Go testing with go test, testify, and gomock. Covers unit tests, table-driven
tests, benchmarks, mocking, and test coverage.
USE WHEN: user mentions "go test", "golang test", "testify", asks about "table-driven test", "gomock", "go benchmark", "testing.T", "httptest"
DO NOT USE FOR: JavaScript/TypeScript - use `vitest` or `jest`; Java - use `junit`; Python - use `pytest`; E2E browser tests - use Playwright; Rust - use `rust-testing`