Golang Testing

Priority: P0 (CRITICAL)

Implementation Workflow

1. Write failing test first — Follow Red-Green-Refactor TDD workflow.
2. Use table-driven tests — Define test cases as a slice of structs; iterate with t.Run().
3. Mock via interfaces — Use DI and interfaces. Prefer mockery for auto-generated mocks or manual mocks for simple cases.
4. Run parallel — Use t.Parallel() for non-sequential tests to speed up CI.
5. Clean up resources — Use t.Cleanup() to reset state or release DB/file resources.
6. Check coverage — Aim for >80% line coverage. Run go test -cover to audit.

See table-driven test examples

Tools

• Stdlib: testing package is usually enough.
• Testify: Assertions (assert, require) and mocks.
• Mockery: Auto-generate mocks for interfaces.
• GoMock: Popular mocking framework alternative.

Naming

• Test file: *_test.go
• Test function: func TestName(t *testing.T)
• Example function: func ExampleName()

Anti-Patterns

• ❌ assert inside loops without t.Run — use subtests to isolate failures
• ❌ Global mock state — define mocks locally within test scope
• ❌ Skipping race detection — always run go test -race in CI

References

• Table-Driven Tests
• Mocking Strategies