chore(ci): fix update screenshot action to account for existing screenshot (#25190)

.github/workflows/actions/test-core-screenshot/action.yml

@@ -41,10 +41,41 @@ runs:
       shell: bash
       working-directory: ./core
     - name: Test and Update
+      id: test-and-update
       if: inputs.update == 'true'
-      run: npx playwright test --shard=${{ inputs.shard }}/${{ inputs.totalShards }} --update-snapshots
+      # Keep track of the files that were
+      # changed so they can be correctly restored
+      # in the combine step.
+      # To do this, we move only the changed files
+      # to a separate directory, while preserving the
+      # directory structure of the source.
+      # When, we create and archive of these results
+      # so that the combine step can simply
+      # unzip and move the changed files into place.
+      # We have extra logic added so that job runners
+      # that do not have any new screenshots do not create
+      # an unnecessary .zip.
+      # Note that we need to unzip directory to be "core"
+      # which is why we not using the upload-archive
+      # composite step here.
+      run: |
+        npx playwright test --shard=${{ inputs.shard }}/${{ inputs.totalShards }} --update-snapshots
+        git add src/\*.png --force
+        mkdir updated-screenshots
+        cd ../ && rsync -R --progress $(git diff --name-only --cached) core/updated-screenshots
+        if [ -d core/updated-screenshots/core ]; then
+          echo "::set-output name=hasUpdatedScreenshots::$(echo 'true')"
+          cd core/updated-screenshots
+          zip -q -r ../../UpdatedScreenshots-${{ inputs.shard }}-${{ inputs.totalShards }}.zip core
+        fi
       shell: bash
       working-directory: ./core
+    - name: Archive Updated Screenshots
+      if: inputs.update == 'true' && steps.test-and-update.outputs.hasUpdatedScreenshots == 'true'
+      uses: actions/upload-artifact@v2
+      with:
+        name: updated-screenshots-${{ inputs.shard }}-${{ inputs.totalShards }}
+        path: UpdatedScreenshots-${{ inputs.shard }}-${{ inputs.totalShards }}.zip
     - name: Archive Test Results
       # The always() ensures that this step
       # runs even if the previous step fails.
@@ -57,4 +88,4 @@ runs:
       with:
         name: test-results-${{ inputs.shard }}-${{ inputs.totalShards }}
         output: core/TestResults-${{ inputs.shard }}-${{ inputs.totalShards }}.zip
-        paths: core/playwright-report core/src
+        paths: core/playwright-report

.github/workflows/actions/update-reference-screenshots/action.yml

@@ -18,7 +18,7 @@ runs:
       # directory, including nested directories.
       # It then unzips every .zip to the root directory
       run: |
-        find . -type f -name '*.zip' -exec unzip -q -o -d ../ -- '{}'  -x '*.zip' \;
+        find . -type f -name 'UpdatedScreenshots-*.zip' -exec unzip -q -o -d ../ {} \;
       shell: bash
       working-directory: ./artifacts
     - name: Push Screenshots