refactor(ci): replace JS PR title linter with Python commit linter

Author: ayushiahjolia

.github/workflows/ci.yml

@@ -12,22 +12,7 @@ on:
     branches: [ main ]
 
 jobs:
-  lint-commits:
-    # Note: To re-run `lint-commits` after fixing the PR title, close-and-reopen the PR.
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
-      - name: Use Node.js
-        uses: actions/setup-node@6044e13b5dc448c55e2357c09f80417699197238 # v6.2.0
-        with:
-          node-version: 22.x
-      - name: Check PR title
-        run: |
-          node "$GITHUB_WORKSPACE/.github/workflows/lintcommit.js"
-
   build:
-    needs: lint-commits
-
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false

.github/workflows/lintcommit.js

@@ -30,6 +30,14 @@ There is a convenience script for the above that you can run from the root of th
 ops/ci-checks.sh
 ```
 
+This script also validates your commit messages against the [Conventional Commits](https://www.conventionalcommits.org/) format.
+If you have uncommitted changes, it will skip commit message validation with a warning - commit first, then re-run to validate.
+
+You can also run the commit message check independently:
+```
+python ops/lintcommit.py
+```
+
 ## Coding Standards
 Consistency is important for maintainability. Please adhere to the house-style of the repo, unless there's a really
 good reason to break pattern.

CONTRIBUTING.md

@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+
+import os
+import sys
+import unittest
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+from lintcommit import validate_message, validate_subject
+
+
+class TestValidateSubject(unittest.TestCase):
+    # Valid subjects
+    def test_valid_feat(self) -> None:
+        self.assertIsNone(validate_subject("feat: add new feature"))
+
+    def test_valid_fix(self) -> None:
+        self.assertIsNone(validate_subject("fix: resolve issue"))
+
+    def test_valid_fix_with_scope(self) -> None:
+        self.assertIsNone(validate_subject("fix(sdk): resolve issue"))
+
+    def test_valid_build(self) -> None:
+        self.assertIsNone(validate_subject("build: update build process"))
+
+    def test_valid_chore(self) -> None:
+        self.assertIsNone(validate_subject("chore: update dependencies"))
+
+    def test_valid_ci(self) -> None:
+        self.assertIsNone(validate_subject("ci: configure CI/CD"))
+
+    def test_valid_deps(self) -> None:
+        self.assertIsNone(validate_subject("deps: bump aws-sdk group with 5 updates"))
+
+    def test_valid_docs(self) -> None:
+        self.assertIsNone(validate_subject("docs: update documentation"))
+
+    def test_valid_feat_with_scope(self) -> None:
+        self.assertIsNone(validate_subject("feat(sdk): add new feature"))
+
+    def test_valid_feat_scope_bar(self) -> None:
+        self.assertIsNone(validate_subject("feat(sdk): bar"))
+
+    def test_valid_feat_foo(self) -> None:
+        self.assertIsNone(validate_subject("feat: foo"))
+
+    def test_valid_fix_foo(self) -> None:
+        self.assertIsNone(validate_subject("fix: foo"))
+
+    # Invalid subjects
+    def test_invalid_type(self) -> None:
+        self.assertEqual(validate_subject("config: foo"), 'invalid type "config"')
+
+    def test_missing_colon(self) -> None:
+        self.assertEqual(validate_subject("invalid title"), "missing colon (:) char")
+
+    def test_period_at_end(self) -> None:
+        self.assertEqual(
+            validate_subject("feat: add thing."),
+            "subject must not end with a period",
+        )
+
+    def test_empty_subject(self) -> None:
+        self.assertEqual(validate_subject("feat: "), "empty subject")
+
+    def test_subject_too_long(self) -> None:
+        long_subject: str = "feat: " + "a" * 51
+        result: str | None = validate_subject(long_subject)
+        self.assertIsNotNone(result)
+        self.assertIn("invalid subject", result)  # type: ignore[arg-type]
+
+    def test_type_with_whitespace(self) -> None:
+        self.assertEqual(
+            validate_subject("fe at: foo"), 'type contains whitespace: "fe at"'
+        )
+
+    def test_scope_not_closed(self) -> None:
+        self.assertEqual(
+            validate_subject("feat(sdk: foo"), "must be formatted like type(scope):"
+        )
+
+    def test_scope_too_long(self) -> None:
+        long_scope: str = "a" * 31
+        result: str | None = validate_subject(f"feat({long_scope}): foo")
+        self.assertIsNotNone(result)
+        self.assertIn("invalid scope", result)  # type: ignore[arg-type]
+
+    def test_scope_uppercase(self) -> None:
+        result: str | None = validate_subject("feat(SDK): foo")
+        self.assertIsNotNone(result)
+        self.assertIn("invalid scope", result)  # type: ignore[arg-type]
+
+
+class TestValidateMessage(unittest.TestCase):
+    def test_valid_subject_only(self) -> None:
+        error, warnings = validate_message("feat: add thing")
+        self.assertIsNone(error)
+        self.assertEqual(warnings, [])
+
+    def test_valid_with_body(self) -> None:
+        error, warnings = validate_message("feat: add thing\n\nThis is the body.")
+        self.assertIsNone(error)
+        self.assertEqual(warnings, [])
+
+    def test_missing_blank_line(self) -> None:
+        _, warnings = validate_message("feat: add thing\nNo blank line.")
+        self.assertIn("missing blank line between subject and body", warnings)
+
+    def test_long_body_line(self) -> None:
+        _, warnings = validate_message("feat: add thing\n\n" + "x" * 80)
+        self.assertEqual(len(warnings), 1)
+        self.assertIn("exceeds 72 chars", warnings[0])
+
+    def test_empty_message(self) -> None:
+        error, _ = validate_message("")
+        self.assertEqual(error, "empty commit message")
+
+    def test_invalid_subject_in_message(self) -> None:
+        error, _ = validate_message("invalid title")
+        self.assertEqual(error, "missing colon (:) char")

ops/__tests__/test_lintcommit.py

@@ -13,3 +13,6 @@ echo SUCCESS: typings
 # static analysis
 hatch fmt
 echo SUCCESS: linting/fmt
+
+# commit message validation
+python ops/lintcommit.py