Rewrite the PR commit linter job in CI

The action this was using previously is gone now.

Author: friendlyanon

.github/scripts/lint-commits.js

@@ -55,44 +55,44 @@ const checkers = [{
   },
 }];
 
-async function readJsonFromStdin() {
-  const chunks = [];
-  for await (const chunk of process.stdin) {
-    chunks.push(chunk);
-  }
-
-  return Buffer.concat(chunks).toString();
-}
-
 function runChecker({ check, error }) {
   return check(this.message) ? [] : [error];
 }
 
-async function main() {
-  const commits = JSON.parse(await readJsonFromStdin());
-
-  let exitCode = 0;
+function checkCommits(commits) {
+  let success = true;
   for (const { commit, sha } of commits) {
     const errors = checkers.flatMap(runChecker, commit);
     if (errors.length === 0) {
       continue;
     }
 
-    if (exitCode !== 0) {
+    if (!success) {
       console.log("");
     }
-    exitCode = 1;
+    success = false;
 
     console.log("Commit %s failed these checks:", sha);
     for (const error of errors) {
       console.log("  %s", error);
     }
   }
 
-  return exitCode;
+  return success;
+}
+
+async function main(github, core, context) {
+  const { repository, pull_request } = context.payload;
+  const options = github.rest.pulls.listCommits.endpoint.merge({
+    owner: repository.owner.login,
+    repo: repository.name,
+    pull_number: pull_request.number,
+  });
+  const commits = await github.paginate(options);
+  const isErrorFree = checkCommits(commits);
+  if (!isErrorFree) {
+    core.setFailed("Please check the logs for errors in commit messages.");
+  }
 }
 
-main().catch((error) => {
-  console.error(error);
-  return 1;
-}).then((code) => { process.exitCode = code; });
+module.exports = { main };

.github/workflows/lint-commits.yml

@@ -12,13 +12,10 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - name: Get PR commits
-      id: commits
-      uses: IdanHo/get-pr-commits@d94b66d146a31ef91e54a2597dee4fb523157232
-      with: { token: "${{ github.token }}" }
+    - uses: actions/checkout@v2
 
     - name: Check commits
-      run: |
-        node .github/scripts/lint-commits.js << 'JSON'
-        ${{ steps.commits.outputs.commits }}
-        JSON
+      uses: actions/github-script@v5
+      with:
+        script: await require(".github/scripts/lint-commits.js")
+          .main(github, core, context)