Module org.junit.jupiter.params
Package org.junit.jupiter.params

Annotation Interface BeforeParameterizedClassInvocation

@Target({ANNOTATION_TYPE,METHOD}) @Retention(RUNTIME) @Documented @API(status=EXPERIMENTAL, since="5.13") public @interface BeforeParameterizedClassInvocation
@BeforeParameterizedClassInvocation is used to signal that the annotated method should be executed before each invocation of the current @ParameterizedClass.

Declaring @BeforeParameterizedClassInvocation methods in a regular, non-parameterized test class has no effect and will be ignored.

Method Signatures

@BeforeParameterizedClassInvocation methods must have a void return type, must not be private, and must be static by default. Consequently, @BeforeParameterizedClassInvocation methods are not supported in @Nested test classes or as interface default methods unless the test class is annotated with @TestInstance(Lifecycle.PER_CLASS). However, beginning with Java 16 @BeforeParameterizedClassInvocation methods may be declared as static in @Nested test classes, in which case the Lifecycle.PER_CLASS restriction no longer applies.

Method Arguments

@BeforeParameterizedClassInvocation methods may optionally declare parameters that are resolved depending on the setting of the injectArguments() attribute.

If injectArguments() is set to false, the parameters must be resolved by other registered ParameterResolvers.

If injectArguments() is set to true (the default), the method must declare the same parameters, in the same order, as the indexed parameters (see @ParameterizedClass) of the parameterized test class. It may declare a subset of the indexed parameters starting from the first argument. Additionally, the method may declare custom aggregator parameters (see @ParameterizedClass) at the end of its parameter list. If the method declares additional parameters after these aggregator parameters, or more parameters than the class has indexed parameters, they may be resolved by other ParameterResolvers.

For example, given a @ParameterizedClass with indexed parameters of type int and String, the following method signatures are valid: 


 @BeforeParameterizedClassInvocation
 void beforeInvocation() { ... }

 @BeforeParameterizedClassInvocation
 void beforeInvocation(int number) { ... }

 @BeforeParameterizedClassInvocation
 void beforeInvocation(int number, String text) { ... }

 @BeforeParameterizedClassInvocation
 void beforeInvocation(int number, String text, TestInfo testInfo) { ... }

 @BeforeParameterizedClassInvocation
 void beforeInvocation(ArgumentsAccessor accessor) { ... }

 @BeforeParameterizedClassInvocation
 void beforeInvocation(ArgumentsAccessor accessor, TestInfo testInfo) { ... }

 @BeforeParameterizedClassInvocation
 void beforeInvocation(int number, String text, ArgumentsAccessor accessor) { ... }

 @BeforeParameterizedClassInvocation
 void beforeInvocation(int number, String text, ArgumentsAccessor accessor, TestInfo testInfo) { ... }

In the snippet above,ArgumentsAccessor is used as an example of an aggregator parameter but the same applies to any parameter annotated with @AggregateWith. The parameter of type TestInfo is used as an example of a parameter that is resolved by another ParameterResolver.

Inheritance and Execution Order

@BeforeParameterizedClassInvocation methods are inherited from superclasses as long as they are not overridden according to the visibility rules of the Java language. Furthermore, @BeforeParameterizedClassInvocation methods from superclasses will be executed before @BeforeParameterizedClassInvocation methods in subclasses.

Similarly, @BeforeParameterizedClassInvocation methods declared in an interface are inherited as long as they are not overridden, and @BeforeParameterizedClassInvocation methods from an interface will be executed before @BeforeParameterizedClassInvocation methods in the class that implements the interface.

JUnit Jupiter does not guarantee the execution order of multiple @BeforeParameterizedClassInvocation methods that are declared within a single parameterized test class or test interface. While it may at times appear that these methods are invoked in alphabetical order, they are in fact sorted using an algorithm that is deterministic but intentionally non-obvious.

In addition, @BeforeParameterizedClassInvocation methods are in no way linked to @AfterParameterizedClassInvocation methods. Consequently, there are no guarantees with regard to their wrapping behavior. For example, given two @BeforeParameterizedClassInvocation methods createA() and createB() as well as two @AfterParameterizedClassInvocation methods destroyA() and destroyB(), the order in which the @BeforeParameterizedClassInvocation methods are executed (e.g. createA() before createB()) does not imply any order for the seemingly corresponding @AfterParameterizedClassInvocation methods. In other words, destroyA() might be called before or after destroyB(). The JUnit Team therefore recommends that developers declare at most one @BeforeParameterizedClassInvocation method and at most one @AfterParameterizedClassInvocation method per test class or test interface unless there are no dependencies between the @BeforeParameterizedClassInvocation methods or between the @AfterParameterizedClassInvocation methods.

Composition

@BeforeParameterizedClassInvocation may be used as a meta-annotation in order to create a custom composed annotation that inherits the semantics of @BeforeParameterizedClassInvocation.

Since:
5.13
See Also:

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    boolean
    injectArguments
    Whether the arguments of the parameterized test class should be injected into the annotated method (defaults to false).

  • Element Details

    • injectArguments

      boolean injectArguments
      Whether the arguments of the parameterized test class should be injected into the annotated method (defaults to false).
      Default:
      true