Add more goals to help plugin (self documenting any Maven version)

src/main/java/org/apache/maven/plugins/help/ListDependencyTypesMojo.java

@@ -0,0 +1,101 @@
+/*
+ * 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.plugins.help;
+
+import javax.inject.Inject;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.TreeMap;
+
+import org.apache.maven.artifact.handler.ArtifactHandler;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
+import org.apache.maven.plugins.annotations.Mojo;
+import org.apache.maven.project.ProjectBuilder;
+import org.eclipse.aether.RepositorySystem;
+
+/**
+ * Displays a list of artifact handlers that are defined in Maven.
+ *
+ * @since 3.5.2
+ */
+@Mojo(name = "list-dependency-types", requiresProject = false, aggregator = true)
+public class ListDependencyTypesMojo extends AbstractHelpMojo {
+    /**
+     * The Maven default built-in lifecycles.
+     */
+    private final Map<String, ArtifactHandler> artifactHandlers;
+
+    @Inject
+    public ListDependencyTypesMojo(
+            ProjectBuilder projectBuilder,
+            RepositorySystem repositorySystem,
+            Map<String, ArtifactHandler> artifactHandlers) {
+        super(projectBuilder, repositorySystem);
+        this.artifactHandlers = artifactHandlers;
+    }
+
+    // ----------------------------------------------------------------------
+    // Mojo parameters
+    // ----------------------------------------------------------------------
+
+    // ----------------------------------------------------------------------
+    // Public methods
+    // ----------------------------------------------------------------------
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void execute() throws MojoExecutionException, MojoFailureException {
+        try {
+            StringBuilder descriptionBuffer = new StringBuilder();
+            for (Map.Entry<String, ArtifactHandler> handlerEntry : new TreeMap<>(artifactHandlers).entrySet()) {
+                if ("default".equals(handlerEntry.getKey())) {
+                    continue;
+                }
+                descriptionBuffer.append(handlerEntry.getKey()).append(LS);
+                ArtifactHandler handler = handlerEntry.getValue();
+                descriptionBuffer
+                        .append(" - Extension: ")
+                        .append("*.")
+                        .append(handler.getExtension())
+                        .append(LS);
+                if (handler.getClassifier() != null && !handler.getClassifier().isEmpty()) {
+                    descriptionBuffer
+                            .append(" - Classifier: ")
+                            .append(handler.getClassifier())
+                            .append(LS);
+                }
+                if (handler.isAddedToClasspath()) {
+                    descriptionBuffer.append(" - Added to Classpath").append(LS);
+                }
+                if (handler.isIncludesDependencies()) {
+                    descriptionBuffer.append(" - Includes dependencies").append(LS);
+                }
+                descriptionBuffer.append(LS);
+            }
+            getLog().info(LS + "Maven Dependency Types defined:" + LS + LS + descriptionBuffer);
+            writeFile(output, descriptionBuffer);
+        } catch (IOException e) {
+            throw new MojoFailureException(e);
+        }
+    }
+}

src/main/java/org/apache/maven/plugins/help/ListLifecyclePhasesMojo.java

@@ -0,0 +1,82 @@
+/*
+ * 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.plugins.help;
+
+import javax.inject.Inject;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.maven.lifecycle.DefaultLifecycles;
+import org.apache.maven.lifecycle.Lifecycle;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
+import org.apache.maven.plugins.annotations.Mojo;
+import org.apache.maven.project.ProjectBuilder;
+import org.eclipse.aether.RepositorySystem;
+
+/**
+ * Displays a list of lifecycle phases that are defined in Maven.
+ *
+ * @since 3.5.2
+ */
+@Mojo(name = "list-lifecycle-phases", requiresProject = false, aggregator = true)
+public class ListLifecyclePhasesMojo extends AbstractHelpMojo {
+    /**
+     * The Maven default built-in lifecycles.
+     */
+    private final DefaultLifecycles defaultLifecycles;
+
+    @Inject
+    public ListLifecyclePhasesMojo(
+            ProjectBuilder projectBuilder, RepositorySystem repositorySystem, DefaultLifecycles defaultLifecycles) {
+        super(projectBuilder, repositorySystem);
+        this.defaultLifecycles = defaultLifecycles;
+    }
+
+    // ----------------------------------------------------------------------
+    // Mojo parameters
+    // ----------------------------------------------------------------------
+
+    // ----------------------------------------------------------------------
+    // Public methods
+    // ----------------------------------------------------------------------
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void execute() throws MojoExecutionException, MojoFailureException {
+        try {
+            StringBuilder descriptionBuffer = new StringBuilder();
+            List<Lifecycle> lifecycles = defaultLifecycles.getLifeCycles();
+            for (Lifecycle lifecycle : lifecycles) {
+                descriptionBuffer.append(lifecycle.getId()).append(LS);
+                lifecycle
+                        .getPhases()
+                        .forEach(p -> descriptionBuffer.append(" * ").append(p).append(LS));
+                descriptionBuffer.append(LS);
+            }
+            getLog().info(LS + "Maven lifecycles defined:" + LS + LS + descriptionBuffer);
+            writeFile(output, descriptionBuffer);
+        } catch (IOException e) {
+            throw new MojoFailureException(e);
+        }
+    }
+}

src/main/java/org/apache/maven/plugins/help/ListPackagingMojo.java

@@ -0,0 +1,123 @@
+/*
+ * 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.plugins.help;
+
+import javax.inject.Inject;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.Objects;
+import java.util.TreeMap;
+
+import org.apache.maven.lifecycle.DefaultLifecycles;
+import org.apache.maven.lifecycle.mapping.Lifecycle;
+import org.apache.maven.lifecycle.mapping.LifecycleMapping;
+import org.apache.maven.lifecycle.mapping.LifecycleMojo;
+import org.apache.maven.lifecycle.mapping.LifecyclePhase;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.MojoFailureException;
+import org.apache.maven.plugins.annotations.Mojo;
+import org.apache.maven.project.ProjectBuilder;
+import org.eclipse.aether.RepositorySystem;
+
+/**
+ * Displays a list of packaging that are defined in Maven.
+ *
+ * @since 3.5.2
+ */
+@Mojo(name = "list-packaging", requiresProject = false, aggregator = true)
+public class ListPackagingMojo extends AbstractHelpMojo {
+    /**
+     * The Maven default built-in lifecycles.
+     */
+    private final DefaultLifecycles defaultLifecycles;
+
+    /**
+     * The Maven default built-in lifecycles.
+     */
+    private final Map<String, LifecycleMapping> lifecycleMapping;
+
+    @Inject
+    public ListPackagingMojo(
+            ProjectBuilder projectBuilder,
+            RepositorySystem repositorySystem,
+            DefaultLifecycles defaultLifecycles,
+            Map<String, LifecycleMapping> lifecycleMapping) {
+        super(projectBuilder, repositorySystem);
+        this.defaultLifecycles = defaultLifecycles;
+        this.lifecycleMapping = lifecycleMapping;
+    }
+
+    // ----------------------------------------------------------------------
+    // Mojo parameters
+    // ----------------------------------------------------------------------
+
+    // ----------------------------------------------------------------------
+    // Public methods
+    // ----------------------------------------------------------------------
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void execute() throws MojoExecutionException, MojoFailureException {
+        try {
+            StringBuilder descriptionBuffer = new StringBuilder();
+            for (Map.Entry<String, LifecycleMapping> lifecycleMappingEntry :
+                    new TreeMap<>(lifecycleMapping).entrySet()) {
+                LifecycleMapping lifecycleMapping = lifecycleMappingEntry.getValue();
+                for (Map.Entry<String, Lifecycle> phaseEntry :
+                        lifecycleMapping.getLifecycles().entrySet()) {
+                    Lifecycle mapping = phaseEntry.getValue();
+                    descriptionBuffer
+                            .append(lifecycleMappingEntry.getKey())
+                            .append(" (lifecycle: ")
+                            .append(mapping.getId())
+                            .append(")")
+                            .append(LS);
+                    org.apache.maven.lifecycle.Lifecycle lifecycle = getLifecycle(mapping.getId());
+                    for (String phase : lifecycle.getPhases()) {
+                        LifecyclePhase lphase = mapping.getLifecyclePhases().get(phase);
+                        if (lphase != null) {
+                            descriptionBuffer.append("  - ").append(phase).append(LS);
+                            for (LifecycleMojo mojo : lphase.getMojos()) {
+                                descriptionBuffer
+                                        .append("    - ")
+                                        .append(mojo.getGoal())
+                                        .append(LS);
+                            }
+                        }
+                    }
+                }
+                descriptionBuffer.append(LS);
+            }
+            getLog().info(LS + "Maven packaging defined:" + LS + LS + descriptionBuffer);
+            writeFile(output, descriptionBuffer);
+        } catch (IOException e) {
+            throw new MojoFailureException(e);
+        }
+    }
+
+    private org.apache.maven.lifecycle.Lifecycle getLifecycle(String name) {
+        return defaultLifecycles.getLifeCycles().stream()
+                .filter(l -> Objects.equals(name, l.getId()))
+                .findFirst()
+                .orElseThrow(() -> new IllegalArgumentException("No such lifecycle"));
+    }
+}