Testing

Testing in Go is an integral part of the development process. The Go programming language comes with a built-in testing framework that makes it easy to write and run tests.

Suppose you have a simple function that adds two numbers in a file named calculator.go:

// calculator.go

package calculator

// Add returns the sum of two integers
func Add(a, b int) int {
    return a + b
}

Now, create a test file named calculator_test.go in the same directory to test the Add function:

// calculator_test.go

package calculator

import "testing"

func TestAdd(t *testing.T) {
    result := Add(2, 3)
    expected := 5

    if result != expected {
        t.Errorf("Add(2, 3) = %d; expected %d", result, expected)
    }
}

Test functions must be in files ending with _test.go and have a name starting with Test.

To run the tests, use the go test command:

go test

Benchmarking

Benchmarking is a process of measuring the performance of functions or pieces of code.

// calculator.go

package calculator

// Factorial calculates the factorial of n
func Factorial(n int) int {
    if n <= 1 {
        return 1
    }
    return n * Factorial(n-1)
}

// calculator_benchmark_test.go

package calculator

import (
	"testing"
)

func BenchmarkFactorial(b *testing.B) {
	for i := 0; i < b.N; i++ {
		Factorial(10) // Replace 10 with the value you want to benchmark
	}
}

BenchmarkFactorial is the benchmark function. The b.N loop runs the code inside the loop repeatedly to measure its performance.

To run the benchmark, use the go test command with the -bench flag:

go test -bench .

Output will include the time taken for each iteration and the number of operations per second. Benchmark results can help you identify performance bottlenecks and optimize your code.