verify() for interaction verification in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to verify that the method save() was called exactly once on the mock object.

JUnit

verify(mockObject).[1]();

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

Aexecute

Bstart

Crun

Dsave

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name that was never called on the mock.

Forgetting to call the method inside verify().

The verify() method checks that save() was called on the mock object. Only option D matches the method name to verify.

2fill in blank

medium

Complete the code to verify that the method delete() was never called on the mock object.

JUnit

verify(mockObject, [1]()).delete();

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

Anever

BatMost

Ctimes

DatLeastOnce

Attempts:

3 left

💡 Hint

Common Mistakes

Using times(0) instead of never() (both work but never() is clearer).

Using atLeastOnce() which means the method was called at least once.

Using never() verifies that the method was not called at all. This matches the requirement.

3fill in blank

hard

Fix the error in the code to verify that update() was called exactly twice on the mock object.

JUnit

verify(mockObject, [1](2)).update();

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

AatLeast

Bnever

Ctimes

DatMost

Attempts:

3 left

💡 Hint

Common Mistakes

Using never() which means zero calls.

Using atLeast(2) which means two or more calls.

The times(2) mode verifies the method was called exactly two times.

4fill in blank

hard

Fill both blanks to verify that the method process() was called at least once but no more than three times on the mock object.

JUnit

verify(mockObject, [1](1)).process();
verify(mockObject, [2](3)).process();

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

AatLeast

Btimes

CatMost

Dnever

Attempts:

3 left

💡 Hint

Common Mistakes

Using times() for range checks instead of atLeast and atMost.

Using never() which means zero calls.

Use atLeast(1) to check minimum calls and atMost(3) to check maximum calls.

5fill in blank

hard

Fill all three blanks to demonstrate verifications that the method calculate() was called exactly once, never called, and at least twice.

JUnit

verify(mockObject, [1](1)).calculate();
verify(mockObject, [2]()).calculate();
verify(mockObject, [3](2)).calculate();

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

Atimes

Bnever

CatLeast

DatMost

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up atMost and atLeast.

Using times() without a number.

First verify exactly once with times(1), verify never called with never(), and finally verify at least twice with atLeast(2).