test: watchdog E2E in 1.5s instead of 22.7s (tunable poll interval)

server.ts gains BROWSE_WATCHDOG_INTERVAL_MS (floor 50ms, default 15s
unchanged). The #994 stay-alive test runs a 250ms tick and waits for the
stay-alive log line instead of blind-sleeping 2s + 20s past the
production interval.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

browse/src/server.ts

@@ -696,6 +696,13 @@ const BROWSE_PARENT_PID = parseInt(process.env.BROWSE_PARENT_PID || '0', 10);
 // the closure every 15s. The CLI's connect path sets BROWSE_HEADED=1 + PID=0,
 // so this branch is the normal path for /open-gstack-browser.
 const IS_HEADED_WATCHDOG = process.env.BROWSE_HEADED === '1';
+// Poll interval is env-tunable so the watchdog E2E test can use a ~250ms tick
+// instead of waiting out the production 15s interval (was a 20s blind sleep).
+// Floor of 50ms guards against a typo'd 0 busy-looping the server.
+const WATCHDOG_INTERVAL_MS = (() => {
+  const raw = parseInt(process.env.BROWSE_WATCHDOG_INTERVAL_MS || '', 10);
+  return Number.isFinite(raw) && raw >= 50 ? raw : 15_000;
+})();
 if (BROWSE_PARENT_PID > 0 && !IS_HEADED_WATCHDOG) {
   let parentGone = false;
   setInterval(() => {
@@ -723,7 +730,7 @@ if (BROWSE_PARENT_PID > 0 && !IS_HEADED_WATCHDOG) {
         console.log(`[browse] Parent process ${BROWSE_PARENT_PID} exited (server stays alive, idle timeout will clean up)`);
       }
     }
-  }, 15_000);
+  }, WATCHDOG_INTERVAL_MS);
 } else if (IS_HEADED_WATCHDOG) {
   console.log('[browse] Parent-process watchdog disabled (headed mode)');
 } else if (BROWSE_PARENT_PID === 0) {

browse/test/watchdog.test.ts

@@ -25,8 +25,9 @@ import * as os from 'os';
 // /pair-agent users (server lingers after disconnect).
 //
 // Each test spawns the real server.ts. Tests 1 and 2 verify behavior via
-// stdout log line (fast). Test 3 waits for the watchdog poll cycle to confirm
+// stdout log line (fast). Test 3 shrinks the watchdog tick to 250ms via
-// the server REMAINS alive after parent death (slow — ~20s observation window).
+// BROWSE_WATCHDOG_INTERVAL_MS and waits for the stay-alive log line, then
+// confirms the server survived parent death (~1-2s instead of a 20s sleep).
 
 const ROOT = path.resolve(import.meta.dir, '..');
 const SERVER_SCRIPT = path.join(ROOT, 'src', 'server.ts');
@@ -137,21 +138,26 @@ describe('parent-process watchdog (v0.18.1.0)', () => {
     const parentPid = parentProc.pid!;
 
     // Default headless: no BROWSE_HEADED, real parent PID — watchdog active.
-    serverProc = spawnServer({ BROWSE_PARENT_PID: String(parentPid) }, 34903);
+    // 250ms tick (test-only knob) so this test doesn't wait out the
+    // production 15s interval; the old version blind-slept 22s.
+    serverProc = spawnServer(
+      { BROWSE_PARENT_PID: String(parentPid), BROWSE_WATCHDOG_INTERVAL_MS: '250' },
+      34903,
+    );
     const serverPid = serverProc.pid!;
 
-    // Give the server a moment to start and register the watchdog interval.
+    // Give the server a beat to register the watchdog interval.
-    await Bun.sleep(2000);
+    await Bun.sleep(500);
     expect(isProcessAlive(serverPid)).toBe(true);
 
-    // Kill the parent. The watchdog polls every 15s, so first tick after
+    // Kill the parent. Pre-#994 the server would shut down on the next tick.
-    // parent death lands within ~15s. Pre-#994 the server would shutdown
+    // Post-#994 it logs the parent exit and stays alive — wait for that log
-    // here. Post-#994 the server logs the parent exit and stays alive.
+    // line instead of sleeping past a fixed interval.
     parentProc.kill('SIGKILL');
-
+    const out = await readStdoutUntil(serverProc, 'server stays alive', 10_000);
-    // Wait long enough for at least one watchdog tick (15s) plus margin.
+    expect(out).toContain(
-    // Server should still be alive — that's the whole point of #994.
+      `Parent process ${parentPid} exited (server stays alive, idle timeout will clean up)`,
-    await Bun.sleep(20_000);
+    );
     expect(isProcessAlive(serverPid)).toBe(true);
-  }, 45_000);
+  }, 30_000);
 });