test: persist fake app-server lifecycle markers synchronously

Author: vitry

tests/codex-app-server.test.mjs

@@ -40,6 +40,12 @@ test('uses codex app-server and a 15 second deadline by default', async () => {
   assert.equal(CODEX_APP_SERVER_DEFAULT_TIMEOUT_MS, 15_000);
 });
 
+test('fake app-server persists lifecycle markers synchronously before exiting', async () => {
+  const source = await readFile(fake, 'utf8');
+  assert.match(source, /appendFileSync/);
+  assert.match(source, /recordLifecycle/);
+});
+
 test('terminates the child on success, JSON-RPC error, malformed output, oversized line and timeout', async (t) => {
   /** @type {Array<[Record<string,string>,Record<string,number>,string|null]>} */ const cases = [
     [{}, {}, null],

tests/fixtures/fake-codex-app-server.mjs

@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 // @ts-nocheck
+import { appendFileSync } from 'node:fs';
 import { appendFile } from 'node:fs/promises';
 import process from 'node:process';
 import readline from 'node:readline';
@@ -9,6 +10,9 @@ const input = readline.createInterface({ input: process.stdin, crlfDelay: Infini
 async function record(value) {
   if (process.env.FAKE_CODEX_RECORD) await appendFile(process.env.FAKE_CODEX_RECORD, `${JSON.stringify(value)}\n`);
 }
+function recordLifecycle(signal) {
+  if (process.env.FAKE_CODEX_RECORD) appendFileSync(process.env.FAKE_CODEX_RECORD, `${JSON.stringify({ lifecycle: signal })}\n`);
+}
 
 let outputQueue = Promise.resolve();
 function write(value) {
@@ -32,8 +36,8 @@ if (process.env.FAKE_CODEX_STDERR_BYTES) {
   process.stderr.write(text.repeat(Math.ceil(Number(process.env.FAKE_CODEX_STDERR_BYTES) / text.length)));
 }
 
-for (const signal of ['SIGTERM', 'SIGINT']) process.on(signal, async () => {
-  await record({ lifecycle: signal });
+for (const signal of ['SIGTERM', 'SIGINT']) process.on(signal, () => {
+  recordLifecycle(signal);
   process.exit(0);
 });
 process.on('exit', () => { if (process.env.FAKE_CODEX_EXIT_MARKER) process.stderr.write(process.env.FAKE_CODEX_EXIT_MARKER); });