IT: verify annotation processor in the same reactor can be used by a sibling module

core-it-suite/src/test/java/org/apache/maven/it/MavenITgh13911ReactorAnnotationProcessorTest.java

@@ -0,0 +1,63 @@
+/*
+ * 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.
+ */
+package org.apache.maven.it;
+
+import java.io.File;
+
+import org.apache.maven.shared.verifier.Verifier;
+import org.apache.maven.shared.verifier.util.ResourceExtractor;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Integration test for <a href="https://github.com/apache/maven/issues/13911">GH-13911</a>.
+ *
+ * <p>Verifies that an annotation processor (AP) built from source in the same Maven reactor
+ * can be used by a sibling module during its {@code compile} phase.  The POM {@code provided}
+ * dependency on the AP module gives Maven the ordering information it needs; no special
+ * reactor-plugin detection (MNG-1088 class) is required.</p>
+ */
+class MavenITgh13911ReactorAnnotationProcessorTest extends AbstractMavenIntegrationTestCase {
+
+    MavenITgh13911ReactorAnnotationProcessorTest() {
+        // Annotation processors via provided dep ordering works since Maven 3.0
+        super("[3.0,)");
+    }
+
+    /**
+     * Verify that Maven correctly orders the AP module before the client module and that the
+     * annotation processor generates its output file.
+     *
+     * @throws Exception in case of failure
+     */
+    @Test
+    void testReactorAnnotationProcessor() throws Exception {
+        File testDir = ResourceExtractor.simpleExtractResources(getClass(), "/gh-13911-reactor-ap");
+
+        Verifier verifier = newVerifier(testDir.getAbsolutePath());
+        verifier.setAutoclean(false);
+        verifier.deleteDirectory("client/target");
+        verifier.deleteArtifacts("org.apache.maven.its.gh13911");
+        verifier.addCliArgument("compile");
+        verifier.execute();
+        verifier.verifyErrorFreeLog();
+
+        // The annotation processor must have run and written its marker resource
+        verifier.verifyFilePresent("client/target/classes/META-INF/generated-by-gh13911.txt");
+    }
+}

core-it-suite/src/test/resources/gh-13911-reactor-ap/client/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+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.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.apache.maven.its.gh13911</groupId>
+    <artifactId>aggregator</artifactId>
+    <version>1.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>client</artifactId>
+  <packaging>jar</packaging>
+
+  <name>Maven Integration Test :: GH-13911 :: Client (uses reactor AP)</name>
+  <description>Uses the annotation processor built from source in the sibling module.
+    The provided dependency on the processor triggers Maven's reactor ordering.</description>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.maven.its.gh13911</groupId>
+      <artifactId>processor</artifactId>
+      <version>1.0-SNAPSHOT</version>
+      <scope>provided</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <configuration>
+          <!--
+            Explicit annotationProcessorPaths is the recommended modern approach.
+            The reactor-built processor artifact is resolved from target/classes via the
+            workspace reader (no install phase required), so the dependency ordering
+            created by the provided-scope dep above is sufficient.
+          -->
+          <annotationProcessorPaths>
+            <path>
+              <groupId>org.apache.maven.its.gh13911</groupId>
+              <artifactId>processor</artifactId>
+              <version>1.0-SNAPSHOT</version>
+            </path>
+          </annotationProcessorPaths>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>

core-it-suite/src/test/resources/gh-13911-reactor-ap/client/src/main/java/org/apache/maven/its/gh13911/ClientClass.java

@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+package org.apache.maven.its.gh13911;
+
+/**
+ * Client class annotated with the reactor-built annotation processor's annotation.
+ */
+@Gh13911Generated
+public class ClientClass {}

core-it-suite/src/test/resources/gh-13911-reactor-ap/pom.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+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.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.apache.maven.its.gh13911</groupId>
+  <artifactId>aggregator</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>pom</packaging>
+
+  <name>Maven Integration Test :: GH-13911 :: Reactor Annotation Processor</name>
+  <description>Verifies that an annotation processor built in the same Maven reactor can be used by a sibling
+    module during its compile phase.</description>
+
+  <modules>
+    <module>processor</module>
+    <module>client</module>
+  </modules>
+
+  <properties>
+    <maven.compiler.source>8</maven.compiler.source>
+    <maven.compiler.target>8</maven.compiler.target>
+  </properties>
+</project>

core-it-suite/src/test/resources/gh-13911-reactor-ap/processor/pom.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+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.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.apache.maven.its.gh13911</groupId>
+    <artifactId>aggregator</artifactId>
+    <version>1.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>processor</artifactId>
+  <packaging>jar</packaging>
+
+  <name>Maven Integration Test :: GH-13911 :: Annotation Processor</name>
+</project>

core-it-suite/src/test/resources/gh-13911-reactor-ap/processor/src/main/java/org/apache/maven/its/gh13911/Gh13911Generated.java

@@ -0,0 +1,31 @@
+/*
+ * 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.
+ */
+package org.apache.maven.its.gh13911;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marker annotation processed by {@link Gh13911Processor} at compile time.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.SOURCE)
+public @interface Gh13911Generated {}

core-it-suite/src/test/resources/gh-13911-reactor-ap/processor/src/main/java/org/apache/maven/its/gh13911/Gh13911Processor.java

@@ -0,0 +1,64 @@
+/*
+ * 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.
+ */
+package org.apache.maven.its.gh13911;
+
+import javax.annotation.processing.AbstractProcessor;
+import javax.annotation.processing.RoundEnvironment;
+import javax.annotation.processing.SupportedAnnotationTypes;
+import javax.annotation.processing.SupportedSourceVersion;
+import javax.lang.model.SourceVersion;
+import javax.lang.model.element.TypeElement;
+import javax.tools.Diagnostic;
+import javax.tools.FileObject;
+import javax.tools.StandardLocation;
+
+import java.io.IOException;
+import java.io.Writer;
+import java.util.Set;
+
+/**
+ * Annotation processor for the GH-13911 integration test.
+ * <p>
+ * When it finds any type annotated with {@link Gh13911Generated}, it writes a resource file
+ * {@code META-INF/generated-by-gh13911.txt} to the class output directory.
+ */
+@SupportedAnnotationTypes("org.apache.maven.its.gh13911.Gh13911Generated")
+@SupportedSourceVersion(SourceVersion.RELEASE_8)
+public class Gh13911Processor extends AbstractProcessor {
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+        if (annotations.isEmpty() || roundEnv.processingOver()) {
+            return false;
+        }
+        try {
+            FileObject resource = processingEnv
+                    .getFiler()
+                    .createResource(StandardLocation.CLASS_OUTPUT, "", "META-INF/generated-by-gh13911.txt");
+            try (Writer writer = resource.openWriter()) {
+                writer.write("[GH-13911] annotation processor ran successfully\n");
+            }
+        } catch (IOException e) {
+            processingEnv
+                    .getMessager()
+                    .printMessage(Diagnostic.Kind.ERROR, "[GH-13911] failed to write marker: " + e.getMessage());
+        }
+        return true;
+    }
+}

core-it-suite/src/test/resources/gh-13911-reactor-ap/processor/src/main/resources/META-INF/services/javax.annotation.processing.Processor

@@ -0,0 +1 @@
+org.apache.maven.its.gh13911.Gh13911Processor