allow the maven plugin to have its source directories to be configured on a per execution basis (e.g. so that you can have different directories for JS compilation as to JVM based compilation). Its a shame to require 2 fields for configuration; but tried all other permutations I could think of but could not figure out a cleaner way -better approaches welcome! :)

libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/K2JSCompilerMojo.java

@@ -30,6 +30,7 @@ import org.jetbrains.k2js.config.MetaInfServices;
 import java.io.*;
 import java.nio.charset.Charset;
 import java.util.Arrays;
+import java.util.List;
 
 /**
  * Converts Kotlin to JavaScript code
@@ -163,6 +164,7 @@ public class K2JSCompilerMojo extends KotlinCompileMojo {
             if (verbose != null) {
                 k2jsArgs.verbose = verbose;
             }
+            List<String> sources = getSources();
             if (sources.size() > 0) {
                 k2jsArgs.sourceFiles = sources.toArray(new String[sources.size()]);
             }

libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/KotlinCompileMojo.java

@@ -32,7 +32,7 @@ public class KotlinCompileMojo extends KotlinCompileMojoBase {
     @Override
     protected void configureCompilerArguments(CompilerArguments arguments) throws MojoExecutionException {
         if (arguments instanceof K2JVMCompilerArguments) {
-            configureBaseCompilerArguments(getLog(), (K2JVMCompilerArguments) arguments, module, sources, classpath, output);
+            configureBaseCompilerArguments(getLog(), (K2JVMCompilerArguments) arguments, module, getSources(), classpath, output);
         }
     }
 }

libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/KotlinCompileMojoBase.java

@@ -39,17 +39,32 @@ import java.util.List;
 import static org.jetbrains.jet.internal.com.intellij.openapi.util.text.StringUtil.join;
 
 public abstract class KotlinCompileMojoBase extends AbstractMojo {
+
+
+    // TODO it would be nice to avoid using 2 injected fields for sources
+    // but I've not figured out how to have a defaulted parameter value
+    // which is also customisable inside an <execution> in a maven pom.xml
+    // so for now lets just use 2 fields
+
     /**
-     * The source directories containing the sources to be compiled.
+     * The default source directories containing the sources to be compiled.
      *
      * @parameter default-value="${project.compileSourceRoots}"
      * @required
-     * @readonly
      */
-    public List<String> sources;
+    private List<String> defaultSourceDirs;
 
-    // TODO not sure why this doesn't work :(
+    /**
-    // * @parameter default-value="$(project.basedir}/src/main/resources"
+     * The source directories containing the sources to be compiled.
+     *
+     * @parameter
+     */
+    private List<String> sourceDirs;
+
+    public List<String> getSources() {
+        if (sourceDirs != null && !sourceDirs.isEmpty()) return sourceDirs;
+        return defaultSourceDirs;
+    }
 
     /**
      * The directories used to scan for annotation.xml files for Kotlin annotations
@@ -58,14 +73,10 @@ public abstract class KotlinCompileMojoBase extends AbstractMojo {
      */
     public List<String> annotationPaths;
 
-    /**
+    // TODO not sure why this doesn't work :(
-     * The source directories containing the sources to be compiled for tests.
+    // * @parameter default-value="$(project.basedir}/src/main/resources"
-     *
+
-     * @parameter default-value="${project.testCompileSourceRoots}"
+
-     * @required
-     * @readonly
-     */
-    protected List<String> testSources;
 
     /**
      * Project classpath.
@@ -120,6 +131,7 @@ public abstract class KotlinCompileMojoBase extends AbstractMojo {
     @Override
     public void execute() throws MojoExecutionException, MojoFailureException {
         // Check sources
+        List<String> sources = getSources();
         if (sources != null && sources.size() > 0) {
             boolean sourcesExists = false;
 

libraries/tools/kotlin-maven-plugin/src/main/java/org/jetbrains/kotlin/maven/KotlinTestCompileMojo.java

@@ -21,6 +21,8 @@ import org.apache.maven.plugin.MojoFailureException;
 import org.jetbrains.jet.cli.common.CompilerArguments;
 import org.jetbrains.jet.cli.jvm.K2JVMCompilerArguments;
 
+import java.util.List;
+
 /**
  * Compiles Kotlin test sources
  *
@@ -38,6 +40,42 @@ public class KotlinTestCompileMojo extends KotlinCompileMojoBase {
      */
     private boolean skip;
 
+
+    // TODO it would be nice to avoid using 2 injected fields for sources
+    // but I've not figured out how to have a defaulted parameter value
+    // which is also customisable inside an <execution> in a maven pom.xml
+    // so for now lets just use 2 fields
+
+    /**
+     * The default source directories containing the sources to be compiled.
+     *
+     * @parameter default-value="${project.testCompileSourceRoots}"
+     * @required
+     */
+    private List<String> defaultSourceDirs;
+
+    /**
+     * The source directories containing the sources to be compiled.
+     *
+     * @parameter
+     */
+    private List<String> sourceDirs;
+
+    @Override
+    public List<String> getSources() {
+        if (sourceDirs != null && !sourceDirs.isEmpty()) return sourceDirs;
+        return defaultSourceDirs;
+    }
+
+    /**
+     * The source directories containing the sources to be compiled for tests.
+     *
+     * @parameter default-value="${project.testCompileSourceRoots}"
+     * @required
+     * @readonly
+     */
+    private List<String> defaultSourceDir;
+
     public void execute() throws MojoExecutionException, MojoFailureException {
         if (skip) {
             getLog().info("Test compilation is skipped");
@@ -52,7 +90,7 @@ public class KotlinTestCompileMojo extends KotlinCompileMojoBase {
         if (arguments instanceof K2JVMCompilerArguments) {
             configureBaseCompilerArguments(
                     getLog(), (K2JVMCompilerArguments) arguments,
-                    testModule, testSources, testClasspath, testOutput);
+                    testModule, getSources(), testClasspath, testOutput);
         }
     }
 }