[eng/common] Update-DocsMsMetadata.ps1 can fail the build on invalid packages

eng/common/pipelines/templates/steps/docsms-ensure-validation.yml

@@ -0,0 +1,11 @@
+steps:
+# Fail the build if any of the packages failed validation. Valid values are
+# "true" or "false"
+- pwsh: |
+    if ('$(DocsMsPackagesAllValid)' -eq 'true') {
+      Write-Host "All packages passed validation."
+    } else {
+      Write-Error "Some packages failed validation."
+      exit 1
+    }
+  displayName: Check package validation results

eng/common/scripts/Update-DocsMsMetadata.ps1

@@ -230,17 +230,40 @@ function UpdateDocsMsMetadataForPackage($packageInfoJsonLocation) {
   Set-Content -Path $readmeLocation -Value $outputReadmeContent
 }
 
-# For daily update and release, validate DocsMS publishing using the language-specific validation function
-if ($ValidateDocsMsPackagesFn -and (Test-Path "Function:$ValidateDocsMsPackagesFn")) {
-  Write-Host "Validating the packages..."
-
-  $packageInfos = @($PackageInfoJsonLocations | ForEach-Object { GetPackageInfoJson $_ })
+$allSucceeded = $true
+foreach ($packageInfoLocation in $PackageInfoJsonLocations) {
 
-  &$ValidateDocsMsPackagesFn -PackageInfos $packageInfos -PackageSourceOverride $PackageSourceOverride -DocValidationImageId $DocValidationImageId -DocRepoLocation $DocRepoLocation
-}
+  if ($ValidateDocsMsPackagesFn -and (Test-Path "Function:$ValidateDocsMsPackagesFn")) {
+    Write-Host "Validating the packages..."
+
+    $packageInfo =  GetPackageInfoJson $packageInfoLocation
+    # This calls a function named "Validate-${Language}-DocMsPackages" 
+    # declared in common.ps1, implemented in Language-Settings.ps1
+    $isValid = &$ValidateDocsMsPackagesFn `
+      -PackageInfos $packageInfo `
+      -PackageSourceOverride $PackageSourceOverride `
+      -DocValidationImageId $DocValidationImageId `
+      -DocRepoLocation $DocRepoLocation
+
+    if (!$isValid) {
+      Write-Host "Package validation failed for package: $packageInfoLocation"
+      $allSucceeded = $false
+
+      # Skip the later call to UpdateDocsMsMetadataForPackage because this 
+      # package has not passed validation
+      continue
+    }
+  }
 
-foreach ($packageInfoLocation in $PackageInfoJsonLocations) {
   Write-Host "Updating metadata for package: $packageInfoLocation"
   # Convert package metadata json file to metadata json property.
   UpdateDocsMsMetadataForPackage $packageInfoLocation
 }
+
+# Set a variable which will be used by the pipeline later to fail the build if
+# any packages failed validation
+if ($allSucceeded) {
+  Write-Host "##vso[task.setvariable variable=DocsMsPackagesAllValid;]$true"
+} else { 
+  Write-Host "##vso[task.setvariable variable=DocsMsPackagesAllValid;]$false"
+}