From a3fdc98ed7b72af30d2f05f43ec84586e9eda09d Mon Sep 17 00:00:00 2001
From: ymc9 <104139426+ymc9@users.noreply.github.com>
Date: Thu, 23 Jul 2026 22:34:36 +0800
Subject: [PATCH] fix(cli): prevent silent zero-exit when the version-check
 fetch stalls
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Every zen command awaits checkNewVersion() in a preAction hook, which
fetches the npm registry with AbortSignal.timeout(2000). If the
connection stalls in a way that strands the fetch promise with no
active handle, nothing keeps the event loop alive (AbortSignal.timeout's
timer is unref'd), so node exits with code 0 before the command's
action runs — the CLI reports success having done nothing.

On CI runners this struck roughly 1 in 100-300 invocations, which made
most Build-and-Test runs fail in a random packages/cli test with
baffling "output file missing after successful CLI run" assertions
(observed on PRs and on main alike; root-caused and fix verified over
several instrumented runs on the throwaway diagnostic PR #2766).

Fix: race the fetch against a ref'd, always-settling timer that is
cleared afterward. The timer keeps the event loop alive and guarantees
the await settles into the existing catch. A noop catch on the losing
fetch promise avoids unhandled rejections in long-lived modes (watch,
proxy, studio).

Also: runCli in the CLI test harness now captures and prints the
child's stdout/stderr when a command fails, so future failures of this
kind are self-diagnosing instead of bare assertion errors.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 packages/cli/src/utils/version-utils.ts | 18 +++++++++++++++++-
 packages/cli/test/utils.ts              | 11 ++++++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/packages/cli/src/utils/version-utils.ts b/packages/cli/src/utils/version-utils.ts
index e9749e878..25a257633 100644
--- a/packages/cli/src/utils/version-utils.ts
+++ b/packages/cli/src/utils/version-utils.ts
@@ -20,11 +20,27 @@ export function getVersion() {
 export async function checkNewVersion() {
     const currVersion = getVersion();
     let latestVersion: string;
+    // race against a ref'd, always-settling timer: if the fetch's connection dies in a
+    // way that strands its promise (leaving no active handle), the pending `await` would
+    // otherwise drain the event loop and silently exit the process with code 0 mid-command;
+    // the timer both keeps the loop alive and guarantees this await settles
+    let timer: NodeJS.Timeout | undefined;
     try {
-        latestVersion = await getLatestVersion();
+        const fetchPromise = getLatestVersion();
+        // if the timer wins the race, a later settlement of the fetch must not surface
+        // as an unhandled rejection
+        fetchPromise.catch(() => {});
+        latestVersion = await Promise.race([
+            fetchPromise,
+            new Promise<never>((_, reject) => {
+                timer = setTimeout(() => reject(new Error('version check timed out')), CHECK_VERSION_TIMEOUT + 1000);
+            }),
+        ]);
     } catch {
         // noop
         return;
+    } finally {
+        clearTimeout(timer);
     }
 
     if (latestVersion && currVersion && semver.gt(latestVersion, currVersion)) {
diff --git a/packages/cli/test/utils.ts b/packages/cli/test/utils.ts
index 85d85559b..799d16838 100644
--- a/packages/cli/test/utils.ts
+++ b/packages/cli/test/utils.ts
@@ -117,5 +117,14 @@ export async function createProject(
 
 export function runCli(command: string, cwd: string) {
     const cli = path.join(__dirname, '../dist/index.mjs');
-    execSync(`node ${cli} ${command}`, { cwd });
+    try {
+        return execSync(`node ${cli} ${command}`, { cwd, encoding: 'utf8' });
+    } catch (err: any) {
+        // surface the child's output in the test log — without this, CLI failures show up
+        // as bare assertion errors with no clue about what the CLI actually did
+        console.error(`[runCli] "${command}" failed in ${cwd} (status=${err.status}, signal=${err.signal})`);
+        console.error(`[runCli] stdout:\n${err.stdout}`);
+        console.error(`[runCli] stderr:\n${err.stderr}`);
+        throw err;
+    }
 }