golang-testing

# Go Testing Patterns Comprehensive Go testing patterns for writing reliable, maintainable tests following TDD methodology. ## When to Activate - Writing new Go functions or methods - Adding test coverage to existing code - Creating benchmarks for performance-critical code - Implementing fuzz tests for input validation - Following TDD workflow in Go projects ## TDD Workflow for Go ### The RED-GREEN-REFACTOR Cycle ``` RED → Write a failing test first GREEN → Write minimal code to pass the test REFACTOR → Improve code while keeping tests green REPEAT → Continue with next requirement ``` ### Step-by-Step TDD in Go ```go // Step 1: Define the interface/signature // calculator.go package calculator func Add(a, b int) int { panic("not implemented") // Placeholder } // Step 2: Write failing test (RED) // calculator_test.go package calculator import "testing" func TestAdd(t *testing.T) { got := Add(2, 3) want := 5 if got != want { t.Errorf("Add(2, 3) = %d; want %d", got, want) } } // Step 3: Run test - verify FAIL // $ go test // --- FAIL: TestAdd (0.00s) // panic: not implemented // Step 4: Implement minimal code (GREEN) func Add(a, b int) int { return a + b } // Step 5: Run test - verify PASS // $ go test // PASS // Step 6: Refactor if needed, verify tests still pass ``` ## Table-Driven Tests The standard pattern for Go tests. Enables comprehensive coverage with minimal code. ```go func TestAdd(t *testing.T) { tests := [...