ci: automatically lint PR titles for conventional commits

.github/workflows/conventional_commits.yml

@@ -0,0 +1,54 @@
+name: "Lint PR"
+
+on:
+    pull_request_target:
+        types:
+            - opened
+            - edited
+            - synchronize
+
+permissions:
+    pull-requests: write
+
+jobs:
+    main:
+        name: Validate PR title
+        runs-on: ubuntu-latest
+        steps:
+            - uses: amannn/action-semantic-pull-request@v5
+              id: lint_pr_title
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+              with:
+                  requireScope: false
+                  validateSingleCommit: true
+                  validateSingleCommitMatchesPrTitle: true
+                  subjectPattern: ^(?![A-Z]).+$
+                  subjectPatternError: |
+                      The subject "{subject}" found in the pull request title "{title}"
+                      didn't match the convention. Please ensure it
+                      doesn't start with an uppercase character.
+
+            - uses: marocchino/sticky-pull-request-comment@v2
+              # When the previous steps fails, the workflow would stop. By adding this
+              # condition you can continue the execution with the populated error message.
+              if: always() && (steps.lint_pr_title.outputs.error_message != null)
+              with:
+                  header: pr-title-lint-error
+                  message: |
+                      Hey there and thank you for opening this pull request!
+
+                      Commits and pull requests for this mod follow the [Conventional Commits specification](https://www.conventionalcommits.org/en/v1.0.0/), and it looks like your proposed title needs to be adjusted.
+
+                      Details:
+
+                      ```
+                      ${{ steps.lint_pr_title.outputs.error_message }}
+                      ```
+
+            # Delete a previous comment when the issue has been resolved
+            - if: ${{ steps.lint_pr_title.outputs.error_message == null }}
+              uses: marocchino/sticky-pull-request-comment@v2
+              with:
+                  header: pr-title-lint-error
+                  delete: true