ci: add pr title linting to ci workflow

Author: ayushiahjolia

.github/workflows/ci.yml

@@ -12,6 +12,18 @@ on:
     branches: [ main ]
 
 jobs:
+  lint-pr-title:
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+    - name: Set up Python
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+      with:
+        python-version: "3.12"
+    - name: Lint PR title
+      run: python ops/lintcommit.py --subject "${{ github.event.pull_request.title }}"
+
   build:
     runs-on: ubuntu-latest
     strategy:

ops/lintcommit.py

@@ -192,7 +192,28 @@ def run_local() -> None:
 
 
 def main() -> None:
-    run_local()
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description="Lint commit messages for conventional commits compliance."
+    )
+    parser.add_argument(
+        "--subject",
+        default=None,
+        help="Validate a single subject line (e.g. a PR title). "
+        "When omitted, runs in local mode checking commits ahead of origin/main.",
+    )
+    args = parser.parse_args()
+
+    if args.subject is not None:
+        error: str | None = validate_subject(args.subject)
+        if error:
+            print(f"FAIL: {args.subject}", file=sys.stderr)
+            print(f"  Error: {error}", file=sys.stderr)
+            sys.exit(1)
+        print(f"PASS: {args.subject}")
+    else:
+        run_local()
 
 
 if __name__ == "__main__":