fixes #160: when the direct dependency is optional, flattened its tra…

…nsitive dependencies and set them as optional (#164)

* fixes #160: when the direct dependency is optional, flattened its transitive dependencies and set them as optional

* remove optional dependency subtree

* return false in visitor when node is not included

src/it/projects/flatten-dependency-all-depmgnt-optional/parent/pom.xml

@@ -0,0 +1,23 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.codehaus.mojo.flatten.its</groupId>
+  <artifactId>flatten-dependency-all-depmgnt-optional-parent</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <packaging>pom</packaging>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>org.codehaus.mojo.flatten.its</groupId>
+        <artifactId>core</artifactId>
+        <version>3.2.1</version>
+      </dependency>
+      <dependency>
+        <groupId>org.codehaus.mojo.flatten.its</groupId>
+        <artifactId>dep</artifactId>
+        <version>1.1</version>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
+</project>

src/it/projects/flatten-dependency-all-depmgnt-optional/pom.xml

@@ -0,0 +1,33 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.codehaus.mojo.flatten.its</groupId>
+  <artifactId>flatten-dependency-all-depmgnt-optional</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <parent>
+    <groupId>org.codehaus.mojo.flatten.its</groupId>
+    <artifactId>flatten-dependency-all-depmgnt-optional-parent</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <relativePath>parent</relativePath>
+  </parent>
+
+  <build>
+    <defaultGoal>verify</defaultGoal>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>flatten-maven-plugin</artifactId>
+        <configuration>
+          <flattenDependencyMode>all</flattenDependencyMode>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.codehaus.mojo.flatten.its</groupId>
+      <artifactId>core</artifactId>
+      <optional>true</optional>
+    </dependency>
+  </dependencies>
+</project>

src/it/projects/flatten-dependency-all-depmgnt-optional/verify.groovy

@@ -0,0 +1,32 @@
+/*
+ * 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.
+ */
+File originalPom = new File( basedir, 'pom.xml' )
+assert originalPom.exists()
+
+def originalProject = new XmlSlurper().parse( originalPom )
+assert 1 ==  originalProject.dependencies.size()
+assert "core" ==  originalProject.dependencies.dependency.artifactId.text()
+assert "true" ==  originalProject.dependencies.dependency.optional.text()
+
+File flattenedPom = new File( basedir, '.flattened-pom.xml' )
+assert flattenedPom.exists()
+
+def flattenedProject = new XmlSlurper().parse( flattenedPom )
+assert 0 ==  flattenedProject.dependencies.dependency.size()
+

src/it/projects/flatten-dependency-all-optional/pom.xml

@@ -0,0 +1,28 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>org.codehaus.mojo.flatten.its</groupId>
+  <artifactId>flatten-dependency-all-optional</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+
+  <build>
+    <defaultGoal>verify</defaultGoal>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>flatten-maven-plugin</artifactId>
+        <configuration>
+          <flattenDependencyMode>all</flattenDependencyMode>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.codehaus.mojo.flatten.its</groupId>
+      <artifactId>core</artifactId>
+      <version>3.2.1</version>
+      <optional>true</optional>
+    </dependency>
+  </dependencies>
+</project>

src/it/projects/flatten-dependency-all-optional/verify.groovy

@@ -0,0 +1,32 @@
+/*
+ * 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.
+ */
+File originalPom = new File( basedir, 'pom.xml' )
+assert originalPom.exists()
+
+def originalProject = new XmlSlurper().parse( originalPom )
+assert 1 ==  originalProject.dependencies.size()
+assert "core" ==  originalProject.dependencies.dependency.artifactId.text()
+assert "3.2.1" ==  originalProject.dependencies.dependency.version.text()
+assert "true" ==  originalProject.dependencies.dependency.optional.text()
+
+File flattenedPom = new File( basedir, '.flattened-pom.xml' )
+assert flattenedPom.exists()
+
+def flattenedProject = new XmlSlurper().parse( flattenedPom )
+assert 0 ==  flattenedProject.dependencies.dependency.size()

src/main/java/org/codehaus/mojo/flatten/FlattenMojo.java

@@ -1049,31 +1049,42 @@ private void createFlattenedDependenciesDirect( List<Dependency> projectDependen
      * @throws ArtifactDescriptorException
      */
     private void createFlattenedDependenciesAll( List<Dependency> projectDependencies, List<Dependency> flattenedDependencies )
-            throws DependencyTreeBuilderException, ArtifactDescriptorException {
-        final Queue<DependencyNode> dependencyNodeLinkedList = new LinkedList<DependencyNode>() {};
+            throws DependencyTreeBuilderException, ArtifactDescriptorException
+    {
+        final Queue<DependencyNode> dependencyNodeLinkedList = new LinkedList<DependencyNode>();
         final Set<String> processedDependencies = new HashSet<>();
 
         final Artifact projectArtifact = this.project.getArtifact();
 
         final DependencyNode dependencyNode = this.dependencyTreeBuilder.buildDependencyTree(this.project,
                 this.localRepository, null);
 
-        dependencyNode.accept(new DependencyNodeVisitor() {
-            @Override public boolean visit(DependencyNode node) {
-                if (node.getArtifact().getGroupId().equals(projectArtifact.getGroupId()) && node.getArtifact().getArtifactId().equals(projectArtifact.getArtifactId())) {
+        dependencyNode.accept(new DependencyNodeVisitor()
+        {
+            @Override public boolean visit(DependencyNode node)
+            {
+                if (node.getArtifact().getGroupId().equals(projectArtifact.getGroupId()) && node.getArtifact().getArtifactId().equals(projectArtifact.getArtifactId()))
+                {
                     return true;
                 }
-                if (node.getState() != DependencyNode.INCLUDED) return true;
+                if (node.getState() != DependencyNode.INCLUDED) {
+                    return false;
+                }
+                if (node.getArtifact().isOptional()) {
+                    return false;
+                }
                 dependencyNodeLinkedList.add(node);
                 return true;
             }
 
-            @Override public boolean endVisit(DependencyNode node) {
+            @Override public boolean endVisit(DependencyNode node)
+            {
                 return true;
             }
         });
 
-        while (!dependencyNodeLinkedList.isEmpty()) {
+        while (!dependencyNodeLinkedList.isEmpty())
+        {
             DependencyNode node = dependencyNodeLinkedList.poll();
 
             Artifact artifact = node.getArtifact();
@@ -1094,8 +1105,10 @@ private void createFlattenedDependenciesAll( List<Dependency> projectDependencie
             ArtifactDescriptorResult artifactDescriptorResult = this.artifactDescriptorReader
                     .readArtifactDescriptor(this.session.getRepositorySession(), request);
 
-            for (org.eclipse.aether.graph.Dependency artifactDependency: artifactDescriptorResult.getDependencies()) {
-                if ("test".equals(artifactDependency.getScope())) {
+            for (org.eclipse.aether.graph.Dependency artifactDependency: artifactDescriptorResult.getDependencies())
+            {
+                if ("test".equals(artifactDependency.getScope()))
+                {
                     continue;
                 }
                 Exclusion exclusion = new Exclusion();
@@ -1109,12 +1122,14 @@ private void createFlattenedDependenciesAll( List<Dependency> projectDependencie
             // convert dependency to string for the set, since Dependency doesn't implement equals, etc.
             String dependencyString = dependency.getManagementKey();
 
-            if (!processedDependencies.add(dependencyString)) {
+            if (!processedDependencies.add(dependencyString))
+            {
                 continue;
             }
 
             Dependency flattenedDependency = createFlattenedDependency( dependency );
-            if (flattenedDependency != null) {
+            if (flattenedDependency != null)
+            {
                 flattenedDependencies.add(flattenedDependency);
             }
         }