Revert to a simplified extension model

documentation/src/docs/asciidoc/extensions.adoc

@@ -11,8 +11,7 @@ JUnit 4, the JUnit 5 extension model consists of a single, coherent concept: the
 [[extension-registration]]
 === Registering Extensions
 
-Extensions can be registered either declaratively via `{ExtendWith}` or programmatically
-via an `{ExtensionRegistrar}`.
+Extensions can be registered declaratively via `{ExtendWith}`.
 
 Note that registered extensions are inherited within test class hierarchies.
 
@@ -60,85 +59,6 @@ class MyTestsV2 {
 The execution of tests in both `MyTestsV1` and `MyTestsV2` will be extended by the
 `FooExtension` and `BarExtension`, in exactly that order.
 
-[[extension-registration-programmatic]]
-==== Programmatic Extension Registration
-
-Developers can register one or more extensions _programmatically_ by implementing the
-`{ExtensionRegistrar}` API and registering the custom `ExtensionRegistrar` implementation
-via `@ExtendWith` as mentioned above. The following examples demonstrate the various
-options in implementations of the `ExtensionRegistrar.registerExtensions()` method.
-
-===== 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 using the _default_ `Position`.
-
-[source,java,indent=0]
-[subs="verbatim"]
-----
-public void registerExtensions(ExtensionPointRegistry registry) {
-    CustomExtension customExtension = // instantiate extension
-    registry.register(customExtension);
-}
-----
-
-If you would like to influence the order in which multiple implementations of the same
-`ExtensionPoint` API are applied, you can do so by registering the extensions
-programmatically and supplying the `Position`. The following values are permitted.
-
-- `OUTERMOST`: Applied first. Only a single extension is allowed to be assigned this
-  position; otherwise, an `ExtensionConfigurationException` will be thrown.
-- `OUTSIDE_DEFAULT`: Applied after `OUTERMOST` but before `DEFAULT`, `INSIDE_DEFAULT`,
-  and `INNERMOST`. Multiple extensions can be assigned this position; however, the
-  ordering among such extensions is undefined.
-- `DEFAULT`: (?)
-- `INSIDE_DEFAULT`: (?)
-- `INNERMOST`: (?)
-
-The following listing demonstrates how to configure an explicit position for an instance
-of an extension. Note, however, that a `Position` can also be supplied for lambda
-expressions and method references.
-
-[source,java,indent=0]
-[subs="verbatim"]
-----
-public void registerExtensions(ExtensionPointRegistry registry) {
-    registry.register(new TimingExtension(), 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_.
-
-[source,java,indent=0]
-[subs="verbatim"]
-----
-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_.
-
-[source,java,indent=0]
-[subs="verbatim"]
-----
-public void registerExtensions(ExtensionPointRegistry registry) {
-    registry.register((BeforeEachExtensionPoint) this::beforeEach);
-}
-
-void beforeEach(TestExtensionContext context) {
-    /* ... */
-}
-----
-
 
 === Conditional Test Execution
 
@@ -165,6 +85,7 @@ initialization methods on the test instance, etc.
 For concrete examples, consult the source code for the `{MockitoExtension}` and the
 `{SpringExtension}`.
 
+
 === Parameter Resolution
 
 `{MethodParameterResolver}` is an `Extension` strategy for dynamically resolving
@@ -178,25 +99,29 @@ resolved by _name_, _type_, _annotation_, or any combination thereof. For concre
 consult the source code for `{CustomTypeParameterResolver}` and
 `{CustomAnnotationParameterResolver}`.
 
+
 === Test Lifecycle Callbacks
 
 The following interfaces define the APIs for extending tests at various points in the
 test execution lifecycle. Consult the Javadoc for each of these in the
-`{extension-api-package}` package.
+`{extension-api-package}` package for further details.
 
-* `BeforeEachExtensionPoint`
-* `AfterEachExtensionPoint`
-* `BeforeAllExtensionPoint`
-* `AfterAllExtensionPoint`
+* `BeforeAllCallback`
+* `AfterAllCallback`
+* `BeforeEachCallback`
+* `AfterEachCallback`
+* `BeforeTestMethodCallback`
+* `AfterTestMethodCallback`
 
 Note that extension developers may choose to implement any number of these interfaces
 within a single extension. Consult the source code of the `{SpringExtension}` for a
 concrete example.
 
+
 === Exception Handling
 
-`{ExceptionHandlerExtensionPoint}` defines the API for `Extensions` that wish to _react to
-exceptions_ thrown in a test.
+`{ExceptionHandler}` defines the API for `Extensions` that wish to handle exceptions
+thrown from tests.
 
 The following example shows an extension which will swallow all instances of `IOException`
 but rethrow any other type of exception:
@@ -209,14 +134,12 @@ include::{testDir}/example/exception/IgnoreIOExceptionExtension.java[tags=user_g
 ----
 
 
-
 === Keeping State in Extensions
 
 Usually, an extension is instantiated only once. So the question becomes relevant: How do you keep the state
 from one invocation of an extension point to the next? ...
 
 
-
 === Additional Planned Extensions
 
 Several additional extensions are planned, including but not limited to the following:

documentation/src/docs/asciidoc/index.adoc

@@ -28,7 +28,7 @@ Stefan Bechtold; Sam Brannen; Johannes Link; Matthias Merdes; Marc Philipp
 :CustomTypeParameterResolver:       {master-branch}/junit-tests/src/test/java/org/junit/gen5/engine/junit5/execution/injection/sample/CustomTypeParameterResolver.java[CustomTypeParameterResolver]
 :Disabled:                          {master-branch}/junit5-api/src/main/java/org/junit/gen5/api/Disabled.java[@Disabled]
 :DisabledCondition:                 {master-branch}/junit5-engine/src/main/java/org/junit/gen5/engine/junit5/extension/DisabledCondition.java[DisabledCondition]
-:ExceptionHandlerExtensionPoint:    {master-branch}/junit5-api/src/main/java/org/junit/gen5/api/extension/ExceptionHandlerExtensionPoint.java[ExceptionHandlerExtensionPoint]
+:ExceptionHandler:                  {master-branch}/junit5-api/src/main/java/org/junit/gen5/api/extension/ExceptionHandler.java[ExceptionHandler]
 :ExtendWith:                        {master-branch}/junit5-api/src/main/java/org/junit/gen5/api/extension/ExtendWith.java[@ExtendWith]
 :ExtensionRegistrar:                {master-branch}/junit5-api/src/main/java/org/junit/gen5/api/extension/ExtensionRegistrar.java[ExtensionRegistrar]
 :InstancePostProcessor:             {master-branch}/junit5-api/src/main/java/org/junit/gen5/api/extension/InstancePostProcessor.java[InstancePostProcessor]

documentation/src/test/java/example/exception/IgnoreIOExceptionExtension.java

@@ -12,12 +12,12 @@
 
 import java.io.IOException;
 
-import org.junit.gen5.api.extension.ExceptionHandlerExtensionPoint;
+import org.junit.gen5.api.extension.ExceptionHandler;
 import org.junit.gen5.api.extension.TestExtensionContext;
 
 // @formatter:off
 // tag::user_guide[]
-public class IgnoreIOExceptionExtension implements ExceptionHandlerExtensionPoint {
+public class IgnoreIOExceptionExtension implements ExceptionHandler {
 
 	@Override
 	public void handleException(TestExtensionContext context, Throwable throwable)

documentation/src/test/java/example/timing/TimingExtension.java

@@ -10,17 +10,13 @@
 
 package example.timing;
 
-import static org.junit.gen5.api.extension.ExtensionPointRegistry.Position.INNERMOST;
-
 import java.lang.reflect.Method;
 import java.util.logging.Logger;
 
-import org.junit.gen5.api.extension.AfterEachExtensionPoint;
-import org.junit.gen5.api.extension.BeforeEachExtensionPoint;
-import org.junit.gen5.api.extension.ExtensionContext;
+import org.junit.gen5.api.extension.AfterTestMethodCallback;
+import org.junit.gen5.api.extension.BeforeTestMethodCallback;
 import org.junit.gen5.api.extension.ExtensionContext.Namespace;
-import org.junit.gen5.api.extension.ExtensionPointRegistry;
-import org.junit.gen5.api.extension.ExtensionRegistrar;
+import org.junit.gen5.api.extension.ExtensionContext.Store;
 import org.junit.gen5.api.extension.TestExtensionContext;
 
 /**
@@ -29,37 +25,26 @@
  *
  * @since 5.0
  */
-public class TimingExtension implements ExtensionRegistrar {
+public class TimingExtension implements BeforeTestMethodCallback, AfterTestMethodCallback {
 
 	private static final Logger LOG = Logger.getLogger(TimingExtension.class.getName());
 
 	@Override
-	public void registerExtensions(ExtensionPointRegistry registry) {
-		registry.register(new TestMethodInvocationWrapper(), INNERMOST);
+	public void beforeTestMethod(TestExtensionContext context) throws Exception {
+		getStore(context).put(context.getTestMethod(), System.currentTimeMillis());
 	}
 
-	private static class TestMethodInvocationWrapper implements BeforeEachExtensionPoint, AfterEachExtensionPoint {
-
-		@Override
-		public void beforeEach(TestExtensionContext context) throws Exception {
-			ExtensionContext.Store times = context.getStore(getNamespace(context));
-			times.put(context.getTestMethod(), System.currentTimeMillis());
-		}
-
-		private Namespace getNamespace(TestExtensionContext context) {
-			return Namespace.of(getClass(), context);
-		}
-
-		@Override
-		public void afterEach(TestExtensionContext context) throws Exception {
-			ExtensionContext.Store times = context.getStore(getNamespace(context));
-			Method testMethod = context.getTestMethod();
-			long start = (long) times.remove(testMethod);
-			long duration = System.currentTimeMillis() - start;
+	@Override
+	public void afterTestMethod(TestExtensionContext context) throws Exception {
+		Method testMethod = context.getTestMethod();
+		long start = (long) getStore(context).remove(testMethod);
+		long duration = System.currentTimeMillis() - start;
 
-			LOG.info(() -> String.format("Method [%s] took %s ms.", testMethod, duration));
-		}
+		LOG.info(() -> String.format("Method [%s] took %s ms.", testMethod, duration));
+	}
 
+	private Store getStore(TestExtensionContext context) {
+		return context.getStore(Namespace.of(getClass(), context));
 	}
 
 }

documentation/src/test/java/extensions/ExpectToFailExtension.java

@@ -12,13 +12,13 @@
 
 import static org.junit.gen5.api.Assertions.assertNotNull;
 
-import org.junit.gen5.api.extension.AfterEachExtensionPoint;
-import org.junit.gen5.api.extension.ExceptionHandlerExtensionPoint;
+import org.junit.gen5.api.extension.AfterEachCallback;
+import org.junit.gen5.api.extension.ExceptionHandler;
 import org.junit.gen5.api.extension.ExtensionContext.Namespace;
 import org.junit.gen5.api.extension.ExtensionContext.Store;
 import org.junit.gen5.api.extension.TestExtensionContext;
 
-public class ExpectToFailExtension implements ExceptionHandlerExtensionPoint, AfterEachExtensionPoint {
+public class ExpectToFailExtension implements ExceptionHandler, AfterEachCallback {
 
 	@Override
 	public void handleException(TestExtensionContext context, Throwable throwable) throws Throwable {

junit-tests/src/test/java/org/junit/gen5/console/tasks/TempDirectory.java

@@ -23,15 +23,15 @@
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 
-import org.junit.gen5.api.extension.AfterEachExtensionPoint;
+import org.junit.gen5.api.extension.AfterEachCallback;
 import org.junit.gen5.api.extension.ExtensionContext;
 import org.junit.gen5.api.extension.ExtensionContext.Namespace;
 import org.junit.gen5.api.extension.MethodInvocationContext;
 import org.junit.gen5.api.extension.MethodParameterResolver;
 import org.junit.gen5.api.extension.ParameterResolutionException;
 import org.junit.gen5.api.extension.TestExtensionContext;
 
-public class TempDirectory implements AfterEachExtensionPoint, MethodParameterResolver {
+public class TempDirectory implements AfterEachCallback, MethodParameterResolver {
 
 	@Target(ElementType.PARAMETER)
 	@Retention(RetentionPolicy.RUNTIME)