Added ability to provide arbitrary dependencies to properties mojo

src/main/java/org/apache/maven/plugins/dependency/PropertiesMojo.java

@@ -20,11 +20,13 @@
 
 import javax.inject.Inject;
 
+import java.util.List;
 import java.util.Set;
 
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugin.descriptor.PluginDescriptor;
 import org.apache.maven.plugins.annotations.LifecyclePhase;
 import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
@@ -68,7 +70,7 @@ public PropertiesMojo(MavenProject project) {
 
     /**
      * Main entry into mojo. Gets the list of dependencies and iterates through setting a property for each artifact.
-     *
+     * Gets the list of declared plugin's dependencies and iterates through setting a property for each artifact.
      * @throws MojoExecutionException with a message if an error occurs
      */
     @Override
@@ -86,6 +88,21 @@ public void execute() throws MojoExecutionException {
                             artifact.getDependencyConflictId(),
                             artifact.getFile().getAbsolutePath());
         }
+
+        PluginDescriptor pluginDescriptor = (PluginDescriptor) getPluginContext().get("pluginDescriptor");
+
+        if (pluginDescriptor != null) {
+            List<Artifact> pluginArtifacts = pluginDescriptor.getArtifacts();
+
+            if (pluginArtifacts != null) {
+                for (Artifact artifact : pluginArtifacts) {
+                    this.project.getProperties()
+                            .setProperty(
+                                    artifact.getDependencyConflictId(),
+                                    artifact.getFile().getAbsolutePath());
+                }
+            }
+        }
     }
 
     /**

src/test/java/org/apache/maven/plugins/dependency/TestPropertiesMojo.java

@@ -19,10 +19,14 @@
 package org.apache.maven.plugins.dependency;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Set;
 
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.execution.MavenSession;
+import org.apache.maven.plugin.descriptor.PluginDescriptor;
 import org.apache.maven.plugins.dependency.testUtils.stubs.DependencyProjectStub;
 import org.apache.maven.project.MavenProject;
 
@@ -77,4 +81,37 @@ public void testSetProperties() throws Exception {
             assertTrue(artifactFile.isFile());
         }
     }
+
+    /**
+     * tests the proper discovery and configuration of the mojo for plugin dependencies
+     * Each plugin dependency should set a property in the project
+     * @throws Exception in case of errors
+     */
+    public void testSetPropertiesForPluginDependencies() throws Exception {
+        File testPom = new File(getBasedir(), "target/test-classes/unit/properties-test/plugin-config.xml");
+        PropertiesMojo mojo = (PropertiesMojo) lookupMojo("properties", testPom);
+
+        assertNotNull(mojo);
+        MavenProject project = (MavenProject) getVariableValueFromObject(mojo, "project");
+        assertNotNull(project);
+
+        Set<Artifact> artifacts = this.stubFactory.getScopedArtifacts();
+        Set<Artifact> directArtifacts = this.stubFactory.getReleaseAndSnapshotArtifacts();
+        artifacts.addAll(directArtifacts);
+
+        PluginDescriptor pluginDescriptor = new PluginDescriptor();
+        pluginDescriptor.setArtifacts(new ArrayList<>());
+        Map pluginContext = new HashMap<>();
+        pluginContext.put("pluginDescriptor", pluginDescriptor);
+        mojo.setPluginContext(pluginContext);
+
+        mojo.execute();
+
+        for (Artifact artifact : artifacts) {
+            File artifactFile = artifact.getFile();
+            String depId = artifact.getDependencyConflictId();
+            assertTrue(project.getProperties().containsKey(depId));
+            assertTrue(project.getProperties().getProperty(depId).equals(artifactFile.getAbsolutePath()));
+        }
+    }
 }