org.junit.gen5.api.extension

Interface ExtensionPointRegistry

@API(value=Experimental)
public interface ExtensionPointRegistry

A registry for ExtensionPoint implementations which can be populated via an ExtensionRegistrar.

Example Usage

All examples below are implementations of ExtensionRegistrar.registerExtensions(org.junit.gen5.api.extension.ExtensionPointRegistry).

Registering an ExtensionPoint Instance

If you have an instance of an extension that implements one or more ExtensionPoint APIs, you can register it as follows.

 public void registerExtensions(ExtensionPointRegistry registry) {
     CustomExtension customExtension = // instantiate extension
     registry.register(customExtension);
 }
 

Similarly, an instance of an extension can be registered with an explicit ExtensionPointRegistry.Position as follows.

 public void registerExtensions(ExtensionPointRegistry registry) {
     CustomExtension customExtension = // instantiate extension
     registry.register(customExtension, Position.INNERMOST);
 }
 

Registering a Lambda Expression as an ExtensionPoint

If you would like to implement a single ExtensionPoint API as a lambda expression, you can register it as follows. Note, however, that the API must be a functional interface.

 public void registerExtensions(ExtensionPointRegistry registry) {
     registry.register((BeforeEachExtensionPoint) context -> { /* ... */ });
 }
 

Registering a Method Reference as an ExtensionPoint

If you would like to implement a single ExtensionPoint API via a method reference, you can register it as follows. Note, however, that the API must be a functional interface.

 public void registerExtensions(ExtensionPointRegistry registry) {
     registry.register((BeforeEachExtensionPoint) this::beforeEach);
 }

 void beforeEach(TestExtensionContext context) {
     /* ... */
 }
 

Since:

5.0

See Also:

ExtensionPoint, ExtensionRegistrar

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ExtensionPointRegistry.Position Position specifies the position in which a registered ExtensionPoint is applied with regard to all other registered extension points of the same type.

Method Summary

Modifier and Type	Method and Description
default void	register(ExtensionPoint extensionPoint) Register the supplied ExtensionPoint using the default position.
void	register(ExtensionPoint extensionPoint, ExtensionPointRegistry.Position position) Register the supplied ExtensionPoint using the supplied ExtensionPointRegistry.Position.

Method Detail

register

default void register(ExtensionPoint extensionPoint)

Register the supplied ExtensionPoint using the default position.

See the class-level Javadoc and user guide for examples.

Parameters:

extensionPoint - the extension point to register

See Also:

register(ExtensionPoint, Position)

register

void register(ExtensionPoint extensionPoint,
              ExtensionPointRegistry.Position position)

Register the supplied ExtensionPoint using the supplied ExtensionPointRegistry.Position.

See the class-level Javadoc and user guide for examples.

Parameters:

extensionPoint - the extension point to register

position - the position in which the extension point should be registered

See Also:

register(ExtensionPoint)