Overview

The ParameterizedTestParameterResolver conflicts with parameter resolution in @BeforeEach methods in the class containing the @ParameterizedTest. I would presume that parameterized @BeforeEach methods in super-classes as well as @AfterEach methods will have the same problem.

Bug report

• JUnit 5 version M4
• Current behavior: The ParameterizedTestParameterResolver attempts to provide parameter resolution for other methods. My opinion is that the ParameterResolver should make sure it's "injecting" parameters only for methods annotated with @ParameterizedTest.
• Expected behavior: The parameters provided on a @ParameterizedTest method would only resolve parameters on the annotated test method.

Example

In a class annotated with @ExtendWith(MockitoExtension.class), the following set-up and test methods are present:

  @BeforeEach
  void setUp(@Mock Consul.Builder consulBuilder, @Mock Consul consulClient) {
    doReturn(consulClient).when(consulBuilder).build();
    
    consulKeyInjector = new ConsulKeyInjector();
    consulKeyInjector.consulBuilder = consulBuilder;
    consulKeyInjector.consulClient = consulClient;
  }

  @ParameterizedTest
  @CsvSource({
      "CamelCase, CAMELCASE",
      "dotted.java.property, DOTTED_JAVA_PROPERTY",
      "ALREADY_AN_ENVIRONMENT_VARIABLE, ALREADY_AN_ENVIRONMENT_VARIABLE"
  })
  void testToEnvironmentName(String input, String expected) {
    String actual = ConsulKeyInjector.toEnvironmentName(input);
    assertThat(actual).isEqualTo(expected);
  }

Note that in this case, other @Test methods in this class are actually using the mocks. When this class' tests are executed, the following failure is logged:

testToEnvironmentName(String, String)  Time elapsed: 0.001 sec  <<< FAILURE!
org.junit.jupiter.api.extension.ParameterResolutionException: Discovered multiple competing ParameterResolvers for parameter [com.orbitz.consul.Consul$Builder arg0] in executable [void edu.psu.swe.consul.ConsulKeyInjectorTests.setUp(com.orbitz.consul.Consul$Builder,com.orbitz.consul.Consul)]: edu.psu.swe.consul.MockitoExtension, org.junit.jupiter.params.ParameterizedTestParameterResolver

Work-around

Allow the MockitoExtension's TestInstancePostProcessor to inject the mocks into member fields in the test class as shown below:

  @Mock
  Consul.Builder consulBuilder;
  
  @Mock
  Consul consulClient;
  
  ConsulKeyInjector consulKeyInjector;
  
  @BeforeEach
  void setUp() {
    doReturn(consulClient).when(consulBuilder).build();
    
    consulKeyInjector = new ConsulKeyInjector();
    consulKeyInjector.consulBuilder = consulBuilder;
    consulKeyInjector.consulClient = consulClient;
  }

Deliverables

• Limit the ParameterizedTestParameterResolver's scope to only the method it's annotating.