MockK for mocking in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is MockK in Android Kotlin testing?

MockK is a Kotlin library used to create mock objects for unit testing. It helps simulate behavior of real objects to test code in isolation.

beginner

How do you create a mock object with MockK?

Use the function mockk<ClassName>() to create a mock instance of a class.

intermediate

What does the every { ... } returns ... syntax do in MockK?

It defines the behavior of a mocked function call. When the function inside every { } is called, it returns the specified value.

intermediate

How do you verify that a mocked function was called in MockK?

Use the verify { mock.functionName() } block to check if the function was called during the test.

advanced

What is the difference between mockk() and spyk() in MockK?

mockk() creates a pure mock with no real behavior, while spyk() creates a spy that wraps a real object and can call real methods unless mocked.

Which function creates a mock object in MockK?

A mockk()

B spy()

C stub()

D fake()

The mockk() function creates a mock object in MockK.

How do you specify the return value of a mocked function in MockK?

A when(function()).thenReturn(value)

B mock(function()).returns(value)

C given(function()).willReturn(value)

D every { function() } returns value

In MockK, use every { function() } returns value to specify return values.

What does the verify { ... } block do in MockK?

A Mocks a function

B Checks if a mocked function was called

C Creates a spy object

D Resets mocks

The verify { ... } block checks if a mocked function was called during the test.

Which MockK function creates a spy that calls real methods unless mocked?

A stubk()

B mockk()

C spyk()

D fakek()

spyk() creates a spy that wraps a real object and calls real methods unless mocked.

What is the main purpose of using MockK in Android testing?

A To simulate object behavior for unit tests

B To handle database queries

C To manage app navigation

D To create UI layouts

MockK is used to simulate object behavior to isolate and test code in unit tests.

Explain how to create and use a mock object with MockK in a Kotlin unit test.

Think about how you tell the mock what to do and how to check it was used.

Describe the difference between a mock and a spy in MockK and when you might use each.

Consider if you want to fake everything or keep some real behavior.