Mocking with MockK in Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a mock of the Calculator class using MockK.

Kotlin

val calculator = [1]<Calculator>()

Drag options to blanks, or click blank then click option'

Amock

Bmockk

Cspyk

Dfakek

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'spyk' instead of 'mockk' creates a spy, not a mock.

Using 'mock' or 'fakek' are not valid MockK functions.

Use mockk to create a mock object in MockK.

2fill in blank

medium

Complete the code to stub the add method to return 10 when called with any two integers.

Kotlin

every { calculator.add([1], [1]) } returns 10

Drag options to blanks, or click blank then click option'

AanyNumber()

BanyInt()

CanyValue()

Dany()

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'anyInt()' is not a valid MockK matcher.

Using 'anyValue()' or 'anyNumber()' do not exist in MockK.

Use any() to match any argument in MockK stubbing.

3fill in blank

hard

Fix the error in verifying that the subtract method was called exactly once with arguments 5 and 3.

Kotlin

verify(exactly = [1]) { calculator.subtract(5, 3) }

Drag options to blanks, or click blank then click option'

A1

B2

C0

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 means the method was never called.

Using 2 means verifying two calls, which is incorrect here.

Use exactly = 1 to verify the method was called once.

4fill in blank

hard

Fill both blanks to create a spy of the Service class and stub its fetchData method to return "data".

Kotlin

val service = [1]<Service>()
every { service.[2]() } returns "data"

Drag options to blanks, or click blank then click option'

Aspyk

Bmockk

CfetchData

DgetData

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'mockk' creates a mock, not a spy.

Using 'getData' is not the correct method name.

Use spyk to create a spy and stub the fetchData method.

5fill in blank

hard

Fill all three blanks to verify that the save method was called at least twice with any string argument.

Kotlin

verify(atLeast = [1]) { repository.[2]([3]) }

Drag options to blanks, or click blank then click option'

A1

Bsave

Cany()

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'atLeast = 1' checks for at least one call, not two.

Using wrong method name or argument matcher causes verification failure.

Use atLeast = 2 to check minimum calls, method name save, and any() to match any argument.