test(server): isolate cold Git filter from control work

2026-10-31 21:52:54 +00:00 · 2026-10-31 21:04:16 +00:00
1 changed files with 8 additions and 2 deletions
@@ -583,16 +583,21 @@ test("Git refresh, command tracing and 10,000 ignored alias events do no synchro
      // the cold filter. Allocations made by the filter still count.
      global.gc();
      await tick();
-      // Unrelated callbacks must not consume the synchronous filter's budget.
+      await marker('FILTER_START');
+      // Schedule the control only after marker IO settles, so it cannot run
+      // and allocate garbage before the cold filter starts. No await may
+      // separate this scheduling from the synchronous measurement.
      const threadCpuUsage = Reflect.get(process, 'threadCpuUsage');
+      let unrelatedWorkStarted = false;
      const unrelatedWork = tick().then(() => {
+        unrelatedWorkStarted = true;
        const started = threadCpuUsage();
        while (true) {
          const cpu = threadCpuUsage(started);
          if (cpu.user + cpu.system >= 80000) break;
        }
      });
-      await marker('FILTER_START');
+      assert.equal(unrelatedWorkStarted, false, 'control work must not contaminate the cold filter');
      hook.enable();
      let blockingMs;
      try {
@@ -609,6 +614,7 @@ test("Git refresh, command tracing and 10,000 ignored alias events do no synchro
        await marker('FILTER_END');
      }
      await unrelatedWork;
+      assert.equal(unrelatedWorkStarted, true, 'control work must run outside the filter span');
      assert.equal(fsCalls, 0, "filesystem calls");
      assert.equal(notifications, 0, "ignored event notification");
      assert.ok(blockingMs < 20, 'blocking filter work: ' + blockingMs);