feat: add feature to get maven module dependency graph (#151)

* feat: add feature to get maven module dependency graph

* Add maven model dependency

* Please spotless

* Rectify IntelliJ warnings

* Make names clearer

* Detect if there are submodule as dependency

* Please spotless

pom.xml

@@ -101,6 +101,11 @@
         <artifactId>asm-util</artifactId>
         <version>9.6</version>
       </dependency>
+      <dependency>
+        <groupId>org.apache.maven</groupId>
+        <artifactId>maven-model</artifactId>
+        <version>3.9.6</version>
+      </dependency>
     </dependencies>
   </dependencyManagement>
 

terminator-commons/pom.xml

@@ -60,6 +60,10 @@
       <artifactId>classgraph</artifactId>
       <version>4.8.165</version>
     </dependency>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-model</artifactId>
+    </dependency>
   </dependencies>
 
   <build>

terminator-commons/src/main/java/io/github/algomaster99/terminator/commons/maven/MavenModule.java

@@ -0,0 +1,96 @@
+package io.github.algomaster99.terminator.commons.maven;
+
+import java.nio.file.Path;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Queue;
+import org.apache.maven.model.Dependency;
+import org.apache.maven.model.Model;
+
+public class MavenModule {
+    private final MavenModule parent;
+
+    private final Model self;
+
+    private final Path fileSystemPath;
+
+    private final List<MavenModule> submodules = new ArrayList<>();
+
+    MavenModule(Model self, Path fileSystemPath, MavenModule parent) {
+        this.self = self;
+        this.fileSystemPath = fileSystemPath;
+        this.parent = parent;
+    }
+
+    public void addSubmodule(MavenModule child) {
+        submodules.add(child);
+    }
+
+    public Model getSelf() {
+        return self;
+    }
+
+    public List<MavenModule> getSubmodules() {
+        return submodules;
+    }
+
+    public Path getFileSystemPath() {
+        return fileSystemPath;
+    }
+
+    public MavenModule findSubmodule(String artifactIdOfModule) {
+        Queue<MavenModule> queue = new ArrayDeque<>();
+        queue.add(topLevelParent());
+        while (!queue.isEmpty()) {
+            MavenModule module = queue.poll();
+            if (module.getSelf().getArtifactId().equals(artifactIdOfModule)) {
+                return module;
+            }
+            queue.addAll(module.getSubmodules());
+        }
+        return null;
+    }
+
+    public MavenModule topLevelParent() {
+        if (parent == null) {
+            return this;
+        }
+        return parent.topLevelParent();
+    }
+
+    public List<Model> getSubmodulesThatAreDependencies() {
+        List<Model> subModulesThatAreDependencies = new ArrayList<>();
+        List<Dependency> dependencies = self.getDependencies();
+        for (Dependency dependency : dependencies) {
+            String artifactId = dependency.getArtifactId();
+            MavenModule submodule = findSubmodule(artifactId);
+            if (submodule == null) {
+                continue;
+            }
+            subModulesThatAreDependencies.add(submodule.getSelf());
+            submodule.getSubmodulesThatAreDependencies();
+        }
+        return subModulesThatAreDependencies;
+    }
+
+    /**
+     * This is delegated to {@link Model#equals(Object)}.
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null || getClass() != obj.getClass()) {
+            return false;
+        }
+        MavenModule that = (MavenModule) obj;
+        return self.equals(that.self);
+    }
+
+    @Override
+    public int hashCode() {
+        return self.hashCode();
+    }
+}

terminator-commons/src/main/java/io/github/algomaster99/terminator/commons/maven/MavenModuleDependencyGraph.java

@@ -0,0 +1,46 @@
+package io.github.algomaster99.terminator.commons.maven;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.List;
+import org.apache.maven.model.Model;
+import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
+import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
+
+public class MavenModuleDependencyGraph {
+    // create dependency graph of maven modules
+
+    public static MavenModule createMavenModuleGraph(Path projectRoot) throws IOException, XmlPullParserException {
+        Path rootPom = projectRoot.resolve("pom.xml");
+        MavenXpp3Reader reader = new MavenXpp3Reader();
+        Model rootModel = reader.read(new FileReader(rootPom.toFile()));
+
+        MavenModule root = new MavenModule(rootModel, projectRoot.toAbsolutePath(), null);
+
+        List<String> submodules = rootModel.getModules();
+
+        for (String module : submodules) {
+            Path modulePath = projectRoot.resolve(module);
+            MavenXpp3Reader moduleReader = new MavenXpp3Reader();
+            Model moduleModel = moduleReader.read(
+                    new FileReader(modulePath.resolve("pom.xml").toFile()));
+            MavenModule mavenModule = new MavenModule(moduleModel, modulePath, root);
+            if (moduleModel.getModules() != null) {
+                List<String> childModules = moduleModel.getModules();
+                List<MavenModule> children = childModules.stream()
+                        .map(childModule -> {
+                            try {
+                                return createMavenModuleGraph(modulePath.resolve(childModule));
+                            } catch (IOException | XmlPullParserException e) {
+                                throw new RuntimeException(e);
+                            }
+                        })
+                        .toList();
+                children.forEach(mavenModule::addSubmodule);
+            }
+            root.addSubmodule(mavenModule);
+        }
+        return root;
+    }
+}

terminator-commons/src/test/java/io/github/algomaster99/terminator/commons/maven/MavenModuleDependencyGraphTest.java

@@ -0,0 +1,114 @@
+package io.github.algomaster99.terminator.commons.maven;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.Set;
+import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
+import org.junit.jupiter.api.Test;
+
+public class MavenModuleDependencyGraphTest {
+    @Test
+    void createMavenModuleGraph_singleModule() throws XmlPullParserException, IOException {
+        // arrange
+        Path projectRoot =
+                Path.of("src/test/resources/maven-modules/single-module").toAbsolutePath();
+
+        // act
+        MavenModule root = MavenModuleDependencyGraph.createMavenModuleGraph(projectRoot);
+
+        // assert
+        assertThat(root).isNotNull();
+
+        assertThat(root.getSelf().getArtifactId()).isEqualTo("single-module");
+        assertThat(root.getFileSystemPath()).isEqualTo(projectRoot);
+        assertThat(root.getSubmodules()).hasSize(0);
+    }
+
+    @Test
+    void createMavenModuleGraph_multiModule_singleDepth() throws XmlPullParserException, IOException {
+        // arrange
+        Path projectRoot = Path.of("src/test/resources/maven-modules/multi-module-single-depth")
+                .toAbsolutePath();
+
+        // act
+        MavenModule root = MavenModuleDependencyGraph.createMavenModuleGraph(projectRoot);
+
+        // assert
+        assertThat(root).isNotNull();
+
+        assertThat(root.getSelf().getArtifactId()).isEqualTo("multi-module-single-depth");
+        assertThat(root.getFileSystemPath()).isEqualTo(projectRoot);
+        assertThat(root.getSubmodules()).hasSize(2);
+
+        MavenModule module1 = root.getSubmodules().get(0);
+        MavenModule module2 = root.getSubmodules().get(1);
+
+        assertThat(Set.of(module1.getSelf().getArtifactId(), module2.getSelf().getArtifactId()))
+                .contains("m1", "m2");
+        assertThat(Set.of(module1.getFileSystemPath(), module2.getFileSystemPath()))
+                .contains(projectRoot.resolve("m1"), projectRoot.resolve("m2"));
+
+        assertThat(module1.getSubmodules()).hasSize(0);
+        assertThat(module2.getSubmodules()).hasSize(0);
+    }
+
+    @Test
+    void createMavenModuleGraph_multiModule_multipleDepth() throws XmlPullParserException, IOException {
+        // arrange
+        Path projectRoot = Path.of("src/test/resources/maven-modules/multi-module-multiple-depth")
+                .toAbsolutePath();
+
+        // act
+        MavenModule root = MavenModuleDependencyGraph.createMavenModuleGraph(projectRoot);
+
+        // assert
+        assertThat(root).isNotNull();
+
+        assertThat(root.getSelf().getArtifactId()).isEqualTo("multi-module-multiple-depth");
+        assertThat(root.getFileSystemPath()).isEqualTo(projectRoot);
+        assertThat(root.getSubmodules()).hasSize(2);
+
+        MavenModule module1 = root.getSubmodules().get(0);
+        MavenModule module2 = root.getSubmodules().get(1);
+
+        assertThat(Set.of(module1.getSelf().getArtifactId(), module2.getSelf().getArtifactId()))
+                .contains("m1", "m2");
+        assertThat(Set.of(module1.getFileSystemPath(), module2.getFileSystemPath()))
+                .contains(projectRoot.resolve("m1"), projectRoot.resolve("m2"));
+
+        assertThat(module1.getSubmodules()).hasSize(0);
+        assertThat(module2.getSubmodules()).hasSize(1);
+
+        MavenModule module21 = module2.getSubmodules().get(0);
+
+        assertThat(module21.getSelf().getArtifactId()).isEqualTo("m21");
+        assertThat(module21.getFileSystemPath())
+                .isEqualTo(projectRoot.resolve("m2").resolve("m21"));
+        assertThat(module21.getSubmodules()).hasSize(0);
+    }
+
+    @Test
+    void createMavenModuleGraph_submoduleAsDependency() throws XmlPullParserException, IOException {
+        // arrange
+        Path projectRoot = Path.of("src/test/resources/maven-modules/submodule-as-dependency")
+                .toAbsolutePath();
+
+        // act
+        MavenModule root = MavenModuleDependencyGraph.createMavenModuleGraph(projectRoot);
+
+        // assert
+        assertThat(root).isNotNull();
+
+        assertThat(root.getSelf().getArtifactId()).isEqualTo("submodule-as-dependency");
+        assertThat(root.getFileSystemPath()).isEqualTo(projectRoot);
+        assertThat(root.getSubmodules()).hasSize(2);
+
+        MavenModule module1 = root.getSubmodules().get(0);
+        MavenModule module2 = root.getSubmodules().get(1);
+
+        assertThat(module1.getSubmodulesThatAreDependencies()).isEqualTo(List.of(module2.getSelf()));
+    }
+}

terminator-commons/src/test/resources/maven-modules/multi-module-multiple-depth/m1/pom.xml

@@ -0,0 +1,14 @@
+<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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.example</groupId>
+        <artifactId>multi-module-multiple-depth</artifactId>
+        <version>10.4.2</version>
+    </parent>
+
+    <artifactId>m1</artifactId>
+    <packaging>jar</packaging>
+    <version>10.4.2</version>
+</project>

terminator-commons/src/test/resources/maven-modules/multi-module-multiple-depth/m2/m21/pom.xml

@@ -0,0 +1,14 @@
+<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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.example</groupId>
+        <artifactId>m2</artifactId>
+        <version>10.4.2</version>
+    </parent>
+
+    <artifactId>m21</artifactId>
+    <packaging>jar</packaging>
+    <version>10.4.2</version>
+</project>

terminator-commons/src/test/resources/maven-modules/multi-module-multiple-depth/m2/pom.xml

@@ -0,0 +1,18 @@
+<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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.example</groupId>
+        <artifactId>multi-module-multiple-depth</artifactId>
+        <version>10.4.2</version>
+    </parent>
+
+    <artifactId>m2</artifactId>
+    <packaging>pom</packaging>
+    <version>10.4.2</version>
+
+    <modules>
+        <module>m21</module>
+    </modules>
+</project>

terminator-commons/src/test/resources/maven-modules/multi-module-multiple-depth/pom.xml

@@ -0,0 +1,14 @@
+<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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.example</groupId>
+    <artifactId>multi-module-multiple-depth</artifactId>
+    <packaging>pom</packaging>
+    <version>10.4.2</version>
+
+    <modules>
+        <module>m1</module>
+        <module>m2</module>
+    </modules>
+</project>

terminator-commons/src/test/resources/maven-modules/multi-module-single-depth/m1/pom.xml

@@ -0,0 +1,14 @@
+<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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.example</groupId>
+        <artifactId>multi-module-single-depth</artifactId>
+        <version>10.4.2</version>
+    </parent>
+
+    <artifactId>m1</artifactId>
+    <packaging>jar</packaging>
+    <version>10.4.2</version>
+</project>

terminator-commons/src/test/resources/maven-modules/multi-module-single-depth/m2/pom.xml

@@ -0,0 +1,14 @@
+<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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.example</groupId>
+        <artifactId>multi-module-single-depth</artifactId>
+        <version>10.4.2</version>
+    </parent>
+
+    <artifactId>m2</artifactId>
+    <packaging>jar</packaging>
+    <version>10.4.2</version>
+</project>

terminator-commons/src/test/resources/maven-modules/multi-module-single-depth/pom.xml

@@ -0,0 +1,14 @@
+<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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.example</groupId>
+    <artifactId>multi-module-single-depth</artifactId>
+    <packaging>pom</packaging>
+    <version>10.4.2</version>
+
+    <modules>
+        <module>m1</module>
+        <module>m2</module>
+    </modules>
+</project>