fix(scripts): make checklist help exit cleanly (#3067)

Co-authored-by: Steven Enamakel <enamakel@tinyhumans.ai>

scripts/__tests__/check-pr-checklist.test.mjs

@@ -0,0 +1,31 @@
+import assert from 'node:assert/strict';
+import { spawnSync } from 'node:child_process';
+import { dirname, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { test } from 'node:test';
+
+const HERE = dirname(fileURLToPath(import.meta.url));
+const SCRIPT = resolve(HERE, '..', 'check-pr-checklist.mjs');
+
+function run(args, options = {}) {
+  return spawnSync(process.execPath, [SCRIPT, ...args], {
+    encoding: 'utf8',
+    ...options,
+  });
+}
+
+test('check-pr-checklist --help prints usage and exits 0', () => {
+  const result = run(['--help']);
+
+  assert.equal(result.status, 0, result.stderr);
+  assert.match(result.stdout, /Usage: check-pr-checklist\.mjs \[body-file\|-\]/);
+  assert.equal(result.stderr, '');
+});
+
+test('check-pr-checklist -h prints usage and exits 0', () => {
+  const result = run(['-h']);
+
+  assert.equal(result.status, 0, result.stderr);
+  assert.match(result.stdout, /Usage: check-pr-checklist\.mjs \[body-file\|-\]/);
+  assert.equal(result.stderr, '');
+});

scripts/check-pr-checklist.mjs

@@ -2,10 +2,18 @@
 import { readFileSync } from 'node:fs';
 import { parseChecklist, summarize } from './lib/checklist-parser.mjs';
 
+function usage() {
+  return 'Usage: check-pr-checklist.mjs [body-file|-]';
+}
+
 function readBody() {
   const [source, extra] = process.argv.slice(2);
+  if (source === '--help' || source === '-h') {
+    console.log(usage());
+    process.exit(0);
+  }
   if (extra) {
-    console.error('Usage: check-pr-checklist.mjs [body-file|-]');
+    console.error(usage());
     process.exit(2);
   }
   if (source === '-') {