How would you test Decorators?

Answers use simple, clear English.

Quick interview answer

Test Decorators with unit checks for the happy path, integration tests for real I/O boundaries, and load/chaos checks so regressions show up before prod. Core idea: Common mistakes: Forgetting @wraps; decorator not returning wrapper function. Best practices: Use wraps; accept *args/**kwargs in generic decorators; prefer parameterized factory pattern.

Detailed answer

Interview answer for testing Decorators: 1) Unit: isolate the pure logic behind Decorators with deterministic fixtures. 2) Integration: exercise real timers/I/O/network boundaries the way production does. 3) Load & soak: prove the event path still meets SLOs under concurrency. 4) Failure injection: break dependencies and assert recovery/backpressure. Best practices to include: Use wraps; accept *args/**kwargs in generic decorators; prefer parameterized factory pattern. Call out mistakes: Forgetting @wraps; decorator not returning wrapper function. Parent context: Common mistakes: Forgetting @wraps; decorator not returning wrapper function. Best practices: Use wraps; accept *args/**kwargs in generic decorators; prefer parameterized factory pattern.

Full explanation

Interviewers want a test strategy, not “I would write tests.” Tie each layer back to how Decorators fails: correctness, latency, and starvation. Decorators wrap functions: @decorator applies decorator(func). functools.wraps preserves __name__/__doc__. Common for logging, auth, caching, retries.

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Parent context — Decorators

Common mistakes: Forgetting @wraps; decorator not returning wrapper function. Best practices: Use wraps; accept *args/**kwargs in generic decorators; prefer parameterized factory pattern.

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