Fix no source root found issue with Scala 3 for multi-module projects

src/it/test_Scala3_multimodule/invoker.properties

@@ -0,0 +1 @@
+invoker.goals=clean verify site -e -ntp

src/it/test_Scala3_multimodule/module01/pom.xml

@@ -0,0 +1,17 @@
+<?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">
+
+    <parent>
+        <groupId>it.scoverage-maven-plugin</groupId>
+        <artifactId>test_Scala3_multimodule</artifactId>
+        <version>1.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>module01</artifactId>
+    <name>Test Scala 3 Multi-Module: Module 1</name>
+
+</project>

src/it/test_Scala3_multimodule/module01/src/main/scala/pkg01/HelloService1.scala

@@ -0,0 +1,12 @@
+package pkg01
+
+class HelloService1
+{
+  def hello: String =
+  {
+    "Hello from module 1"
+  }
+
+}
+
+object HelloService1 extends HelloService1

src/it/test_Scala3_multimodule/module01/src/test/scala/pkg01/HelloServiceTest.scala

@@ -0,0 +1,14 @@
+package pkg01
+
+import org.junit.Test;
+import org.junit.Assert.assertEquals
+
+class HelloServiceTest
+{
+    @Test
+    def test1(): Unit =
+    {
+        assertEquals("Hello from module 1", HelloService1.hello)
+    }
+
+}

src/it/test_Scala3_multimodule/pom.xml

@@ -0,0 +1,66 @@
+<?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/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>it.scoverage-maven-plugin</groupId>
+        <artifactId>integration_tests_parent</artifactId>
+        <version>1.0-SNAPSHOT</version>
+        <relativePath>../integration_tests_parent/pom.xml</relativePath>
+    </parent>
+
+    <artifactId>test_Scala3_multimodule</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>pom</packaging>
+    <name>Test Scala 3 Multi-Module</name>
+    <description>Test Scala 3 Multi-Module</description>
+
+    <properties>
+        <scala.compat.version>3</scala.compat.version>
+        <scala.version>3.3.1</scala.version>
+        <scala.library.artifact.id>scala3-library_3</scala.library.artifact.id>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <modules>
+        <module>module01</module>
+    </modules>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>net.alchim31.maven</groupId>
+                <artifactId>scala-maven-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>@project.groupId@</groupId>
+                <artifactId>@project.artifactId@</artifactId>
+                <configuration>
+                    <aggregate>true</aggregate> <!-- for aggregated report -->
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <reporting>
+        <plugins>
+            <plugin>
+                <groupId>@project.groupId@</groupId>
+                <artifactId>@project.artifactId@</artifactId>
+                <configuration>
+                    <aggregate>true</aggregate> <!-- for aggregated report -->
+                </configuration>
+            </plugin>
+        </plugins>
+    </reporting>
+</project>

src/it/test_Scala3_multimodule/validate.groovy

@@ -0,0 +1,20 @@
+try {
+
+    def module1ScoverageFile = new File(basedir, "module01/target/scoverage.xml")
+    assert module1ScoverageFile.exists()
+
+    def module1ReportFile = new File(basedir, "module01/target/site/scoverage/index.html")
+    assert module1ReportFile.exists()
+
+    def aggregatedScoverageFile = new File(basedir, "target/scoverage.xml")
+    assert aggregatedScoverageFile.exists()
+
+    def aggregatedReportFile = new File(basedir, "target/site/scoverage/index.html")
+    assert aggregatedReportFile.exists()
+
+    return true
+
+} catch (Throwable e) {
+    e.printStackTrace()
+    return false
+}

src/main/java/org/scoverage/plugin/SCoveragePreCompileMojo.java

@@ -33,6 +33,7 @@
 import org.apache.maven.artifact.resolver.ArtifactResolver;
 import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
+import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Dependency;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
@@ -155,6 +156,12 @@ public class SCoveragePreCompileMojo
     @Parameter( defaultValue = "${project}", readonly = true, required = true )
     private MavenProject project;
 
+    /**
+     * The current Maven session.
+     */
+    @Parameter( defaultValue = "${session}", readonly = true, required = true )
+    private MavenSession session;
+
     /**
      * All Maven projects in the reactor.
      */
@@ -283,7 +290,7 @@ public void execute() throws MojoExecutionException
             String _scalacOptions = quoteArgument( arg );
             String addScalacArgs = arg;
 
-            arg = scala2 ? ( SOURCE_ROOT_OPTION + project.getBasedir().getAbsolutePath() ) : "";
+            arg = scala2 ? ( SOURCE_ROOT_OPTION + session.getExecutionRootDirectory() ) : "";
             _scalacOptions = _scalacOptions + SPACE + quoteArgument( arg );
             addScalacArgs = addScalacArgs + PIPE + arg;
 

src/main/java/org/scoverage/plugin/SCoverageReportMojo.java

@@ -23,17 +23,16 @@
 import java.io.File;
 import java.io.FileInputStream;
 import java.util.ArrayList;
-import java.util.ArrayDeque;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
-import java.util.Queue;
 import java.util.ResourceBundle;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.maven.doxia.siterenderer.RenderingContext;
 import org.apache.maven.doxia.siterenderer.sink.SiteRendererSink;
 
+import org.apache.maven.execution.MavenSession;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugins.annotations.Execute;
@@ -58,7 +57,6 @@
 import scoverage.reporter.IOUtils;
 import scoverage.serialize.Serializer;
 import scoverage.reporter.CoberturaXmlWriter;
-import scoverage.reporter.CoverageAggregator;
 import scoverage.reporter.ScoverageHtmlWriter;
 import scoverage.reporter.ScoverageXmlWriter;
 
@@ -131,6 +129,12 @@ public class SCoverageReportMojo
     @Parameter( defaultValue = "${project}", readonly = true, required = true )
     private MavenProject project;
 
+    /**
+     * The current Maven session.
+     */
+    @Parameter(defaultValue = "${session}", readonly = true, required = true)
+    private MavenSession session;
+
     /**
      * All Maven projects in the reactor.
      */
@@ -423,7 +427,7 @@ private void generateReports()
 
         File coverageFile = Serializer.coverageFile( dataDirectory );
         getLog().info( String.format( "Reading scoverage instrumentation [%s]...", coverageFile.getAbsolutePath() ) );
-        Coverage coverage = Serializer.deserialize( coverageFile, project.getBasedir() );
+        Coverage coverage = Serializer.deserialize( coverageFile, executionRootDirectory() );
 
         getLog().info( String.format( "Reading scoverage measurements [%s*]...",
                                       new File( dataDirectory, Constants.MeasurementsPrefix() ).getAbsolutePath() ) );
@@ -444,22 +448,17 @@ private void generateAggregatedReports()
         AtomicInteger id = new AtomicInteger();
         List<File> scoverageDataDirs = new ArrayList<File>();
         List<File> sourceRoots = new ArrayList<File>();
-        MavenProject topLevelModule = null;
         for ( MavenProject module : reactorProjects )
         {
-            if ( module.isExecutionRoot() )
-            {
-                topLevelModule = module;
-            }
-            else if ( !module.getPackaging().equals( "pom" ) )
+            if ( !module.getPackaging().equals( "pom" ) )
             {
-                File scoverageDataDir = rebase( dataDirectory, module );
+                File scoverageDataDir = rebase( dataDirectory, module.getBasedir() );
                 if ( scoverageDataDir.isDirectory() )
                 {
                     scoverageDataDirs.add( scoverageDataDir );
                     File coverageFile = Serializer.coverageFile(scoverageDataDir);
                     if (coverageFile.exists()) {
-                        Coverage subCoverage  = Serializer.deserialize(coverageFile, module.getBasedir());
+                        Coverage subCoverage  = Serializer.deserialize(coverageFile, executionRootDirectory() );
                         List<File> measurementFiles = Arrays.asList( IOUtils.findMeasurementFiles( scoverageDataDir ) );
                         scala.collection.Set<Tuple2<Object, String>> measurements =
                                 IOUtils.invoked( CollectionConverters.asScala( measurementFiles ).toSeq(), encoding );
@@ -537,40 +536,15 @@ else if ( !module.getPackaging().equals( "pom" ) )
                     scoverageDataDirs.size() ) );
         }
 
-        /* traverse up the module tree until a module isExecutionRoot */
-        if ( topLevelModule == null )
-        {
-            Queue<MavenProject> candidateForTopLevelModules = new ArrayDeque<>(reactorProjects);
-            while ( !candidateForTopLevelModules.isEmpty() )
-            {
-                MavenProject module = candidateForTopLevelModules.poll();
-                if ( module.isExecutionRoot() )
-                {
-                    topLevelModule = module;
-                    break;
-                }
-                if ( module.hasParent() )
-                {
-                    candidateForTopLevelModules.add(module.getParent());
-                }
-            }
-        }
-        if ( topLevelModule == null )
-        {
-            // This exception should never be thrown.
-            throw new IllegalStateException("Cannot find the top level module to write the " +
-                    "aggregated reports.");
-        }
+        File executionRootOutputDirectory = rebase( outputDirectory, executionRootDirectory() );
+        File executionRootXmlOutputDirectory = rebase( xmlOutputDirectory, executionRootDirectory() );
 
-        File topLevelModuleOutputDirectory = rebase( outputDirectory, topLevelModule );
-        File topLevelModuleXmlOutputDirectory = rebase( xmlOutputDirectory, topLevelModule );
-
-        mkdirs( topLevelModuleOutputDirectory );
-        mkdirs( topLevelModuleXmlOutputDirectory );
+        mkdirs( executionRootOutputDirectory );
+        mkdirs( executionRootXmlOutputDirectory );
 
         getLog().info( "Generating coverage aggregated reports..." );
-        writeReports( coverage, sourceRoots, topLevelModuleXmlOutputDirectory, topLevelModuleXmlOutputDirectory,
-                      topLevelModuleOutputDirectory );
+        writeReports( coverage, sourceRoots, executionRootXmlOutputDirectory, executionRootXmlOutputDirectory,
+                      executionRootOutputDirectory );
         getLog().info( "Coverage aggregated reports completed." );
     }
 
@@ -610,10 +584,15 @@ else if ( directory.exists() && !directory.isDirectory() )
         }
     }
 
-    private File rebase( File file, MavenProject otherModule )
+    private File rebase( File file, File otherProjectDir )
     {
         return new File( file.getAbsolutePath().replace( project.getBasedir().getAbsolutePath(),
-                                                         otherModule.getBasedir().getAbsolutePath() ) );
+                                                         otherProjectDir.getAbsolutePath() ) );
+    }
+
+    private File executionRootDirectory()
+    {
+        return new File(session.getExecutionRootDirectory());
     }
 
 }