Package org.apache.juneau.bct.junit

Annotation Interface TestBean

@Documented @Retention(RUNTIME) @Target({FIELD,METHOD}) public @interface TestBean
Marks a field or method on a JUnit 5 test class as a test-time bean override.

@TestBean is the Juneau analog of Spring's @MockBean / @TestConfiguration, scoped to a BeanStore overlay rather than a Spring application context. The JuneauBeanStoreExtension discovers @TestBean-annotated members on the test class, builds a TestBeanStore overlay containing the declared overrides, and exposes it via JuneauBeanStoreExtension.getStore() so the test author can wire it into the SUT explicitly (typically via a builder hook such as MockRestClient.Builder.overridingBeanStore(...)).

The wiring is intentionally explicit: the extension does not auto-discover RestContext / Microservice fields on the test class. Test authors write one line of plumbing (.overridingBeanStore(ext.getStore())) and get full control.

The annotation supports two wiring modes via mode(): Mode INJECT (default, fresh-instance with overrides via the SUT's builder) and Mode OVERLAY (existing-instance push/pop against a long-lived SUT's bean store). See JuneauBeanStoreExtension for the full Mode INJECT / Mode OVERLAY contracts.

Applies to:
  • Fields — the field's current value (read via reflection) is registered as the override.
  • Methods — a parameterless factory method whose return type is type-compatible with the override target. Invoked once per scope (per-method for Scope.METHOD, per-class for Scope.CLASS).
Example:

@ExtendWith(JuneauBeanStoreExtension.class) class MyResourceTest { @TestBean MyExternalApi mockApi = Mockito.mock(MyExternalApi.class); @TestBean(name="primary") static MyService primaryService() { return new InMemoryMyService("p"); } @Test void aTest(TestBeanStore store) { var client = MockRestClient.create(MyResource.class) .overridingBeanStore(store) .build(); client.get("/widgets/1").run().assertStatus().is(200); } }

See Also:
Since:
10.0.0

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    Mode
    mode
    Wiring mode for the override.
    String
    name
    Qualifier name for the override.
    Scope
    scope
    Lifecycle scope of the override.
    Class<?>
    type
    Explicit override target type.

  • Element Details

    • name

      String name
      Qualifier name for the override.

      Empty string (the default) means the override is registered as the unnamed bean of its type, matching the behavior of TestBeanStore.override(Class, Object) without a name argument.

      When non-empty, the override is registered under this qualifier so the framework's @Bean(name = "...") parameter resolution can find it. Two @TestBean-declared overrides of the same type but different names are both picked up — the qualifier is the disambiguator.

      Returns:
      The qualifier name. Empty string means "unnamed".
      Since:
      10.0.0
      Default:
      ""

    • type

      Class<?> type
      Explicit override target type.

      Object.class (the default) is a sentinel meaning "use the annotated member's declared type" — the field's declared type for field overrides, the method's return type for method overrides. This is the common case.

      Set this explicitly when the member's declared type is a supertype of the intended registration type, for example an Object field carrying a MyService value, or a @TestBean Supplier<MyService> factory method whose semantic type is MyService.

      Returns:
      The override target type. Object.class means "use the member's declared type".
      Since:
      10.0.0
      Default:
      java.lang.Object.class

    • scope

      Scope scope
      Lifecycle scope of the override.

      Defaults to Scope.METHOD — the override is rebuilt for every test method. Use Scope.CLASS to share the override across all test methods in the class.

      CLASS-scope overrides may only be declared on static fields and static methods. Instance members are not visible at beforeAll time and will be rejected with an error.

      Returns:
      The lifecycle scope.
      Since:
      10.0.0
      Default:
      METHOD

    • mode

      Mode mode
      Wiring mode for the override.

      Defaults to Mode.INJECT — the override is installed at SUT construction time via the SUT's overridingBeanStore(...) builder hook. Use Mode.OVERLAY for push/pop overlays against a long-lived SUT that the test has attach-ed to the extension.

      Mixing Mode.INJECT and Mode.OVERLAY annotations on the same scope is rejected at scope-build time with a clear IllegalStateException.

      Returns:
      The wiring mode.
      Since:
      10.0.0
      Default:
      INJECT