How to Use Testify for Assertions and Mocking in Go

Use the assert package for non-fatal checks and the mock package to simulate dependencies by embedding mock.Mock in your test structs.

package yours

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
)

// MyMockedObject embeds mock.Mock to enable mocking
type MyMockedObject struct {
	mock.Mock
}

// DoSomething implements the interface method
func (m *MyMockedObject) DoSomething(number int) (bool, error) {
	args := m.Called(number)
	return args.Bool(0), args.Error(1)
}

func TestSomething(t *testing.T) {
	// Setup mock
	testObj := new(MyMockedObject)
	testObj.On("DoSomething", 123).Return(true, nil)

	// Execute code using testObj
	// targetFuncThatDoesSomethingWithObj(testObj)

	// Assert expectations were met
	testObj.AssertExpectations(t)

	// Use assert for value checks
	assert.Equal(t, true, true, "values should be equal")
}

Testify helps you write better Go tests by providing easy ways to check if your code works as expected. You use assertions to verify results without stopping the test, and mocks to pretend external services or databases exist so you can test your logic in isolation. Think of it as a safety net that catches bugs and a fake environment that lets you test without needing real dependencies.