Comparison of golang mocking libraries

golang-mocks.md

Comparison of golang mocking libraries

Updated 2022-12-22

	gomock	testify + mockery	minimock	moq
Library
GitHub stars		+
Latest release date		+
Maintained	✅	✅	✅	✅
Mock creation
Code generation 1	✅	✅	✅	✅
Not only code generation 2	❌	✅	❌	❌
Use t.Cleanup() 3	✅	✅	❌	❌
Support generics	❌	✅	❌	✅
DSL
Execute custom func 4	✅	✅	✅	✅
Typed expected arguments 5	✖️	✖️	✔️	✔️
Typed returned values 6	✖️	✔️	✔️	✔️
Calls order 7	✅	✅	❌	❌
Wait for time.Duration 8	❌	✅	❌	❌
Wait for message from chan 9	❌	✅	❌	❌
Panic 10	❌	✅	❌	❌
Assert expectations with timeout	❌	❌	✅	❌
Return zero values by default 11	✅	❌	❌	❌
Calls count
Exact calls count 12	✅	✅	❌	❌
Min/max calls count 13	✅	❌	❌	❌
Any positive calls count	✅	❌	✅	❌
Any calls count	✅	✅	❌	❌
Expect once by default 14	✅	❌	❌	❌
Matchers
Any value	✅	✅	❌	❌
Equal to	✅	✅	❌	❌
Not equal to	✅	❌	❌	❌
Is nil	✅	❌	❌	❌
Type is	✅	✅	❌	❌
Length is	✅	❌	❌	❌
Slice elements in any order	✅	❌	❌	❌
Custom matcher	✅	✅	❌	❌

Examples

gomock

func TestGomock(t *testing.T) {
	ctrl := gomock.NewController(t)
	m := NewMockMyInterface(ctrl)
	gomock.InOrder(
		m.EXPECT().Method(gomock.Any(), "abc").Return(123, nil),
		m.EXPECT().AnotherMethod(gomock.Any(), gomock.Len(3)),
	)
	...
}

testify/mock + mockery

func TestTestifyMock(t *testing.T) {
	m := mocks.NewMyInterface(t)
	m.EXPECT().Method(mock.Anything, "abc").After(5*time.Second).Return(123, nil).Once()
	m.EXPECT().AnotherMethod(mock.Anything, "abc").Return(0, nil).Once()
	...
}

minimock

func TestMinimock(t *testing.T) {
	ctrl := minimock.NewController(t)
	t.Cleanup(ctrl.Finish)
	m := NewMyInterfaceMock(ctrl)
	m.MethodMock.When(context.Background(), "abc").Then(123, nil)
	m.AnotherMethodMock.When(context.Background(), "abc").Then(0, nil)
	...
}

moq

func TestMoq(t *testing.T) {
	m := MyInterfaceMock{
		MethodFunc: func(ctx context.Context, s string) (int, error) {
			assert.Equal(t, "abc", s)
			return 123, nil
		},
		AnotherMethodFunc: func(ctx context.Context, s string) (int, error) {
			assert.Len(t, s, 1)
			return 0, nil
		},
	}
	t.Cleanup(func() {
		assert.Len(t, m.MethodCalls(), 1)
		assert.Len(t, m.AnotherMethodCalls(), 1)
	})
	...
}

Footnotes

1. CLI tool to auto generate mocks from interfaces ↩

2. Allow writing mock manually, without code generation ↩

3. Mock constructor uses t.Cleanup() to assert expectations after test by default ↩

4. Use arbitrary function to execute, allowing to implement any feature in the table ↩

5. Defining expected arguments in test doesn't rely on empty interface{} ↩

6. Defining returned values in test doesn't rely on empty interface{} ↩

7. Define expected order of calls ↩

8. Block execution of method using time.Sleep() ↩

9. Block execution of method using <- channel ↩

10. Panic instead of method execution ↩

11. Not defining return values leads to returning zero values ↩

12. Define expected exact number of calls in test ↩

13. Define expected min/max number of calls in test ↩

14. Not defining number of calls leads to expectation that method to be called once ↩