tools: add GitHub Action to ping code owners

.github/workflows/ping-code-owners.yml

@@ -0,0 +1,34 @@
+name: Ping Code Owners
+
+on:
+  pull_request_target:
+    types: [opened]
+
+permissions:
+  pull-requests: write
+  contents: read
+
+jobs:
+  ping-owners:
+    if: github.repository == 'nodejs/node'
+    runs-on: ubuntu-slim
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
+        with:
+          persist-credentials: false
+
+      - name: Use Node.js lts/*
+        uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e  # v6.4.0
+        with:
+          node-version: lts/*
+
+      - name: Install codeowners-utils
+        run: npm install --no-save codeowners-utils
+
+      - name: Ping code owners
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          REPO_OWNER: ${{ github.repository_owner }}
+          REPO_NAME: ${{ github.event.repository.name }}
+        run: node tools/actions/ping-owners.mjs

tools/actions/ping-owners.mjs

@@ -0,0 +1,72 @@
+import { matchPattern, parse } from 'codeowners-utils';
+import { readFileSync } from 'node:fs';
+
+const { GITHUB_TOKEN, PR_NUMBER, REPO_OWNER, REPO_NAME } = process.env;
+
+async function githubRequest(path, options = {}) {
+  const response = await fetch(`https://api.github.com${path}`, {
+    ...options,
+    headers: {
+      'Authorization': `Bearer ${GITHUB_TOKEN}`,
+      'Accept': 'application/vnd.github.v3+json',
+      'X-GitHub-Api-Version': '2022-11-28',
+      ...options.headers,
+    },
+  });
+  if (!response.ok) {
+    throw new Error(`GitHub API error: ${response.status} ${response.statusText}`);
+  }
+  return response.json();
+}
+
+async function getChangedFiles() {
+  const files = [];
+  let page = 1;
+  while (true) {
+    const data = await githubRequest(
+      `/repos/${REPO_OWNER}/${REPO_NAME}/pulls/${PR_NUMBER}/files?per_page=100&page=${page}`,
+    );
+    files.push(...data.map((f) => f.filename));
+    if (data.length < 100) break;
+    page++;
+  }
+  return files;
+}
+
+export function getOwnersForPaths(codeownersContent, changedFiles) {
+  const definitions = parse(codeownersContent);
+  let ownersForPaths = [];
+
+  for (const { pattern, owners } of definitions) {
+    for (const file of changedFiles) {
+      if (matchPattern(file, pattern)) {
+        ownersForPaths = ownersForPaths.concat(owners);
+      }
+    }
+  }
+
+  return ownersForPaths.filter((v, i) => ownersForPaths.indexOf(v) === i).sort();
+}
+
+export function getCommentBody(owners) {
+  return `Review requested:\n\n${owners.map((i) => `- [ ] ${i}`).join('\n')}`;
+}
+
+async function pingOwners() {
+  const changedFiles = await getChangedFiles();
+  const codeownersContent = readFileSync('.github/CODEOWNERS', 'utf8');
+  const owners = getOwnersForPaths(codeownersContent, changedFiles);
+  if (owners.length === 0) return;
+  await githubRequest(
+    `/repos/${REPO_OWNER}/${REPO_NAME}/issues/${PR_NUMBER}/comments`,
+    {
+      method: 'POST',
+      body: JSON.stringify({ body: getCommentBody(owners) }),
+    },
+  );
+}
+
+pingOwners().catch((err) => {
+  console.error(err);
+  process.exit(1);
+});