fix: fix Maven source and test source directory resolving

src/main/java/spoon/support/compiler/SpoonPom.java

@@ -35,6 +35,7 @@
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -165,9 +166,20 @@ public List<File> getSourceDirectories() {
 			sourcePath = build.getSourceDirectory();
 		}
 		if (sourcePath == null) {
-			sourcePath = Paths.get("src/main/java").toString();
+			sourcePath = getSourceDirectoryFromParent(getParentPom());
+			if (sourcePath == null) {
+				sourcePath = Paths.get("src/main/java").toString();
+			}
+		}
+		sourcePath = extractVariable(sourcePath);
+		Path path = Paths.get(sourcePath);
+
+		String absoluteSourcePath;
+		if (path.isAbsolute()) {
+			absoluteSourcePath = path.toString();
+		} else {
+			absoluteSourcePath = Paths.get(directory.getAbsolutePath(), sourcePath).toString();
 		}
-		String absoluteSourcePath = Paths.get(directory.getAbsolutePath(), sourcePath).toString();
 		File source = new File(absoluteSourcePath);
 		if (source.exists()) {
 			output.add(source);
@@ -182,6 +194,28 @@ public List<File> getSourceDirectories() {
 		return output;
 	}
 
+	/**
+	 * Climbs the pom.xml hierarchy until a model is found in which
+	 * a source directory is declared.
+	 * @return the uninterpolated source directory declared in the nearest ancestor
+	 */
+	private String getSourceDirectoryFromParent(SpoonPom parent) {
+		if (parent == null) {
+			return null;
+		}
+		String sourcePath = null;
+		Build build = parent.model.getBuild();
+		if (build != null) {
+			sourcePath = build.getSourceDirectory();
+			if (sourcePath == null && parent.getParentPom() != null) {
+				return getSourceDirectoryFromParent(parent.getParentPom());
+			}
+		} else if (parent.getParentPom() != null) {
+			return getSourceDirectoryFromParent(parent.getParentPom());
+		}
+		return sourcePath;
+	}
+
 	/**
 	 * Get the list of test directories of the project
 	 * @return the list of test directories
@@ -195,9 +229,20 @@ public List<File> getTestDirectories() {
 			sourcePath = build.getTestSourceDirectory();
 		}
 		if (sourcePath == null) {
-			sourcePath = Paths.get("src/test/java").toString();
+			sourcePath = getTestSourceDirectoryFromParent(getParentPom());
+			if (sourcePath == null) {
+				sourcePath = Paths.get("src/test/java").toString();
+			}
+		}
+		sourcePath = extractVariable(sourcePath);
+		Path path = Paths.get(sourcePath);
+
+		String absoluteSourcePath;
+		if (path.isAbsolute()) {
+			absoluteSourcePath = path.toString();
+		} else {
+			absoluteSourcePath = Paths.get(directory.getAbsolutePath(), sourcePath).toString();
 		}
-		String absoluteSourcePath = Paths.get(directory.getAbsolutePath(), sourcePath).toString();
 		File source = new File(absoluteSourcePath);
 		if (source.exists()) {
 			output.add(source);
@@ -212,6 +257,28 @@ public List<File> getTestDirectories() {
 		return output;
 	}
 
+	/**
+	 * Climbs the pom.xml hierarchy until a model is found in which
+	 * a test source directory is declared.
+	 * @return the uninterpolated test source directory declared in the nearest ancestor
+	 */
+	private String getTestSourceDirectoryFromParent(SpoonPom parent) {
+		if (parent == null) {
+			return null;
+		}
+		String sourcePath = null;
+		Build build = parent.model.getBuild();
+		if (build != null) {
+			sourcePath = build.getTestSourceDirectory();
+			if (sourcePath == null && parent.getParentPom() != null) {
+				return getTestSourceDirectoryFromParent(parent.getParentPom());
+			}
+		} else if (parent.getParentPom() != null) {
+			return getTestSourceDirectoryFromParent(parent.getParentPom());
+		}
+		return sourcePath;
+	}
+
 	/**
 	 * Get the list of classpath files generated by maven
 	 * @return the list of classpath files
@@ -247,29 +314,31 @@ private String extractVariable(String value) {
 	}
 
 	/**
-	 * Get the value of a property
+	 * Get the value of a property. Reference: https://maven.apache.org/ref/3.6.3/maven-model-builder/#Model_Interpolation
 	 * @param key the key of the property
 	 * @return the property value if key exists or null
 	 */
 	private String getProperty(String key) {
-		if ("project.version".equals(key)  || "pom.version".equals(key)) {
+		if ("project.version".equals(key) || "pom.version".equals(key) || "version".equals(key)) {
 			if (model.getVersion() != null) {
 				return model.getVersion();
 			} else if (model.getParent() != null) {
 				return model.getParent().getVersion();
 			}
-		} else if ("project.groupId".equals(key) || "pom.groupId".equals(key)) {
+		} else if ("project.groupId".equals(key) || "pom.groupId".equals(key) || "groupId".equals(key)) {
 			if (model.getGroupId() != null) {
 				return model.getGroupId();
 			} else if (model.getParent() != null) {
 				return model.getParent().getGroupId();
 			}
-		} else if ("project.artifactId".equals(key)  || "pom.artifactId".equals(key)) {
+		} else if ("project.artifactId".equals(key) || "pom.artifactId".equals(key) || "artifactId".equals(key)) {
 			if (model.getArtifactId() != null) {
 				return model.getArtifactId();
 			} else if (model.getParent() != null) {
 				return model.getParent().getArtifactId();
 			}
+		} else if ("project.basedir".equals(key) || "pom.basedir".equals(key) || "basedir".equals(key)) {
+			return pomFile.getParent();
 		}
 		String value = extractVariable(model.getProperties().getProperty(key));
 		if (value == null) {

src/test/java/spoon/support/compiler/SpoonPomTest.java

@@ -8,6 +8,7 @@
 import java.io.IOException;
 import java.util.List;
 import java.util.regex.Pattern;
+import java.nio.file.Paths;
 
 import static org.junit.Assert.*;
 
@@ -51,4 +52,20 @@ public void checkProfilesModules(String path, String[] expected, Pattern profile
 			assertEquals(expected[i], modules.get(i).getName());
 		}
 	}
+
+	public void getSourceDirectory() throws IOException, XmlPullParserException {
+		checkSourceDirectory(
+			"src/test/resources/maven-launcher/hierarchy",
+			Paths.get("src/test/resources/maven-launcher/hierarchy/child/src").toAbsolutePath().toString()
+		);
+	}
+
+	public void checkSourceDirectory(String path, String expected) throws IOException, XmlPullParserException {
+		SpoonPom pomModel = new SpoonPom(path, null, MavenLauncher.SOURCE_TYPE.APP_SOURCE, new StandardEnvironment());
+
+		SpoonPom childModel = pomModel.getModules().get(0);
+		//contract: source directory is derived from parent pom.xml if not declared in the current
+		// (childModel) SpoonPom
+		assertEquals(expected, childModel.getSourceDirectories().get(0).getAbsolutePath());
+	}
 }

src/test/resources/maven-launcher/hierarchy/child/pom.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+    <parent>
+        <groupId>sample.text</groupId>
+        <artifactId>parent</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>..</relativePath>
+    </parent>
+    <groupId>sample.text</groupId>
+    <artifactId>child</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+
+    <packaging>jar</packaging>
+</project>

src/test/resources/maven-launcher/hierarchy/child/src/Test.java

@@ -0,0 +1,5 @@
+package maven-launcher.hierarchy.child.src;
+
+public class Test {
+
+}

src/test/resources/maven-launcher/hierarchy/pom.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+    <parent>
+        <groupId>sample.text</groupId>
+        <artifactId>project</artifactId>
+        <version>2.2.2.RELEASE</version>
+        <relativePath/>
+    </parent>
+    <groupId>sample.text</groupId>
+    <artifactId>parent</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+
+    <packaging>pom</packaging>
+
+    <modules>
+        <module>child</module>
+    </modules>
+
+    <build>
+        <sourceDirectory>${project.basedir}/src</sourceDirectory>
+    </build>
+</project>