Fix #288 Add configuration option to omit dependency exclusions stanzas from flattened POM

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

@@ -252,6 +252,16 @@ public class FlattenMojo
     @Parameter( required = false )
     private FlattenDescriptor pomElements;
 
+    /**
+     * Dictates whether dependency exclusions stanzas should be included in the flattened POM. By default exclusions
+     * will be included in the flattened POM but if you wish to omit exclusions stanzas from being present then set
+     * this configuration property to <code>true</code>.
+     *
+     * @since 1.3.0
+     */
+    @Parameter( defaultValue = "false", required = false )
+    private boolean omitExclusions;
+
     /**
      * The different possible values for flattenMode:
      * <table border="1" summary="">
@@ -1014,7 +1024,12 @@ protected List<Dependency> createFlattenedDependencies( Model effectiveModel )
                             // Non build-time driven profiles will remain in the flattened POM with their dependencies
                             // and
                             // allow dynamic dependencies due to OS or JDK.
-                            flattenedDependencies.add( modelDependencies.resolve(profileDependency) );
+                            Dependency resolvedProfileDependency = modelDependencies.resolve(profileDependency);
+                            if ( omitExclusions )
+                            {
+                                resolvedProfileDependency.setExclusions(Collections.emptyList());
+                            }
+                            flattenedDependencies.add( resolvedProfileDependency );
                         }
                     }
                 }
@@ -1120,26 +1135,29 @@ private void createFlattenedDependenciesAll( List<Dependency> projectDependencie
             dependency.setScope(artifact.getScope());
             dependency.setType(artifact.getType());
 
-            List<Exclusion> exclusions = new LinkedList<>();
+            if ( !omitExclusions )
+            {
+                List<Exclusion> exclusions = new LinkedList<>();
 
-            org.eclipse.aether.artifact.Artifact aetherArtifact = new DefaultArtifact(artifact.getGroupId(), artifact.getArtifactId(), null, artifact.getVersion());
-            ArtifactDescriptorRequest request = new ArtifactDescriptorRequest(aetherArtifact, null, null);
-            ArtifactDescriptorResult artifactDescriptorResult = this.artifactDescriptorReader
+                org.eclipse.aether.artifact.Artifact aetherArtifact = new DefaultArtifact(artifact.getGroupId(), artifact.getArtifactId(), null, artifact.getVersion());
+                ArtifactDescriptorRequest request = new ArtifactDescriptorRequest(aetherArtifact, null, null);
+                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();
+                  exclusion.setGroupId(artifactDependency.getArtifact().getGroupId());
+                  exclusion.setArtifactId(artifactDependency.getArtifact().getArtifactId());
+                  exclusions.add(exclusion);
                 }
-                Exclusion exclusion = new Exclusion();
-                exclusion.setGroupId(artifactDependency.getArtifact().getGroupId());
-                exclusion.setArtifactId(artifactDependency.getArtifact().getArtifactId());
-                exclusions.add(exclusion);
-            }
 
-            dependency.setExclusions(exclusions);
+                dependency.setExclusions(exclusions);
+            }
 
             // convert dependency to string for the set, since Dependency doesn't implement equals, etc.
             String dependencyString = dependency.getManagementKey();
@@ -1190,7 +1208,17 @@ protected void createFlattenedDependencies( Model effectiveModel, List<Dependenc
      */
     protected Dependency createFlattenedDependency( Dependency projectDependency )
     {
-        return "test".equals( projectDependency.getScope() ) ? null : projectDependency;
+        if ( "test".equals( projectDependency.getScope() ) )
+        {
+            return null;
+        }
+
+        if ( omitExclusions )
+        {
+            projectDependency.setExclusions(Collections.emptyList());
+        }
+
+        return projectDependency;
     }
 
     /**

src/test/java/org/codehaus/mojo/flatten/FlattenMojoOmitExclusionsTest.java

@@ -0,0 +1,77 @@
+package org.codehaus.mojo.flatten;
+
+import static org.junit.Assert.fail;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+import org.apache.maven.model.Model;
+import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
+import org.apache.maven.plugin.testing.MojoRule;
+import org.apache.maven.project.MavenProject;
+import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
+import org.junit.After;
+import org.junit.Rule;
+import org.junit.Test;
+
+/**
+ * Test case for the omitexclusions configuration option.
+ */
+public class FlattenMojoOmitExclusionsTest {
+
+  private static final String PATH = "src/test/resources/omit-exclusions/";
+  private static final String FLATTENED_POM = PATH + ".flattened-pom.xml";
+
+  @Rule public MojoRule rule = new MojoRule();
+
+
+  /**
+   * Verify that when the omit exclusions configuration option is set then the
+   * exclusions stanza of any dependencies is not copied into the flattened
+   * POM.
+   */
+  @Test
+  public void testOmitExclusions() throws Exception {
+    // -- Given...
+    //
+    MavenProject project = rule.readMavenProject( new File( PATH ) );
+    FlattenMojo flattenMojo = (FlattenMojo) rule.lookupConfiguredMojo( project, "flatten" );
+
+    // -- When...
+    //
+    flattenMojo.execute();
+
+    // -- Then...
+    //
+    readPom( FLATTENED_POM )
+       .getDependencies()
+       .stream()
+       .filter(dep -> !dep.getExclusions().isEmpty())
+       .findAny()
+       .ifPresent(dep -> fail("No exclusions should be present in flattened POM."));
+  }
+
+
+  private static Model readPom(String pomFilePath) throws IOException, XmlPullParserException {
+    try ( FileInputStream input = new FileInputStream( new File( pomFilePath ) ) ) {
+      return new MavenXpp3Reader().read( input );
+    }
+  }
+
+
+  /**
+   * After test method. Removes flattened-pom.xml file which is created during test.
+   *
+   * @throws IOException if can't remove file.
+   */
+  @After
+  public void removeFlattenedPom() throws IOException {
+    File flattenedPom = new File( FLATTENED_POM );
+    if ( flattenedPom.exists() ) {
+      if ( !flattenedPom.delete() ) {
+        throw new IOException( "Can't delete " +  flattenedPom );
+      }
+    }
+  }
+}

src/test/resources/omit-exclusions/pom.xml

@@ -0,0 +1,36 @@
+<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>
+  <!-- https://github.com/mojohaus/flatten-maven-plugin/issues/288 -->
+  <artifactId>omit-exclusions</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <dependencies>
+    <dependency>
+      <groupId>groupA</groupId>
+      <artifactId>artifactB</artifactId>
+      <version>1</version>
+      <exclusions>
+        <exclusion>
+          <groupId>groupX</groupId>
+          <artifactId>artifactY</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>group1</groupId>
+          <artifactId>artifact2</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+  </dependencies>
+  <build>
+    <defaultGoal>verify</defaultGoal>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>flatten-maven-plugin</artifactId>
+        <configuration>
+          <omitExclusions>true</omitExclusions>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+</project>