chore(codex): bootstrap PR for issue #153

.github/scripts/__tests__/agents-guard.test.js

@@ -0,0 +1,229 @@
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const { evaluateGuard, validatePullRequestTargetSafety } = require('../agents-guard');
+
+const protectedFile = {
+  filename: '.github/workflows/agents-foo.yml',
+  status: 'modified',
+};
+
+const codeownersContent = '.github/workflows/agents-foo.yml @owner';
+
+test('blocks protected workflow edits without label or approval', () => {
+  const result = evaluateGuard({
+    files: [protectedFile],
+    codeownersContent,
+    authorLogin: 'someone',
+  });
+
+  assert.equal(result.blocked, true);
+  assert.equal(result.needsLabel, true);
+  assert.equal(result.needsApproval, true);
+  assert.equal(result.hasAllowLabel, false);
+  assert.ok(result.failureReasons.some((reason) => reason.includes('Missing `agents:allow-change` label.')));
+  assert.ok(result.failureReasons.some((reason) => reason.includes('@owner')));
+});
+
+test('blocks protected edits with a comment body that lists next steps', () => {
+  const result = evaluateGuard({
+    files: [protectedFile],
+    codeownersContent,
+    authorLogin: 'someone',
+  });
+
+  assert.ok(result.commentBody);
+  assert.ok(result.commentBody.startsWith(result.marker));
+  assert.ok(result.commentBody.includes('**Next steps**'));
+  assert.ok(result.commentBody.includes('Apply the `agents:allow-change` label'));
+  assert.ok(result.commentBody.includes('Ask a CODEOWNER'));
+  assert.ok(result.commentBody.includes('.github/workflows/agents-foo.yml (modified)'));
+});
+
+test('allows protected workflow edits when the author is a codeowner', () => {
+  const result = evaluateGuard({
+    files: [protectedFile],
+    codeownersContent,
+    authorLogin: 'owner',
+  });
+
+  assert.equal(result.blocked, false);
+  assert.equal(result.hasCodeownerApproval, true);
+  assert.equal(result.needsLabel, false);
+  assert.equal(result.needsApproval, false);
+});
+
+test('allows protected workflow edits with codeowner review approval', () => {
+  const result = evaluateGuard({
+    files: [protectedFile],
+    codeownersContent,
+    authorLogin: 'someone',
+    reviews: [{
+      user: { login: 'owner' },
+      state: 'APPROVED',
+    }],
+  });
+
+  assert.equal(result.blocked, false);
+  assert.equal(result.hasCodeownerApproval, true);
+  assert.equal(result.needsLabel, false);
+  assert.equal(result.needsApproval, false);
+  assert.equal(result.hasAllowLabel, false);
+});
+
+test('treats allow-change labels as case-insensitive', () => {
+  const result = evaluateGuard({
+    files: [protectedFile],
+    codeownersContent,
+    authorLogin: 'someone',
+    labels: [{ name: 'Agents:Allow-Change' }],
+    reviews: [{
+      user: { login: 'owner' },
+      state: 'APPROVED',
+    }],
+  });
+
+  assert.equal(result.blocked, false);
+  assert.equal(result.hasAllowLabel, true);
+  assert.equal(result.hasCodeownerApproval, true);
+});
+
+test('blocks deletion of protected workflows that are not allowlisted', () => {
+  const result = evaluateGuard({
+    files: [{
+      filename: '.github/workflows/agents-foo.yml',
+      status: 'removed',
+    }],
+  });
+
+  assert.equal(result.blocked, true);
+  assert.ok(result.fatalViolations.some((reason) => reason.includes('was deleted')));
+});
+
+test('blocks renames of protected workflows that are not allowlisted', () => {
+  const result = evaluateGuard({
+    files: [{
+      filename: '.github/workflows/agents-foo-new.yml',
+      previous_filename: '.github/workflows/agents-foo.yml',
+      status: 'renamed',
+    }],
+  });
+
+  assert.equal(result.blocked, true);
+  assert.ok(result.fatalViolations.some((reason) => reason.includes('was renamed')));
+});
+
+test('allows removal of allowlisted workflow paths', () => {
+  const result = evaluateGuard({
+    files: [{
+      filename: '.github/workflows/agents-75-keepalive-on-gate.yml',
+      status: 'removed',
+    }],
+  });
+
+  assert.equal(result.blocked, false);
+  assert.equal(result.fatalViolations.length, 0);
+});
+
+test('does not allow label-only bypass without codeowner approval', () => {
+  const result = evaluateGuard({
+    files: [protectedFile],
+    codeownersContent,
+    labels: [{ name: 'agents:allow-change' }],
+    authorLogin: 'someone',
+  });
+
+  assert.equal(result.blocked, true);
+  assert.equal(result.hasAllowLabel, true);
+  assert.equal(result.needsApproval, true);
+  assert.ok(result.failureReasons.some((reason) => reason.includes('Request approval from a CODEOWNER')));
+});
+
+test('requires explicit approval when codeowners only list a team', () => {
+  const result = evaluateGuard({
+    files: [protectedFile],
+    codeownersContent: '.github/workflows/agents-foo.yml @octo/security',
+    labels: [{ name: 'agents:allow-change' }],
+    authorLogin: 'someone',
+  });
+
+  assert.equal(result.blocked, true);
+  assert.equal(result.hasAllowLabel, true);
+  assert.equal(result.needsApproval, true);
+  assert.ok(result.failureReasons.some((reason) => reason.includes('Request approval from a CODEOWNER.')));
+});
+
+test('validatePullRequestTargetSafety skips checks for non pull_request_target events', () => {
+  const result = validatePullRequestTargetSafety({
+    eventName: 'pull_request',
+    fsModule: {
+      readFileSync() {
+        throw new Error('unexpected read');
+      },
+    },
+  });
+
+  assert.deepEqual(result, { checked: false, violations: [] });
+});
+
+test('validatePullRequestTargetSafety blocks unsafe checkout and secrets usage', () => {
+  const workflowSource = [
+    'on: pull_request_target',
+    'jobs:',
+    '  test:',
+    '    runs-on: ubuntu-latest',
+    '    steps:',
+    '      - uses: actions/checkout@v4',
+    '        with:',
+    '          ref: ${{ github.event.pull_request.head.sha }}',
+    '      - run: |',
+    '          echo ${{ secrets.MY_SECRET }}',
+  ].join('\n');
+
+  assert.throws(
+    () => validatePullRequestTargetSafety({
+      eventName: 'pull_request_target',
+      workflowPath: '.github/workflows/agents-guard.yml',
+      workspaceRoot: process.cwd(),
+      fsModule: { readFileSync: () => workflowSource },
+    }),
+    /Unsafe pull_request_target usage detected/,
+  );
+});
+
+test('validatePullRequestTargetSafety allows safe pull_request_target workflow', () => {
+  const workflowSource = [
+    'on: pull_request_target',
+    'jobs:',
+    '  test:',
+    '    runs-on: ubuntu-latest',
+    '    steps:',
+    '      - uses: actions/checkout@v4',
+    '        with:',
+    '          fetch-depth: 1',
+    '      - run: echo "hello"',
+  ].join('\n');
+
+  const result = validatePullRequestTargetSafety({
+    eventName: 'pull_request_target',
+    workflowPath: '.github/workflows/agents-guard.yml',
+    workspaceRoot: process.cwd(),
+    fsModule: { readFileSync: () => workflowSource },
+  });
+
+  assert.deepEqual(result, { checked: true, violations: [] });
+});
+
+test('validatePullRequestTargetSafety throws when workflow file cannot be read', () => {
+  assert.throws(
+    () => validatePullRequestTargetSafety({
+      eventName: 'pull_request_target',
+      workflowPath: '.github/workflows/agents-guard.yml',
+      workspaceRoot: process.cwd(),
+      fsModule: { readFileSync: () => { throw new Error('no access'); } },
+    }),
+    /Failed to read \.github\/workflows\/agents-guard\.yml: no access/,
+  );
+});