chore: improve auto PR comments when windows cached things change

.github/workflows/check-windows-packages-change.yml

@@ -0,0 +1,71 @@
+name: Make windows components change PR review comment
+on: pull_request
+
+jobs:
+  compare-components-output:
+    name: Compare components.json and windows_settings.json for each windows VHD
+    runs-on: windows-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v4
+        with:
+          ref: master
+          path: master
+          fetch-depth: 1
+
+      - name: Check out repository code
+        uses: actions/checkout@v4
+        with:
+          path: pr
+          fetch-depth: 1
+
+      - name: Produce vhd files - master
+        id: makeDiff
+        shell: pwsh
+        run: |
+          cd pr
+          mkdir vhd_files
+
+          pwsh -c vhdbuilder/scripts/windows/generate_cached_stuff_list.ps1 vhd_files vhdbuilder/packer/windows/components_json_helpers.ps1 ../master/vhdbuilder/packer/windows/windows_settings.json ../master/parts/common/components.json 
+
+          git add vhd_files
+          git config user.email "[email protected]"
+          git config user.name "Your Name"
+          git commit -m "versions of files from master"
+
+          pwsh -c vhdbuilder/scripts/windows/generate_cached_stuff_list.ps1 vhd_files vhdbuilder/packer/windows/components_json_helpers.ps1 vhdbuilder/packer/windows/windows_settings.json parts/common/components.json 
+
+          $diffFile = "../diff.md"
+          git diff --quiet
+          if ( $LASTEXITCODE -eq "0" ) {
+            Write-Output "No changes to cached containers or packages on Windows VHDs" > $diffFile
+          } else {
+            Write-Output "Changes cached containers or packages on windows VHDs" > $diffFile
+            Write-Output "" >> $diffFile
+            Write-Output '```diff' >> $diffFile
+            git diff --unified=0 >> $diffFile
+            Write-Output '```' >> $diffFile
+
+            dir $diffFile
+            Get-Content $diffFile
+          }
+
+      - name: remove comment from PR
+        # Removing and then adding the comment means that the comment will always appear at the bottom of the PR.
+        uses: thollander/actions-comment-pull-request@v3
+        with:
+          mode: delete
+          comment-tag: "WINDOWS_VHD_CONTENT_DIFF"
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
+
+      - name: Add comment to PR
+        uses: thollander/actions-comment-pull-request@v3
+        if: ${{ hashFiles('diff.md') != '' }}
+        with:
+          file-path: "diff.md"
+          comment-tag: "WINDOWS_VHD_CONTENT_DIFF"
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}

.github/workflows/validate-windows-ut.yml

@@ -23,62 +23,3 @@ jobs:
         run: |
           Install-Module -Name powershell-yaml -Force
           Invoke-Pester staging/cse/windows/*.tests.ps1 -Passthru
-
-  compare-components-output:
-    name: Compare components.json for each windows VHD
-    runs-on: windows-latest
-    permissions:
-      pull-requests: write
-    steps:
-      - name: Check out repository code
-        uses: actions/checkout@v4
-        with:
-          ref: master
-          path: master
-          fetch-depth: 1
-
-      - name: Check out repository code
-        uses: actions/checkout@v4
-        with:
-          path: pr
-          fetch-depth: 1
-
-      - name: Produce vhd files - master
-        shell: pwsh
-        run: |
-          cd pr
-          mkdir vhd_files
-
-          pwsh -c vhdbuilder/scripts/windows/generate_cached_stuff_list.ps1 vhd_files vhdbuilder/packer/windows/components_json_helpers.ps1 ../master/vhdbuilder/packer/windows/windows_settings.json ../master/parts/common/components.json 
-
-          git add vhd_files
-          git config user.email "[email protected]"
-          git config user.name "Your Name"
-          git commit -m "versions of files from master"
-
-          pwsh -c vhdbuilder/scripts/windows/generate_cached_stuff_list.ps1 vhd_files vhdbuilder/packer/windows/components_json_helpers.ps1 vhdbuilder/packer/windows/windows_settings.json parts/common/components.json 
-
-          mkdir -p ../.github/workflows
-          $diffFile = "../.github/workflows/diff.md"
-
-          git diff --quiet
-          if ( $LASTEXITCODE -eq "0" ) {
-            Write-Output "No changes to cached containers or packages on Windows VHDs" > $diffFile
-          } else {
-            Write-Output "Changes cached containers or packages on windows VHDs" > $diffFile
-            Write-Output "" >> $diffFile
-            Write-Output '```diff' >> $diffFile
-            git diff >> $diffFile
-            Write-Output '```' >> $diffFile
-          }
-
-          dir $diffFile
-          Get-Content $diffFile
-
-      - name: Add comment to PR
-        uses: NejcZdovc/comment-pr@v2
-        with:
-            file: "diff.md"
-            identifier: "WINDOWS_VHD_CONTENT_DIFF"
-        env:
-          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}