add ut for scala command arguments

src/main/java/scala_maven/ScalaMojoSupport.java

@@ -105,7 +105,7 @@ public abstract class ScalaMojoSupport extends AbstractMojo {
 
   /** Scala 's version to use. (property 'maven.scala.version' replaced by 'scala.version') */
   @Parameter(property = "scala.version")
-  private String scalaVersion;
+  protected String scalaVersion;
 
   /**
    * Organization/group ID of the Scala used in the project. Default value is 'org.scala-lang'. This
@@ -524,7 +524,7 @@ final JavaMainCaller getEmptyScalaCommand(final String mainClass) throws Excepti
    *     if you are invoking the REPL.
    * @return a {@link JavaMainCaller} to use to invoke the given command.
    */
-  private JavaMainCaller getEmptyScalaCommand(final String mainClass, final boolean forkOverride)
+  JavaMainCaller getEmptyScalaCommand(final String mainClass, final boolean forkOverride)
       throws Exception {
 
     // If we are deviating from the plugin settings, let the user know

src/test/java/scala_maven/ScalaMojoSupportTest.java

@@ -5,9 +5,15 @@
 package scala_maven;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
+import java.util.List;
 import org.junit.Test;
+import scala_maven_executions.JavaMainCaller;
+import scala_maven_executions.JavaMainCallerSupport;
 
 public class ScalaMojoSupportTest {
 
@@ -60,4 +66,99 @@ public void scala2_13_should_generate_non_prefixed_target() {
     assertEquals("11", ScalaMojoSupport.targetOption("11", new VersionNumber("2.13.8")));
     assertEquals("17", ScalaMojoSupport.targetOption("17", new VersionNumber("2.13.8")));
   }
+
+  static class ScalaMojoSupportWithRelease extends ScalaMojoSupport {
+    public ScalaMojoSupportWithRelease() {
+      this.release = "42";
+      this.target = "8";
+    }
+
+    public List<String> getScalacOptions() throws Exception {
+      try {
+        return super.getScalacOptions();
+      } catch (final Exception e) {
+        e.printStackTrace();
+        throw e;
+      }
+    }
+
+    public void setScalaVersion(final String v) {
+      this.scalaVersion = v;
+    }
+
+    @Override
+    protected void doExecute() throws Exception {}
+
+    @Override
+    JavaMainCaller getEmptyScalaCommand(final String mainClass, final boolean forkOverride) {
+      return new JavaMainCallerArgs(this);
+    }
+  }
+
+  static class JavaMainCallerArgs extends JavaMainCallerSupport {
+    public JavaMainCallerArgs(final ScalaMojoSupport mojo) {
+      super(mojo, null, null, null, null);
+    }
+
+    public List<String> getArgs() {
+      return this.args;
+    }
+
+    @Override
+    public scala_maven_executions.SpawnMonitor spawn(boolean displayCmd) throws Exception {
+      return null;
+    }
+
+    @Override
+    public boolean run(boolean displayCmd, boolean throwFailure) throws Exception {
+      return false;
+    }
+
+    @Override
+    public void redirectToLog() {}
+  }
+
+  final ScalaMojoSupportWithRelease mojoWithRelease = new ScalaMojoSupportWithRelease();
+
+  @Test
+  public void scala2_11_should_skip_release_option() throws Exception {
+    mojoWithRelease.setScalaVersion("2.11.0");
+    List<String> opts = mojoWithRelease.getScalacOptions();
+    assertNotNull(opts);
+    assertFalse(opts.contains("-release"));
+    assertFalse(opts.contains("42"));
+  }
+
+  @Test
+  public void scala2_12_should_skip_release_option() throws Exception {
+    mojoWithRelease.setScalaVersion("2.12.0");
+    List<String> opts = mojoWithRelease.getScalacOptions();
+    assertNotNull(opts);
+    assertTrue(opts.contains("-release"));
+    assertTrue(opts.contains("42"));
+  }
+
+  @Test
+  public void scala2_13_should_keep_release_option() throws Exception {
+    mojoWithRelease.setScalaVersion("2.13.0");
+    List<String> opts = mojoWithRelease.getScalacOptions();
+    assertNotNull(opts);
+    assertTrue(opts.contains("-release"));
+    assertTrue(opts.contains("42"));
+  }
+
+  @Test
+  public void scala2_12_scala_command_contain_target_and_release() throws Exception {
+    mojoWithRelease.setScalaVersion("2.12.0");
+    final JavaMainCaller caller = mojoWithRelease.getScalaCommand(true, "String");
+    assertNotNull(caller);
+    assertTrue(caller instanceof JavaMainCallerArgs);
+
+    final JavaMainCallerArgs callerJvm = (JavaMainCallerArgs) caller;
+    assertNotNull(callerJvm.getArgs());
+    assertEquals(3, callerJvm.getArgs().size());
+    assertTrue(callerJvm.getArgs().contains("-release"));
+    assertTrue(callerJvm.getArgs().contains("42"));
+    assertTrue(callerJvm.getArgs().contains("-target:jvm-1.8"));
+  }
 }