org.mockito.junit

Interface MockitoRule

All Superinterfaces:

MethodRule

public interface MockitoRule
extends MethodRule

Since 2.1.0, JUnit rule emits stubbing warnings and hints to System output (see also MockitoHint). The JUnit rule can be used instead of MockitoJUnitRunner. It requires JUnit at least 4.7. This rule adds following behavior:

• Since 2.1.0, stubbing warnings and hints are printed to System output. Hints contain clickable links that take you right to the line of code that contains a possible problem. Please give us feedback about the stubbing warnings of JUnit rules in the issue tracker (issue 384). It's a new feature of Mockito 2.1.0. It aims to help debugging tests. If you wish the previous behavior, see silent(). However, we would really like to know why do you wish to silence the warnings! See also MockitoHint.
• Initializes mocks annotated with Mock, so that explicit usage of MockitoAnnotations.initMocks(Object) is not necessary. Mocks are initialized before each test method.
• Validates framework usage after each test method. See javadoc for Mockito.validateMockitoUsage().

Example use:

 public class ExampleTest {

     @Rule
     public MockitoRule rule = MockitoJUnit.rule();

     @Mock
     private List list;

     @Test
     public void shouldDoSomething() {
         list.add(100);
     }
 }
 

Since:

1.10.17

Method Summary

Methods

Modifier and Type	Method and Description
MockitoRule	silent() Rule will not report stubbing warnings during test execution.
MockitoRule	strictness(Strictness strictness) The strictness, especially "strict stubs" (Strictness.STRICT_STUBS) can really make a difference when debugging and keeping tests clean.

Methods inherited from interface org.junit.rules.MethodRule

apply

Method Detail

silent

MockitoRule silent()

Rule will not report stubbing warnings during test execution. By default, stubbing warnings are printed to Standard output to help debugging. Equivalent of configuring strictness(Strictness) with Strictness.LENIENT.

Please give us feedback about the stubbing warnings of JUnit rules by commenting on GitHub issue 769. It's a new feature of Mockito 2.1.0. It aims to help debugging tests. We want to make sure the feature is useful. We would really like to know why do you wish to silence the warnings! See also MockitoHint.

Example:

 public class ExampleTest {

     @Rule
     public MockitoRule rule = MockitoJUnit.rule().silent();

 }
 

Since:

2.1.0

strictness

@Incubating
MockitoRule strictness(Strictness strictness)

The strictness, especially "strict stubs" (Strictness.STRICT_STUBS) can really make a difference when debugging and keeping tests clean. It's a new feature introduced in Mockito 2.3. Other levels of strictness - "Warn" - current default (Strictness.WARN) and "lenient" (silent()) strictness was already present in Mockito 2.1.0. Version 2.3.0 introduces "strict stubs" (Strictness.STRICT_STUBS).

 public class ExampleTest {
     @Rule
     public MockitoRule rule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
 }
 

How strictness level influences the behavior of JUnit rule:

1. Strictness.LENIENT - equivalent of silent() - no added behavior. The default of Mockito 1.x
2. Strictness.WARN - helps keeping tests clean and with debuggability. Reports console warnings about unused stubs and stubbing argument mismatch (see MockitoHint). The default of Mockito 2.x
3. Strictness.STRICT_STUBS - ensures clean tests, reduces test code duplication, improves debuggability. Adds following behavior:
   • Improved debuggability: the test fails early when code under test invokes stubbed method with different arguments (see PotentialStubbingProblem).
   • Cleaner tests without unnecessary stubbings: the test fails when there are any unused stubs declared (see UnnecessaryStubbingException).
   • Cleaner, more DRY tests ("Don't Repeat Yourself"): If you use Mockito.verifyNoMoreInteractions(Object...) you no longer need to explicitly verify stubbed invocations. They are automatically verified.

"Strict stubs" are tentatively planned to be the default for Mockito 3.x

We are very eager to hear feedback about "strict stubbing" feature, let us know by commenting on GitHub issue 769. Strict stubbing is an attempt to improve testability and productivity with Mocktio. Tell us what you think!

Since:

2.3.0