriptRoot = Resolve-Path $PSScriptRoot\..\obj
+$sdkVersion = & "$PSScriptRoot\..\azure-pipelines\variables\DotNetSdkVersion.ps1"
+
+if ($IsMacOS -or $IsLinux) {
+    $DownloadUri = "https://dot.net/v1/dotnet-install.sh"
+    $DotNetInstallScriptPath = "$DotNetInstallScriptRoot/dotnet-install.sh"
+} else {
+    $DownloadUri = "https://dot.net/v1/dotnet-install.ps1"
+    $DotNetInstallScriptPath = "$DotNetInstallScriptRoot\dotnet-install.ps1"
+}
+
+if (-not (Test-Path $DotNetInstallScriptPath)) {
+    Invoke-WebRequest -Uri $DownloadUri -OutFile $DotNetInstallScriptPath
+    chmod +x $DotNetInstallScriptPath
+}
+
+if ($PSCmdlet.ShouldProcess(".NET Core SDK $sdkVersion", "Install")) {
+    & $DotNetInstallScriptPath -Version $sdkVersion -Architecture x64
+} else {
+    & $DotNetInstallScriptPath -Version $sdkVersion -Architecture x64 -DryRun
+}
+
+# Search for all .NET Core runtime versions referenced from MSBuild projects and arrange to install them.
+$runtimeVersions = @()
+Get-ChildItem "$PSScriptRoot\..\src\*.*proj" -Recurse |% {
+    $projXml = [xml](Get-Content -Path $_)
+    $targetFrameworks = $projXml.Project.PropertyGroup.TargetFramework
+    if (!$targetFrameworks) {
+        $targetFrameworks = $projXml.Project.PropertyGroup.TargetFrameworks
+        if ($targetFrameworks) {
+            $targetFrameworks = $targetFrameworks.Split(';')
+        }
+    }
+    $targetFrameworks |? { $_ -match 'netcoreapp(\d+\.\d+)' } |% {
+        $runtimeVersions += $Matches[1]
+    }
+}
+
+$runtimeVersions | Get-Unique |% {
+    if ($PSCmdlet.ShouldProcess(".NET Core runtime $_", "Install")) {
+        & $DotNetInstallScriptPath -Channel $_ -Runtime dotnet -Architecture x64
+    } else {
+        & $DotNetInstallScriptPath -Channel $_ -Runtime dotnet -Architecture x64 -DryRun
+    }
+}