From 42d336baa4342458f9623a13ea37272660d4021a Mon Sep 17 00:00:00 2001
From: Anthony Ettinger <anthony@chovy.com>
Date: Sat, 29 Aug 2026 11:20:40 +0000
Subject: [PATCH] test: stop the paired-mousemove test racing a 16ms wall-clock
 window

`usePointerLock` suppresses the mousemove that Chromium pairs with a
pointermove by checking `performance.now() - lastPointerMoveAt < 16`. The test
dispatches the pair on consecutive lines and expects the second to be dropped.

That makes real elapsed time part of the assertion. On a loaded CI runner more
than 16ms can pass between those two dispatches, the mousemove is taken as a
second movement, and the pointer reads 0.7 instead of 0.6 -- a red build with
nothing wrong in the code. It failed exactly this way on PR #87, which touches
only apps/desktop, while the identical desktop copy of the test passed in the
same run.

Freezes performance.now across the paired dispatch in both copies. Confirmed by
running the same test with a clock stepping 20ms per call, which reproduces the
CI diff exactly (0.7 vs 0.6). Nothing that ships changes -- the 16ms window is
still the shipped behaviour, it just is not a race in the test any more.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013FGWJHRL6B6ExLg25UenBS
---
 .../components/control/InputCapture.test.tsx  | 28 +++++++++++++------
 .../components/control/InputCapture.test.tsx  | 28 +++++++++++++------
 2 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/apps/desktop/src/renderer/components/control/InputCapture.test.tsx b/apps/desktop/src/renderer/components/control/InputCapture.test.tsx
index 0be006a8..3e735d18 100644
--- a/apps/desktop/src/renderer/components/control/InputCapture.test.tsx
+++ b/apps/desktop/src/renderer/components/control/InputCapture.test.tsx
@@ -198,6 +198,13 @@ describe('InputCapture pointer lock', () => {
     );
   });
 
+  // The paired mousemove is suppressed by a 16ms window on performance.now(),
+  // so the real wall-clock gap between the two dispatches below decides the
+  // outcome. On a loaded machine that gap can exceed 16ms, the mousemove lands
+  // as a second movement, and the pointer reads 0.7 instead of 0.6 -- a flaky
+  // test rather than a regression. Freeze the clock across the pair so the
+  // window is not a race. Only these two dispatches are covered; everything
+  // else in the test still runs on real time.
   it('does not count a paired mousemove twice after pointermove', () => {
     const browser = installBrowserApis();
     const onInputEvent = vi.fn();
@@ -208,14 +215,19 @@ describe('InputCapture pointer lock', () => {
       browser.grantLock(container);
     });
 
-    act(() => {
-      document.dispatchEvent(
-        Object.assign(new MouseEvent('pointermove'), { movementX: 100, movementY: 50 })
-      );
-      document.dispatchEvent(
-        Object.assign(new MouseEvent('mousemove'), { movementX: 100, movementY: 50 })
-      );
-    });
+    const now = vi.spyOn(performance, 'now').mockReturnValue(1000);
+    try {
+      act(() => {
+        document.dispatchEvent(
+          Object.assign(new MouseEvent('pointermove'), { movementX: 100, movementY: 50 })
+        );
+        document.dispatchEvent(
+          Object.assign(new MouseEvent('mousemove'), { movementX: 100, movementY: 50 })
+        );
+      });
+    } finally {
+      now.mockRestore();
+    }
 
     onInputEvent.mockClear();
     act(() => {
diff --git a/apps/web/src/components/control/InputCapture.test.tsx b/apps/web/src/components/control/InputCapture.test.tsx
index 0be006a8..3e735d18 100644
--- a/apps/web/src/components/control/InputCapture.test.tsx
+++ b/apps/web/src/components/control/InputCapture.test.tsx
@@ -198,6 +198,13 @@ describe('InputCapture pointer lock', () => {
     );
   });
 
+  // The paired mousemove is suppressed by a 16ms window on performance.now(),
+  // so the real wall-clock gap between the two dispatches below decides the
+  // outcome. On a loaded machine that gap can exceed 16ms, the mousemove lands
+  // as a second movement, and the pointer reads 0.7 instead of 0.6 -- a flaky
+  // test rather than a regression. Freeze the clock across the pair so the
+  // window is not a race. Only these two dispatches are covered; everything
+  // else in the test still runs on real time.
   it('does not count a paired mousemove twice after pointermove', () => {
     const browser = installBrowserApis();
     const onInputEvent = vi.fn();
@@ -208,14 +215,19 @@ describe('InputCapture pointer lock', () => {
       browser.grantLock(container);
     });
 
-    act(() => {
-      document.dispatchEvent(
-        Object.assign(new MouseEvent('pointermove'), { movementX: 100, movementY: 50 })
-      );
-      document.dispatchEvent(
-        Object.assign(new MouseEvent('mousemove'), { movementX: 100, movementY: 50 })
-      );
-    });
+    const now = vi.spyOn(performance, 'now').mockReturnValue(1000);
+    try {
+      act(() => {
+        document.dispatchEvent(
+          Object.assign(new MouseEvent('pointermove'), { movementX: 100, movementY: 50 })
+        );
+        document.dispatchEvent(
+          Object.assign(new MouseEvent('mousemove'), { movementX: 100, movementY: 50 })
+        );
+      });
+    } finally {
+      now.mockRestore();
+    }
 
     onInputEvent.mockClear();
     act(() => {