Golang Testing

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 slice of structs; iterate with t.Run().
3. Zero Volatile Fields for Struct Comparison — When asserting struct equality, zero out timestamps, dynamic IDs, or generated tokens before assert.Equal to prevent flaky assertions.
4. Mock via interfaces — Use DI and interfaces. Prefer mockery for auto-generated mocks or manual mocks for simple cases.
5. Run parallel — Use t.Parallel() for non-sequential tests to speed up CI.
6. Clean up resources — Use t.Cleanup() to restore state or release DB/file resources.
7. Check coverage — Aim for >80% line coverage. Run go test -cover to audit.

See table-driven test examples

Tools

• Stdlib: testing package 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

• No assert in loops: use t.Run subtests to isolate failures.
• No brittle assertions on volatile fields: avoid matching exact timestamps or non-deterministic IDs without normalization.
• No global mock state: define mocks locally within test scope.
• No skipping race detection: always run go test -race in CI.

References

• Table-Driven Tests
• Mocking Strategies