design cancellable function core interview pattern Pattern
1 problems
Pattern pages help build reusable solving frames. Identify signals first, then explain state, transition, and edge handling.
Recognition Signals
- Expect candidates to recognize the two-way communication between generator and async evaluation.
- Watch for proper handling of promise rejections thrown back into the generator.
Solve Flow
- 1. Define the active state/window.
- 2. Update state while preserving invariants.
- 3. Validate with edge-heavy examples.
Common Misses
- Failing to propagate promise rejections back into the generator correctly.