Render project .vm overrides with Velocity when useProjectFiles is set (#267)

src/main/java/org/apache/maven/plugin/resources/remote/AbstractProcessRemoteResourcesMojo.java

@@ -651,7 +651,7 @@
                     }
                 } else {
                     getLog().debug("Use project resource '" + source + "' as resource");
                     FilteringUtils.copyFile(source, outputFile, null, null);
                 }
 
                 // exclude the original (so eclipse doesn't complain about duplicate resources)
@@ -663,15 +663,34 @@
         return false;
     }
 
-    private boolean copyProjectRootIfExists(File outputFile, String bundleResourceName) throws IOException {
+    private boolean copyProjectRootIfExists(
+            File outputFile, String bundleResourceName, VelocityContext context, String encoding)
+            throws IOException, MojoExecutionException {
         if (!useProjectFiles) {
             return false;
         }
 
         File source = new File(project.getBasedir(), bundleResourceName);
+        File templateSource = new File(project.getBasedir(), bundleResourceName + TEMPLATE_SUFFIX);
+
+        if (!source.exists() && templateSource.exists()) {
+            source = templateSource;
+        }
+
         if (source.exists()) {
-            getLog().debug("Use project file '" + source + "' as resource");
-            FilteringUtils.copyFile(source, outputFile, null, null);
+            if (source == templateSource) {
+                getLog().debug("Use project file '" + source + "' as resource with Velocity");
+                try (CachingOutputStream os = new CachingOutputStream(outputFile);
+                        Writer writer = getWriter(encoding, os);
+                        Reader reader = getReader(encoding, source)) {
+                    velocity.evaluate(context, writer, "", reader);
+                } catch (ParseErrorException | MethodInvocationException | ResourceNotFoundException e) {
+                    throw new MojoExecutionException("Error rendering velocity resource: " + source, e);
+                }
+            } else {
+                getLog().debug("Use project file '" + source + "' as resource");
+                FilteringUtils.copyFile(source, outputFile, null, null);
+            }
             return true;
         }
 
@@ -942,7 +961,7 @@
                     continue;
                 }
 
-                if (copyProjectRootIfExists(outputFile, projectResource)) {
+                if (copyProjectRootIfExists(outputFile, projectResource, context, bundle.getSourceEncoding())) {
                     continue;
                 }
 

src/test/java/org/apache/maven/plugin/resources/remote/RemoteResourcesMojoTest.java

@@ -43,7 +43,7 @@
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.plugin.resources.remote.stub.MavenProjectBuildStub;
 import org.apache.maven.plugin.resources.remote.stub.MavenProjectResourcesStub;
 import org.apache.maven.plugin.testing.AbstractMojoTestCase;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.repository.internal.MavenRepositorySystemUtils;
 import org.codehaus.plexus.util.FileUtils;
@@ -58,7 +58,7 @@
 /**
  * RemoteResources plugin Test Case
  */
 public class RemoteResourcesMojoTest extends AbstractMojoTestCase {
     static final String DEFAULT_BUNDLE_POM_PATH = "target/test-classes/unit/rrmojotest/bundle-plugin-config.xml";
     static final String DEFAULT_PROCESS_POM_PATH = "target/test-classes/unit/rrmojotest/process-plugin-config.xml";
 
@@ -165,6 +165,31 @@
         assertTrue(file.exists());
     }
 
+    public void testUseProjectFilesRendersVelocityTemplate() throws Exception {
+        final MavenProjectResourcesStub project = createTestProject("default-useprojectfiles");
+        final ProcessRemoteResourcesMojo mojo = lookupProcessMojoWithSettings(project, new String[] {"test:test:1.4"});
+
+        setupDefaultProject(project);
+
+        FileUtils.fileWrite(
+                new File(project.getBasedir(), "FILTER.txt.vm").getAbsolutePath(), "local override: $project.name");
+
+        String path = pathOf(new DefaultArtifact(
+                "test", "test", VersionRange.createFromVersion("1.4"), null, "jar", "", new DefaultArtifactHandler()));
+
+        File file = new File(path);
+        file.getParentFile().mkdirs();
+        buildResourceBundle("default-useprojectfiles-create", null, new String[] {"FILTER.txt.vm"}, file);
+
+        setVariableValueToObject(mojo, "useProjectFiles", true);
+
+        mojo.execute();
+
+        File outputFile = new File((File) getVariableValueFromObject(mojo, "outputDirectory"), "FILTER.txt");
+        String data = FileUtils.fileRead(outputFile);
+        assertTrue(data.contains("local override: Test Project default-useprojectfiles"));
+    }
+
     public void testVelocityUTF8() throws Exception {
         final MavenProjectResourcesStub project = createTestProject("default-utf8");
         final ProcessRemoteResourcesMojo mojo = lookupProcessMojoWithSettings(project, new String[] {"test:test:1.2"});
@@ -246,7 +271,7 @@
         final ProcessRemoteResourcesMojo mojo =
                 lookupProcessMojoWithSettings(project, new String[] {"test-filtered-bundles:test-filtered-bundles:2"});
 
         mojo.includeProjectProperties = true;
         setupDefaultProject(project);
 
         project.addProperty("testingPropertyOne", "maven");
@@ -401,7 +426,7 @@
         localRepository.setLayout(new DefaultRepositoryLayout());
         request.setLocalRepository(localRepository);
         MavenSession session =
                 new MavenSession(getContainer(), reposession, request, new DefaultMavenExecutionResult());
         session.setProjects(Collections.singletonList(project));
 
         setVariableValueToObject(