Add support for skipping notifications via labels

README.md

@@ -45,4 +45,8 @@ request-number:
   descripton: "The pull request number"
   default: ${{ github.event.pull_request.number }}
   required: true
+no-sync-label:
+  description: "The label value, used for tagging PRs that shouldn't be checked"
+  default: 'no-branch-sync'
+  required: false
 ```

action.yml

@@ -1,5 +1,5 @@
 name: "Branch out-of-sync notifier"
-description: "Comments on an open PR if the base branch is out of sync with the target one."
+description: "Comments on a given PR if the base branch is out of sync with the target one."
 branding:
   icon: git-branch
   color: orange
@@ -21,6 +21,10 @@ inputs:
     descripton: "The pull request number"
     default: ${{ github.event.pull_request.number }}
     required: true
+  no-sync-label:
+    description: "The label value, used for tagging PRs that shouldn't be checked"
+    default: 'no-branch-sync'
+    required: false
 
 runs:
   using: "composite"
@@ -32,8 +36,24 @@ runs:
         submodules: true
         clean: false
 
+    - name: Check if no-sync label has been applied
+      uses: actions/github-script@v7
+      id: "check-for-no-sync-label"
+      with:
+        script: |
+          const labels = await github.paginate(github.rest.issues.listLabelsOnIssue, {
+              issue_number: ${{ inputs.request-number }},
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+          });
+
+          const projectedLabels = labels?.map(l => l.name);
+          const isNoSyncLabelApplied = projectedLabels.includes('${{ inputs.no-sync-label }}');
+          return isNoSyncLabelApplied;
+
     - name: Compare branches
       id: "compare-branches"
+      if: steps.check-for-no-sync-label.outputs.result == 'false'
       shell: bash
       run: |
         git fetch --all
@@ -42,6 +62,7 @@ runs:
 
     - name: Remove existing comments
       uses: actions/github-script@v7
+      if: steps.check-for-no-sync-label.outputs.result == 'false'
       env:
         # Top level env. variables are not supported in composite actions :(
         SYNC_BOT_TITLE: "Branch Sync Notifier"
@@ -77,7 +98,7 @@ runs:
 
           ### Hey, @${{ inputs.request-owner }}! :wave:
           ### Your branch is out of sync with the PR's target branch. 
-          ### Please rebase it on top of the latest changes from \`${{ github.event.pull_request.base.ref }}\` or merge them. :sun_with_face:
+          ### Please rebase it on top of the latest changes from \`${{ inputs.base-ref }}\` or merge them. :sun_with_face:
 
           **Run: [${{ github.run_number }}](${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}) :rabbit2:** 
           **Attempt: № \`${{ github.run_attempt }}\` :eyes:**