DevMojo: support managed dependencies for APT plugins

Related to quarkusio#37477 and quarkusio#37044

devtools/maven/src/main/java/io/quarkus/maven/DevMojo.java

@@ -31,6 +31,7 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Properties;
 import java.util.Scanner;
@@ -49,6 +50,7 @@
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.BuildBase;
 import org.apache.maven.model.Dependency;
+import org.apache.maven.model.DependencyManagement;
 import org.apache.maven.model.Plugin;
 import org.apache.maven.model.PluginExecution;
 import org.apache.maven.model.Profile;
@@ -715,6 +717,9 @@ private void executeGoal(PluginExec pluginExec, String goal, Map<String, String>
     }
 
     private List<String> readAnnotationProcessors(Xpp3Dom pluginConfig) {
+        if (pluginConfig == null) {
+            return Collections.emptyList();
+        }
         Xpp3Dom annotationProcessors = pluginConfig.getChild("annotationProcessors");
         if (annotationProcessors == null) {
             return Collections.emptyList();
@@ -731,6 +736,9 @@ private List<String> readAnnotationProcessors(Xpp3Dom pluginConfig) {
     }
 
     private Set<File> readAnnotationProcessorPaths(Xpp3Dom pluginConfig) throws MojoExecutionException {
+        if (pluginConfig == null) {
+            return Collections.emptySet();
+        }
         Xpp3Dom annotationProcessorPaths = pluginConfig.getChild("annotationProcessorPaths");
         if (annotationProcessorPaths == null) {
             return Collections.emptySet();
@@ -739,6 +747,10 @@ private Set<File> readAnnotationProcessorPaths(Xpp3Dom pluginConfig) throws Mojo
         Set<File> elements = new LinkedHashSet<>();
         try {
             List<org.eclipse.aether.graph.Dependency> dependencies = convertToDependencies(paths);
+            // NOTE: The Maven Compiler Plugin also supports a flag (disabled by default) for applying managed dependencies to
+            // the dependencies of the APT plugins (not them directly), which we don't support yet here
+            // you can find the implementation at https://github.com/apache/maven-compiler-plugin/pull/180/files#diff-d4bac42d8f4c68d397ddbaa05c1cbbed7984ef6dc0bb9ea60739df78997e99eeR1610
+            // when/if we need it
             CollectRequest collectRequest = new CollectRequest(dependencies, Collections.emptyList(),
                     project.getRemoteProjectRepositories());
             DependencyRequest dependencyRequest = new DependencyRequest();
@@ -756,25 +768,66 @@ private Set<File> readAnnotationProcessorPaths(Xpp3Dom pluginConfig) throws Mojo
         }
     }
 
-    private List<org.eclipse.aether.graph.Dependency> convertToDependencies(Xpp3Dom[] paths) {
+    private List<org.eclipse.aether.graph.Dependency> convertToDependencies(Xpp3Dom[] paths) throws MojoExecutionException {
         List<org.eclipse.aether.graph.Dependency> dependencies = new ArrayList<>();
         for (Xpp3Dom path : paths) {
             String type = getValue(path, "type", "jar");
             ArtifactHandler handler = artifactHandlerManager.getArtifactHandler(type);
+            // WATCH OUT: this constructor turns any null values into empty strings
             org.eclipse.aether.artifact.Artifact artifact = new DefaultArtifact(
                     getValue(path, "groupId", null),
                     getValue(path, "artifactId", null),
                     getValue(path, "classifier", null),
                     handler.getExtension(),
                     getValue(path, "version", null));
+            if (toNullIfEmpty(artifact.getVersion()) == null) {
+                artifact = artifact.setVersion(getAnnotationProcessorPathVersion(artifact));
+            }
             Set<org.eclipse.aether.graph.Exclusion> exclusions = convertToAetherExclusions(path.getChild("exclusions"));
             dependencies.add(new org.eclipse.aether.graph.Dependency(artifact, JavaScopes.RUNTIME, false, exclusions));
         }
         return dependencies;
     }
 
+    private String getAnnotationProcessorPathVersion(org.eclipse.aether.artifact.Artifact annotationProcessorPath)
+            throws MojoExecutionException {
+        List<Dependency> managedDependencies = getProjectManagedDependencies();
+        return findManagedVersion(annotationProcessorPath, managedDependencies)
+                .orElseThrow(() -> new MojoExecutionException(String.format(
+                        "Cannot find version for annotation processor path '%s'. The version needs to be either"
+                                + " provided directly in the plugin configuration or via dependency management.",
+                        annotationProcessorPath)));
+    }
+
+    private Optional<String> findManagedVersion(
+            org.eclipse.aether.artifact.Artifact artifact, List<Dependency> managedDependencies) {
+        // here, Dependency uses null, while artifact uses empty strings
+        return managedDependencies.stream()
+                .filter(dep -> Objects.equals(dep.getGroupId(), artifact.getGroupId())
+                        && Objects.equals(dep.getArtifactId(), artifact.getArtifactId())
+                        && Objects.equals(dep.getClassifier(), toNullIfEmpty(artifact.getClassifier()))
+                        && Objects.equals(dep.getType(), toNullIfEmpty(artifact.getExtension())))
+                .findAny()
+                .map(org.apache.maven.model.Dependency::getVersion);
+    }
+
+    private String toNullIfEmpty(String value) {
+        if (value != null && value.isBlank())
+            return null;
+        return value;
+    }
+
+    private List<Dependency> getProjectManagedDependencies() {
+        DependencyManagement dependencyManagement = project.getDependencyManagement();
+        if (dependencyManagement == null || dependencyManagement.getDependencies() == null) {
+            return Collections.emptyList();
+        }
+        return dependencyManagement.getDependencies();
+    }
+
     private String getValue(Xpp3Dom path, String element, String defaultValue) {
         Xpp3Dom child = path.getChild(element);
+        // don't bother filtering empty strings or null values, DefaultArtifact will turn nulls into empty strings
         if (child == null) {
             return defaultValue;
         }
@@ -1512,7 +1565,6 @@ private void setAnnotationProcessorFlags(MavenDevModeLauncher.Builder builder) {
                 break;
             }
         }
-
         if (compilerMavenPlugin == null) {
             return;
         }