golang-testing

name	golang-testing
description	Standards for unit testing, table-driven tests, and mocking in Golang. Use when writing Go unit tests, table-driven tests, or using mock interfaces. (triggers: **/*_test.go, testing, unit tests, go test, mocking, testify)

Golang Testing Standards

Priority: P0 (CRITICAL)

Guidelines

TDD & Table-Driven Tests

• Pattern: Use Table-Driven Tests for multi-input scenarios. Use t.Run() for each test case.
• Workflow: Follow Red-Green-Refactor. Write a failing test case before implementing logic.
• Mocking: Use Interfaces and Dependency Injection. Avoid complex mocking frameworks; prefer manual mocks or GoMock.
• Coverage: Aim for > 80% line coverage. Run go test -cover to audit.
• Assertions: Use testify/assert or testify/require for readable checks: assert.NoError(t, err).
• Parallelism: Use t.Parallel() for non-sequential tests to speed up CI.
• Cleanup: Use t.Cleanup() to reset state or release resources (DB/Files).
• Subtests: Name each subtest case clearly ("Valid input", "Missing ID", "Network timeout").

Golden Snippet

See Table-Driven Tests for full template.

Tools

• Stdlib: testing package is usually enough.
• Testify (stretchr/testify): Assertions (assert, require) and Mocks.
• Mockery: Auto-generate mocks for interfaces.
• GoMock: Another popular mocking framework.

Naming

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

Anti-Patterns

• No Manual Mocks: Use mockery for boilerplate-heavy mocks.
• No Assert in Loop: Use t.Run to isolate failures within table-driven loops.
• No Global Mocks: Define mocks locally or within test scope to avoid state leakage.

References

• Table-Driven Tests
• Mocking Strategies