Mocking static methods (Mockito 3.4+) in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start mocking static methods using Mockito.

JUnit

try (MockedStatic<Utility> utilities = Mockito.[1](Utility.class)) {
    // test code
}

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

AmockStatic

BwhenStatic

CstaticMock

DmockStaticMethod

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'whenStatic' instead of 'mockStatic'.

Trying to mock static methods without using try-with-resources.

Use Mockito.mockStatic(Class.class) to create a mock for static methods of a class.

2fill in blank

medium

Complete the code to stub a static method to return a specific value.

JUnit

utilities.[1](() -> Utility.staticMethod()).thenReturn("mocked value");

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AdoReturn

Bwhen

Cstub

Dmock

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'doReturn' which is for instance methods.

Trying to stub without a lambda expression.

Use 'when' to specify the static method call to stub and then define the return value.

3fill in blank

hard

Fix the error in the code to verify a static method was called once.

JUnit

utilities.verify(() -> Utility.staticMethod(), [1]);

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Aonce()

BcalledOnce()

Ctimes(1)

DverifyOnce()

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like 'calledOnce' or 'once'.

Omitting the verification mode argument.

Use 'times(1)' to verify the static method was called exactly once.

4fill in blank

hard

Fill both blanks to mock two different static methods with different return values.

JUnit

utilities.[1](() -> Utility.firstStatic()).thenReturn(10);
utilities.[2](() -> Utility.secondStatic()).thenReturn(20);

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Awhen

BdoReturn

Cstub

Dmock

Attempts:

3 left

💡 Hint

Common Mistakes

Using different stubbing methods inconsistently.

Trying to stub without lambda expressions.

Use 'when' to stub each static method call with the desired return value.

5fill in blank

hard

Fill all three blanks to correctly open, stub, and close the static mock.

JUnit

try (MockedStatic<Utility> utilities = Mockito.[1](Utility.class)) {
    utilities.[2](() -> Utility.staticMethod()).thenReturn("done");
} // [3] closes the mock automatically

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

AmockStatic

Bwhen

Ctry-with-resources

Dclose

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to use try-with-resources to close the mock.

Using incorrect methods to open or stub the mock.

Use 'mockStatic' to open the mock, 'when' to stub the method, and 'try-with-resources' ensures automatic closing.