testing

Table-driven tests in Go organize multiple test cases into a slice of structs, each containing inputs and expected outputs. This pattern reduces code duplication, improves readability, and systematically covers edge cases by iterating through all scenarios in a single test function, making regression detection more reliable.

A test contract explicitly documents inputs, outputs, and side effects for each test case. This pre-flight checklist ensures clarity about what your test validates, prevents ambiguous assertions, and helps catch unintended behaviors before they cause regressions in production.

Realistic test data mirrors production conditions rather than using dummy values. The skill guides selecting representative samples, edge-case boundaries, and error scenarios that reflect actual usage patterns, improving test reliability and regression detection across diverse code paths.

Test helpers extract common setup, assertions, and cleanup logic into reusable functions. They improve consistency across tests, reduce boilerplate, and make test suites easier to maintain—when helper behavior changes, all dependent tests benefit from the fix without individual updates.

Yes. The `-race` flag detects data races at runtime during test execution. Running `go test -race ./...` catches concurrent access bugs that standard tests miss, significantly improving reliability and preventing hard-to-debug production failures.

Explicitly test both success and failure paths for each function. Table-driven tests make it straightforward to include error cases as separate rows with expected error values, ensuring comprehensive coverage that catches regressions in error handling logic.