Allow to customize Plexus container by test class

pom.xml

@@ -9,7 +9,7 @@
   </parent>
 
   <artifactId>plexus-testing</artifactId>
-  <version>1.6.2-SNAPSHOT</version>
+  <version>1.7.0-SNAPSHOT</version>
 
   <name>Plexus Testing</name>
   <description>Library to help testing plexus components</description>
@@ -36,7 +36,7 @@
 
   <properties>
     <versions.eclipse.sisu>0.9.0.M4</versions.eclipse.sisu>
-    <project.build.outputTimestamp>2025-10-11T14:58:36Z</project.build.outputTimestamp>
+    <project.build.outputTimestamp>2025-10-13T21:13:09Z</project.build.outputTimestamp>
   </properties>
 
   <dependencies>
@@ -72,6 +72,19 @@
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-api</artifactId>
     </dependency>
+
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <version>4.11.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-junit-jupiter</artifactId>
+      <version>4.11.0</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

src/main/java/org/codehaus/plexus/testing/PlexusExtension.java

@@ -58,7 +58,7 @@
  * This is a slightly modified version of the original plexus class
  * available at https://raw.githubusercontent.com/codehaus-plexus/plexus-containers/master/plexus-container-default/
  *              src/main/java/org/codehaus/plexus/PlexusTestCase.java
- * in order to migrate the tests to JUnit 4.
+ * in order to migrate the tests to JUnit 5.
  *
  * @author Jason van Zyl
  * @author <a href="mailto:[email protected]">Trygve Laugst&oslash;l</a>
@@ -94,7 +94,6 @@ protected void setContext(ExtensionContext context) {
         this.context = context;
     }
 
-    @SuppressWarnings("ResultOfMethodCallIgnored")
     protected void setupContainer() {
         // ----------------------------------------------------------------------------
         // Context Setup
@@ -136,12 +135,14 @@ protected void setupContainer() {
         }
 
         customizeContainerConfiguration(containerConfiguration);
+        testInstanceCustomizeContainerConfiguration(containerConfiguration);
 
         try {
             container = new DefaultPlexusContainer(containerConfiguration);
         } catch (PlexusContainerException e) {
             throw new IllegalArgumentException("Failed to create plexus container.", e);
         }
+        testInstanceCustomizeContainer(container);
     }
 
     /**
@@ -155,6 +156,20 @@ protected void customizeContainerConfiguration(ContainerConfiguration containerC
         containerConfiguration.setClassPathScanning(PlexusConstants.SCANNING_INDEX);
     }
 
+    private void testInstanceCustomizeContainerConfiguration(ContainerConfiguration containerConfiguration) {
+        Object testInstance = context.getRequiredTestInstance();
+        if (testInstance instanceof PlexusTestConfiguration) {
+            ((PlexusTestConfiguration) testInstance).customizeConfiguration(containerConfiguration);
+        }
+    }
+
+    private void testInstanceCustomizeContainer(PlexusContainer container) {
+        Object testInstance = context.getRequiredTestInstance();
+        if (testInstance instanceof PlexusTestConfiguration) {
+            ((PlexusTestConfiguration) testInstance).customizeContainer(container);
+        }
+    }
+
     protected void customizeContext(Context context) {}
 
     protected PlexusConfiguration customizeComponentConfiguration() {

src/main/java/org/codehaus/plexus/testing/PlexusTestConfiguration.java

@@ -0,0 +1,28 @@
+package org.codehaus.plexus.testing;
+
+import org.codehaus.plexus.ContainerConfiguration;
+import org.codehaus.plexus.PlexusContainer;
+
+/**
+ * Allow to customize the Plexus container by test class.
+ *
+ * @since 1.7.0
+ */
+public interface PlexusTestConfiguration {
+
+    /**
+     * Customize the container configuration before the container is created.
+     *
+     * @param containerConfiguration the container configuration to customize
+     * @since 1.7.0
+     */
+    default void customizeConfiguration(ContainerConfiguration containerConfiguration) {}
+
+    /**
+     * Customize the container after it has been created.
+     *
+     * @param container the container to customize
+     * @since 1.7.0
+     */
+    default void customizeContainer(PlexusContainer container) {}
+}

src/site/markdown/index.md

@@ -8,6 +8,14 @@ Library to help testing plexus components
 
 <!-- MACRO{snippet|id=test-class|file=src/test/java/org/codehaus/plexus/testing/PlexusTestJavaxTest.java} -->
 
+### Customization of the Plexus Container
+
+Test class can customize the Plexus Container used for testing by implementing
+the [`PlexusTestConfiguration`](apidocs/org/codehaus/plexus/testing/PlexusTestConfiguration.html).
+All methods have default empty implementations so you can implement only the ones you need.
+
+<!-- MACRO{snippet|id=test-customize-class|file=src/test/java/org/codehaus/plexus/testing/PlexusTestCustomizeTest.java} -->
+
 ### Used classes in test
 
 <!-- MACRO{snippet|id=test-component|file=src/test/java/org/codehaus/plexus/testing/TestJavaxComponent.java} -->

src/test/java/org/codehaus/plexus/testing/PlexusTestCustomizeTest.java

@@ -0,0 +1,66 @@
+package org.codehaus.plexus.testing;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+// START SNIPPET: test-customize-class
+import javax.inject.Inject;
+
+import org.codehaus.plexus.PlexusContainer;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+
+// MockitoExtension must be first
+@ExtendWith(MockitoExtension.class)
+@PlexusTest
+class PlexusTestCustomizeTest implements PlexusTestConfiguration {
+
+    @Mock
+    private TestJavaxComponent2 mockComponent2;
+
+    /*
+    Customize the container configuration before it is used to create the container.
+
+    Method has default empty implementation so not need to implement if not used.
+
+    @Override
+    public void customizeConfiguration(ContainerConfiguration containerConfiguration) {
+
+    }
+    */
+
+    @Override
+    public void customizeContainer(PlexusContainer container) {
+        container.addComponent(mockComponent2, TestJavaxComponent2.class.getName());
+    }
+
+    @Inject
+    private TestJavaxComponent testJavaxComponent;
+
+    @Test
+    void dependencyShouldBeInjected() {
+        assertNotNull(testJavaxComponent);
+        assertSame(testJavaxComponent.getTestComponent2(), mockComponent2);
+    }
+}
+// END SNIPPET: test-customize-class