ci: make bump preview comment sticky (#2008)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: bearomorphism

.github/workflows/pr-bump-preview.yml

@@ -84,11 +84,27 @@ jobs:
             esac
           } > comment.md
 
+      # Look up an existing preview comment so the next step edits it in
+      # place instead of appending a new one on every run.
+      # `peter-evans/create-or-update-comment` does not search by body
+      # itself -- it only creates new comments, or updates a specific
+      # `comment-id`.
+      - name: Find existing preview comment
+        id: find-comment
+        uses: peter-evans/find-comment@v3
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: "github-actions[bot]"
+          body-includes: "<!-- commitizen-bump-preview -->"
+
       - name: Post or update PR comment
         uses: peter-evans/create-or-update-comment@v5
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
+          # When empty (no prior comment found) a new one is created;
+          # otherwise the existing comment is edited in place.
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
           issue-number: ${{ github.event.pull_request.number }}
           body-path: comment.md
-          body-includes: "<!-- commitizen-bump-preview -->"
           edit-mode: replace

docs/tutorials/github_actions.md

@@ -205,12 +205,20 @@ jobs:
                 ;;
             esac
           } > comment.md
-      - uses: peter-evans/create-or-update-comment@v4
+      - name: Find existing preview comment
+        id: find-comment
+        uses: peter-evans/find-comment@v3
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           issue-number: ${{ github.event.pull_request.number }}
-          body-path: comment.md
+          comment-author: "github-actions[bot]"
           body-includes: "<!-- commitizen-bump-preview -->"
+      - uses: peter-evans/create-or-update-comment@v5
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
+          issue-number: ${{ github.event.pull_request.number }}
+          body-path: comment.md
           edit-mode: replace
 ```
 
@@ -235,10 +243,13 @@ jobs:
   `update_changelog_on_bump` is set in your config, also the changelog
   entries that would be produced). Exit code `21` (`NoneIncrementExit`)
   is treated as "no eligible bump" rather than a failure.
-- **Sticky comment**: The hidden HTML marker `<!-- commitizen-bump-preview -->`
-  lets [`peter-evans/create-or-update-comment`](https://github.com/peter-evans/create-or-update-comment)
-  find and replace the previous preview on every push, instead of leaving a
-  growing trail of comments.
+- **Sticky comment**: [`peter-evans/find-comment`](https://github.com/peter-evans/find-comment)
+  looks up an existing comment by the hidden HTML marker
+  `<!-- commitizen-bump-preview -->` and bot author, then
+  [`peter-evans/create-or-update-comment`](https://github.com/peter-evans/create-or-update-comment)
+  edits it in place (or creates a new one on the first run when the
+  marker is not yet present), instead of leaving a growing trail of
+  comments.
 
 [jinja]: https://github.com/commitizen-tools/commitizen/blob/master/commitizen/changelog.py