01_builtin_testing

Built-in Testing Package

Go's standard testing package provides the foundation for all testing in Go. It's part of the standard library, requires no external dependencies, and is the basis for all other testing frameworks.

📦 Installation

No installation needed - it's part of Go's standard library!

🎯 Features

• Unit Testing: Write test functions with func TestXxx(t *testing.T)
• Benchmarking: Measure performance with func BenchmarkXxx(b *testing.B)
• Parallel Execution: Run tests concurrently with t.Parallel()
• Subtests: Organize tests hierarchically with t.Run()
• Table-Driven Tests: Test multiple scenarios efficiently
• Test Coverage: Built-in coverage analysis with -cover flag

📖 Usage

Basic Test

func TestSum(t *testing.T) {
    result := Sum(2, 3)
    if result != 5 {
        t.Errorf("Expected 5, got %d", result)
    }
}

Table-Driven Test

func TestSum(t *testing.T) {
    tests := []struct {
        name     string
        a, b     int
        expected int
    }{
        {"positive numbers", 2, 3, 5},
        {"negative numbers", -1, -2, -3},
        {"zero", 0, 0, 0},
    }

    for _, tt := range tests {
        t.Run(tt.name, func(t *testing.T) {
            result := Sum(tt.a, tt.b)
            if result != tt.expected {
                t.Errorf("Sum(%d, %d) = %d; want %d", 
                    tt.a, tt.b, result, tt.expected)
            }
        })
    }
}

🚀 Running Tests

# Run all tests
go test

# Run with verbose output
go test -v

# Run with coverage
go test -cover

# Run specific test
go test -run TestSum

# Run benchmarks
go test -bench=.

📊 Example Output

=== RUN   TestSum
=== RUN   TestSum/positive_numbers
=== RUN   TestSum/negative_numbers
=== RUN   TestSum/with_zero
--- PASS: TestSum (0.00s)
    --- PASS: TestSum/positive_numbers (0.00s)
    --- PASS: TestSum/negative_numbers (0.00s)
    --- PASS: TestSum/with_zero (0.00s)
PASS
ok      github.com/lirany1/go-testing-framework-examples/01_builtin_testing    0.002s

✅ Pros

• ✅ Part of Go standard library (no dependencies)
• ✅ Fast and lightweight
• ✅ Simple and straightforward
• ✅ Excellent IDE support
• ✅ Built-in benchmarking and profiling
• ✅ Native parallel test execution

❌ Cons

• ❌ No built-in assertion library (manual if checks)
• ❌ Not BDD-style
• ❌ Verbose for complex assertions
• ❌ No built-in mocking (need external tools)

🔗 Resources

• Official Documentation
• Go Testing Tutorial
• Table-Driven Tests in Go

💡 Best Practices

1. Use Table-Driven Tests: Test multiple scenarios efficiently
2. Name Tests Descriptively: Use TestFunctionName_Scenario pattern
3. Test One Thing: Each test should verify a single behavior
4. Use Subtests: Organize related tests with t.Run()
5. Check Coverage: Aim for meaningful coverage, not 100%