chore: Exclude @types namespace from ClearlyDefined check (#7046)

#### Details

We frequently get dependabot PR's for the `@types` namespace, which are
always devDependencies. To streamline maintenance, this PR automatically
excludes these packages from the ClearlyDefined check. It also updates
the validation script and removes the packages in the `@types` namespace
that we've collected so far.

It also includes 2 analyzer-suggested changes of moving `$null` from the
RHS to the LHS of the comparison to prevent accidentally setting the
value instead of comparing it.

##### Motivation

Streamline dependabot handling

##### Context

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a later PR to handle? -->

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#### Pull request checklist
<!-- If a checklist item is not applicable to this change, write "n/a"
in the checkbox -->
- [n/a] Addresses an existing issue: #0000
- [x] Ran `yarn fastpass`
- [n/a] Added/updated relevant unit test(s) (and ran `yarn test`)
- [n/a] Verified code coverage for the changes made. Check coverage
report at: `<rootDir>/test-results/unit/coverage`
- [x] PR title *AND* final merge commit title both start with a semantic
tag (`fix:`, `chore:`, `feat(feature-name):`, `refactor:`). See
`CONTRIBUTING.md`.
- [n/a] (UI changes only) Added screenshots/GIFs to description above
- [n/a] (UI changes only) Verified usability with NVDA/JAWS

tools/clearly-defined/ValidateScript.bat

@@ -71,6 +71,15 @@ if errorlevel 1 goto fail
 echo OK
 echo.
 
+@echo Passing case: local PR build of dependabot branch with @types namespace
+set BUILD_SOURCEBRANCH=
+set GITHUB_HEAD_REF=
+echo pwsh -f ./check-clearly-defined.ps1 -PipelineType local -BranchName dependabot/npm_and_yarn/types/jest-1.10000.1
+pwsh -f ./check-clearly-defined.ps1 -PipelineType local -BranchName dependabot/npm_and_yarn/types/jest-1.10000.1
+if errorlevel 1 goto fail
+echo OK
+echo.
+
 @echo Failing case: Package that does not exist in ClearlyDefined
 echo pwsh -f ./check-clearly-defined.ps1 -PipelineType local -BranchName dependabot/nuget/src/Axe.Windows-2.99.99
 pwsh -f ./check-clearly-defined.ps1 -PipelineType local -BranchName dependabot/nuget/src/Axe.Windows-2.99.99

tools/clearly-defined/check-clearly-defined.ps1

@@ -66,7 +66,7 @@ function GetBranchName([string]$pipelineType, [string]$branchName) {
             }
             "ado" {
                 $prBranchName = $Env:SYSTEM_PULLREQUEST_SOURCEBRANCH
-                if ($prBranchName -eq $null) {
+                if ($null -eq $prBranchName) {
                     $trimmedBranchName = ($Env:BUILD_SOURCEBRANCH).Trim().Replace("refs/heads/","")
                 } else {
                     $trimmedBranchName = $prBranchName.Trim()
@@ -105,7 +105,7 @@ function IsPackageExcluded([string]$namespaceAndPackage) {
     # licensing purposes, can be added to clearly-defined-exclusions.json
     $exclusionFile = Join-Path $PSScriptRoot "clearly-defined-exclusions.json"
     $exclusions = Get-Content -Path $exclusionFile | ConvertFrom-Json
-    return $exclusions -ne $null -and $exclusions.Contains($namespaceAndPackage)
+    return $null -ne $exclusions -and $exclusions.Contains($namespaceAndPackage)
 }
 
 function IsGithubActionsType([string]$namespace){
@@ -128,6 +128,10 @@ function AdjustNamespace([string]$provider, [string]$rawNamespace) {
     return $rawNamespace
 }
 
+function IsTypesNamespace([string]$nameSpace){
+    return $nameSpace -eq "@types"
+}
+
 function GetUri([string]$branchName){
     $elements = $branchName.Split('/')
 
@@ -150,7 +154,13 @@ function GetUri([string]$branchName){
         $rawNamespace = $elements[2]
         $fullPackage = $elements[3]
     }
+
     $nameSpace = AdjustNamespace $provider $rawNamespace
+    if (IsTypesNamespace $nameSpace) {
+        Write-Host "Namespace is @types, skipping check"
+        Exit 0
+    }
+    
     $indexOfLastDash = $fullPackage.LastIndexOf('-') + 1
     $packageName = $fullPackage.Substring(0, $indexOfLastDash - 1)
     $packageVersion = $fullPackage.Substring($indexOfLastDash)

tools/clearly-defined/clearly-defined-exclusions.json

@@ -1,16 +1,5 @@
 [
     "@swc/core",
-    "@types/chrome",
-    "@types/enzyme",
-    "@types/enzyme-adapter-react-16",
-    "@types/jest",
-    "@types/jsdom",
-    "@types/luxon",
-    "@types/react-helmet",
-    "@types/serve-static",
-    "@types/ua-parser-js",
-    "@types/uuid",
-    "@types/webextension-polyfill",
     "@typescript-eslint/parser",
     "-/core-js-bundle",
     "-/esbuild",