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test/capture.mjs

@@ -65,7 +65,12 @@ function startProc(cmd, procArgs, env, tag) {
     cwd: FRONT_ROOT,
     env: { ...process.env, ...env },
     stdio: ['ignore', 'pipe', 'pipe'],
+    // Own process group per child so stopProc can kill the whole tree
+    // (e.g. `npx vite` wrapper + the real vite process).
+    detached: process.platform !== 'win32',
   });
+  // Piped stdio keeps the parent alive even after kill(); detach the streams
+  // so teardown below can actually exit.
   child.stdout.on('data', (d) => process.stdout.write(`[${tag}] ${d}`));
   child.stderr.on('data', (d) => {
     const text = String(d);
@@ -73,9 +78,55 @@ function startProc(cmd, procArgs, env, tag) {
     if (tag === 'vite' && text.includes('[vite-proxy]')) return;
     process.stderr.write(`[${tag}] ${d}`);
   });
+  child.stdout.unref?.();
+  child.stderr.unref?.();
+  child.unref?.();
   return child;
 }
 
+async function stopProc(child, tag, timeoutMs = 8000) {
+  if (!child || child.exitCode != null || child.signalCode != null) return;
+  // Kill the whole process group (child + grandchildren like npx/vite).
+  const killTree = (sig) => {
+    try {
+      if (child.pid && process.platform !== 'win32') {
+        process.kill(-child.pid, sig);
+        return;
+      }
+    } catch {
+      // fall through to single kill
+    }
+    try {
+      child.kill(sig);
+    } catch {
+      // already gone
+    }
+  };
+  await new Promise((resolve) => {
+    const timer = setTimeout(() => {
+      killTree('SIGKILL');
+      resolve();
+    }, timeoutMs);
+    timer.unref?.();
+    child.once('exit', () => {
+      clearTimeout(timer);
+      resolve();
+    });
+    killTree('SIGTERM');
+  });
+  // Drain any buffered pipe listeners so they can't hold the loop open.
+  try {
+    child.stdout?.destroy();
+  } catch {
+    // ignore
+  }
+  try {
+    child.stderr?.destroy();
+  } catch {
+    // ignore
+  }
+}
+
 async function main() {
   if (!fs.existsSync(CHROME)) {
     throw new Error(`Chrome not found at ${CHROME} (pass --chrome=...)`);
@@ -135,15 +186,18 @@ async function main() {
       }
     }
   } finally {
-    chrome.kill();
+    await stopProc(chrome, 'chrome');
-    vite.kill();
+    await stopProc(vite, 'vite');
-    dummy.kill();
+    await stopProc(dummy, 'dummy');
   }
   if (failed > 0) {
     console.error(`[capture] ${failed} shots failed`);
     process.exit(1);
   }
   console.log(`[capture] done → ${OUT_DIR}`);
+  // Explicit exit: spawned grandchildren (vite/esbuild, chrome helpers) can
+  // otherwise keep the event loop alive after teardown.
+  process.exit(0);
 }
 
 main().catch((err) => {

test/cdp.mjs

@@ -89,14 +89,25 @@ class CdpConnection {
   send(method, params = {}, timeoutMs = 30000) {
     const callId = ++this.id;
     return new Promise((resolve, reject) => {
-      this.pending.set(callId, { resolve, reject });
+      const timer = setTimeout(() => {
-      this.sendFrame(0x1, Buffer.from(JSON.stringify({ id: callId, method, params })));
-      setTimeout(() => {
         if (this.pending.has(callId)) {
           this.pending.delete(callId);
           reject(new Error(`CDP timeout: ${method}`));
         }
       }, timeoutMs);
+      // Don't let a settled call's timer hold the process open.
+      timer.unref?.();
+      this.pending.set(callId, {
+        resolve: (v) => {
+          clearTimeout(timer);
+          resolve(v);
+        },
+        reject: (e) => {
+          clearTimeout(timer);
+          reject(e);
+        },
+      });
+      this.sendFrame(0x1, Buffer.from(JSON.stringify({ id: callId, method, params })));
     });
   }