golang-testing

Table-driven tests in Go use a struct slice to define inputs and expected outputs, iterating over them with subtests via t.Run to execute test cases and assert results systematically. This approach isolates test logic and clarifies failures.

Measure Go test coverage by invoking the test runner with coverage flags, and execute benchmarks using benchmark functions to capture performance metrics. Analyzing coverage ensures code paths are exercised, while benchmarks identify performance regressions.

Fuzzing in Go automatically generates random inputs to feed into test functions, continuously running the code to uncover edge cases and panics. It helps ensure your code handles unexpected input gracefully without explicitly defining every test case.

Mock dependencies in Go by defining interfaces for external interactions and creating mock implementations for tests. This allows you to isolate the unit under test, simulate error conditions, and verify behavior without relying on actual external services.

Golden files store expected output in separate files, allowing Go tests to compare actual results against these fixtures. This technique simplifies managing large or complex expected outputs, updating them by regenerating the golden files when behavior changes intentionally.

Apply Test-Driven Development by writing a failing test first, implementing the minimum code to pass it, and refactoring. For a Go API, this means defining endpoint behavior through tests, ensuring correctness under various scenarios before integration.