[TypeSpecValidation] Apply "all" suppressions when core files changed (…

…Azure#30805)

- Fixes Azure#30521

eng/scripts/Get-TypeSpec-Folders.ps1

@@ -9,10 +9,13 @@ Set-StrictMode -Version 3
 . $PSScriptRoot/ChangedFiles-Functions.ps1
 
 $repoPath = Resolve-Path "$PSScriptRoot/../.."
+
 $checkAllPath = ((Get-ChildItem "specification" -Directory).Name -replace '^', 'specification/') -replace '$', '/'
+$checkedAll = $false
 
 if ($CheckAll) {
   $changedFiles = $checkAllPath
+  $checkedAll = $true
 }
 else {
   $changedFiles = @(Get-ChangedFiles -baseCommitish $BaseCommitish -targetCommitish $TargetCommitish -diffFilter "")
@@ -21,6 +24,7 @@ else {
   if ($coreChangedFiles) {
     Write-Verbose "Found changes to core eng or root files so checking all specs."
     $changedFiles = $checkAllPath
+    $checkedAll = $true
   }
   else {
     $changedFiles = Get-ChangedFilesUnderSpecification $changedFiles
@@ -49,4 +53,4 @@ foreach ($skippedTypespecFolder in $skippedTypespecFolders | Select-Object -Uniq
 
 $typespecFolders = $typespecFolders | ForEach-Object { [IO.Path]::GetRelativePath($repoPath, $_) -replace '\\', '/' } | Sort-Object -Unique
 
-return $typespecFolders
+return @($typespecFolders, $checkedAll)

eng/scripts/TypeSpec-Validation.ps1

@@ -10,15 +10,15 @@ param (
 . $PSScriptRoot/Logging-Functions.ps1
 . $PSScriptRoot/Suppressions-Functions.ps1
 
-$typespecFolders = &"$PSScriptRoot/Get-TypeSpec-Folders.ps1" -BaseCommitish:$BaseCommitish -TargetCommitish:$TargetCommitish -CheckAll:$CheckAll
+$typespecFolders, $checkedAll = &"$PSScriptRoot/Get-TypeSpec-Folders.ps1" -BaseCommitish:$BaseCommitish -TargetCommitish:$TargetCommitish -CheckAll:$CheckAll
 
 $typespecFoldersWithFailures = @()
 if ($typespecFolders) {
   $typespecFolders = $typespecFolders.Split('',[System.StringSplitOptions]::RemoveEmptyEntries)
   foreach ($typespecFolder in $typespecFolders) {
     LogGroupStart "Validating $typespecFolder"
 
-    if ($CheckAll) {
+    if ($checkedAll) {
       $suppression = Get-Suppression "TypeSpecValidationAll" $typespecFolder
       if ($suppression) {
         $reason = $suppression["reason"] ?? "<no reason specified>"