Enhance PR checks by adding SHA generation for lib/ folder and pubspec.yaml, and implement hash comparison to skip steps if unchanged

Author: FMorschel

.github/workflows/pr-to-stable.yaml

@@ -26,16 +26,63 @@ jobs:
           git clone --branch ${{ github.head_ref }} --single-branch --depth 1 https://github.com/${{ github.repository }} new_version
           rm -rf new_version/.git
 
+      - name: Generate SHA of lib/ folder
+        run: |
+          (cd new_version/lib && find . -type f -exec sha1sum {} \; | sort | sha1sum | awk '{print $1}') > ../lib_folder.sha
+          cat ../lib_folder.sha
+
+      - name: Generate SHA of pubspec.yaml
+        run: |
+          sha1sum new_version/pubspec.yaml | awk '{print $1}' > pubspec_yaml.sha
+          cat pubspec_yaml.sha
+
+      - name: Fetch and verify last apitool-meta comment from PR
+        id: check_hashes
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          COMMENTS=$(gh pr view ${{ github.event.pull_request.number }} --json comments --jq '.comments')
+          echo "$COMMENTS" | jq -r '.[] | select(.author.login=="github-actions[bot]") | select(.body | contains("<!-- apitool-meta")) | .body' | tail -n 1 > last_apitool_meta_comment.txt
+          cat last_apitool_meta_comment.txt
+
+          # Extract hashes from the last comment
+          LAST_LIB_SHA=$(grep 'lib_sha:' last_apitool_meta_comment.txt | awk -F': ' '{print $2}')
+          LAST_PUBSPEC_SHA=$(grep 'pubspec_yaml_sha:' last_apitool_meta_comment.txt | awk -F': ' '{print $2}')
+
+          # Read current hashes
+          CUR_LIB_SHA=$(cat lib_folder.sha)
+          CUR_PUBSPEC_SHA=$(cat pubspec_yaml.sha)
+
+          # Compare and print result, set output
+          if [ "$LAST_LIB_SHA" = "$CUR_LIB_SHA" ] && [ "$LAST_PUBSPEC_SHA" = "$CUR_PUBSPEC_SHA" ]; then
+            echo "Hashes match: lib/ and pubspec.yaml have not changed since last comment."
+            echo "skip_steps=true" >> $GITHUB_OUTPUT
+          else
+            echo "Hashes do not match: lib/ or pubspec.yaml have changed since last comment."
+            echo "skip_steps=false" >> $GITHUB_OUTPUT
+          fi
+
       - name: Set up Dart
+        if: steps.check_hashes.outputs.skip_steps != 'true'
         uses: dart-lang/setup-dart@v1
 
       - name: Run API diff and save report
+        if: steps.check_hashes.outputs.skip_steps != 'true'
         continue-on-error: true
         run: |
           dart pub global activate dart_apitool && dart-apitool diff --old ./old_version --new ./new_version --ignore-prerelease on --report-format markdown --report-file-path apitool_report.md
 
       - name: Comment API diff report on PR
+        if: steps.check_hashes.outputs.skip_steps != 'true'
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          gh pr comment ${{ github.event.pull_request.number }} --body "$(cat apitool_report.md)"
+          LIB_SHA=$(cat lib_folder.sha)
+          PUBSPEC_SHA=$(cat pubspec_yaml.sha)
+          echo "$(cat apitool_report.md)
+
+          <!-- apitool-meta
+          lib_sha: $LIB_SHA
+          pubspec_yaml_sha: $PUBSPEC_SHA
+          -->" > apitool_report_with_meta.md
+          gh pr comment ${{ github.event.pull_request.number }} --body "$(cat apitool_report_with_meta.md)"