Unit Test

Why do we need testing?

Improve the quality of your product
Enhancing the development process
Saving your time and your money

Different Types of Tests

Test-driven Development

Test your code!

math_test.go

package math

import "testing"

func TestAdd(t *testing.T) {
	result := Add(1, 3)

	if result != 4 {
		t.Errorf("Add(1, 3) FAILED. Expected %d, got %d\n", 4, result)
	} else {
		t.Logf("Add(1, 3) PASSED. Expected %d, got %d\n", 4, result)
	}
}

Run the Test

❯ go test
PASS
ok      go-unit-test/math       0.001s
❯ go test -v
=== RUN   TestAdd
    math_test.go:11: Add(1, 3) PASSED. Expected 4, got 4
--- PASS: TestAdd (0.00s)
PASS
ok      go-unit-test/math       0.001s
❯ go test --cover
PASS
coverage: 25.0% of statements
ok      go-unit-test/math       0.001s

Failure Case

func TestDivide(t *testing.T) {
	result := Divide(1, 2)

	if result != 0.5 {
		t.Errorf("Divide(1, 2) FAILED. Expected %f, got %f\n", 0.5, result)
	} else {
		t.Logf("Divide(1, 2) PASSED. Expected %f, got %f\n", 0.5, result)
	}
}

Run the Failure Test

❯ go test -v
=== RUN   TestAdd
    math_test.go:11: Add(1, 3) PASSED. Expected 4, got 4
--- PASS: TestAdd (0.00s)
=== RUN   TestDivide
    math_test.go:19: Divide(1, 2) FAILED. Expected 0.500000, got 0.000000
--- FAIL: TestDivide (0.00s)
FAIL
exit status 1
FAIL    go-unit-test/math       0.001s

The AAA Pattern

Arrange
Act
Assert

Install assert

❯ go get github.com/stretchr/testify/assert

import (
	"testing"
	"github.com/stretchr/testify/assert"
)

Try it!

func TestSub(t *testing.T) {
	// Arrange
	var a int = 13
	var b int = 9
	var expected int = 4
	// Act
	var actual int = Subtract(a, b)
	// Assert
	assert.EqualValues(t, expected, actual, "Expected %d, got %f\n", expected, actual)
}

Result

❯ go test -v --cover
=== RUN   TestAdd
    math_test.go:15: Add(1, 3) PASSED. Expected 4, got 4
--- PASS: TestAdd (0.00s)
=== RUN   TestDivide
    math_test.go:23: Divide(1, 2) FAILED. Expected 0.500000, got 0.000000
--- FAIL: TestDivide (0.00s)
=== RUN   TestSub
--- PASS: TestSub (0.00s)
FAIL
coverage: 75.0% of statements
exit status 1
FAIL    go-unit-test/math       0.002s

Ginkgo

 var _ = Describe("Books", func() {
  var book *books.Book
  BeforeEach(func() {
    book = &books.Book{
      Title: "Les Miserables",
      Author: "Victor Hugo",
      Pages: 2783,
    }
    Expect(book.IsValid()).To(BeTrue())
  })
  It("can extract the author's last name", func() {
    Expect(book.AuthorLastName()).To(Equal("Hugo"))
  })
})

Unit Test in Go

Why do we need testing?

Different Types of Tests

Test-driven Development

Unit Test

Creating a Test

Structure

math.go

math_test.go

Run the Test

Failure Case

Run the Failure Test

The AAA Pattern

Install assert

Try it!

Result

Ginkgo

Reference

	var _ = Describe("Books", func() {
	var book *books.Book
	BeforeEach(func() {
	book = &books.Book{
	Title: "Les Miserables",
	Author: "Victor Hugo",
	Pages: 2783,
	}
	Expect(book.IsValid()).To(BeTrue())
	})
	It("can extract the author's last name", func() {
	Expect(book.AuthorLastName()).To(Equal("Hugo"))
	})
	})