gpui-testing

Why: GPUI's scheduler tracks GPUI timers but not smol::Timer, which can cause "nothing left to run" errors in rununtilparked().

| Using smol::Timer | "Nothing left to run" | Use cx.backgroundexecutor.timer() | | Not calling rununtilparked() | Async work doesn't complete | Call before assertions | | Forgetting #[gpui::test] | Test doesn't run properly | Use #[gpui::test] attribute | Not handling errors in async | Test failures unclear | Propagate errors with ? |

| Testing too much at once | Hard to debug failures | Split into smaller tests |

Testing GPUI applications and components. Use when writing tests, testing async operations, simulating user input, or debugging test failures. Source: cnwzhu/gpui-skills.