jarek/7481: repr of scala unit object as MIMEContainer.HIDDEN

kernel/base/src/test/java/com/twosigma/beakerx/evaluator/EvaluatorBaseTest.java

@@ -100,6 +100,10 @@ public void returnPrintln() throws Exception {
     //when
     TryResult result = evaluator().evaluate(seo, code);
     //then
+    verifyReturnPrintlnStatement(result);
+  }
+
+  protected void verifyReturnPrintlnStatement(TryResult result) {
     assertThat((String) result.result()).isNull();
   }
 

kernel/scala/src/main/scala/com/twosigma/beakerx/scala/evaluator/ScalaEvaluatorGlue.scala

@@ -21,6 +21,7 @@ import java.net.URL
 import com.twosigma.beakerx.TryResult
 import com.twosigma.beakerx.autocomplete.AutocompleteResult
 import com.twosigma.beakerx.jvm.`object`.SimpleEvaluationObject
+import com.twosigma.beakerx.mimetype.MIMEContainer
 
 import scala.tools.jline_embedded.console.completer.Completer
 import scala.tools.nsc.Settings
@@ -119,8 +120,12 @@ class ScalaEvaluatorGlue(val cl: ClassLoader, var cp: String, val replClassdir:
       out.setOutputHandler()
       interpreter.interpret(code) match {
         case Success => {
-          val value = getOut.asInstanceOf[Object]
-          either = TryResult.createResult(value)
+          if (shouldHideResult()) {
+            either = TryResult.createResult(MIMEContainer.HIDDEN)
+          } else {
+            val value = getOut.asInstanceOf[Object]
+            either = TryResult.createResult(value)
+          }
         }
         case Incomplete => {
           either = TryResult.createError("input is incomplete")
@@ -139,6 +144,11 @@ class ScalaEvaluatorGlue(val cl: ClassLoader, var cp: String, val replClassdir:
     either
   }
 
+  private def shouldHideResult() = {
+    val print = interpreter.lastRequest.lineRep.call("$print").toString.trim
+    print.equals("")
+  }
+
   def autocomplete(buf: String, len: Integer): AutocompleteResult = {
     val maybes = new java.util.ArrayList[CharSequence]
     val offset = completer.complete(buf, len, maybes)

kernel/scala/src/test/java/com/twosigma/beakerx/scala/evaluator/ScalaBaseEvaluatorTest.java

@@ -15,13 +15,17 @@
  */
 package com.twosigma.beakerx.scala.evaluator;
 
+import com.twosigma.beakerx.TryResult;
 import com.twosigma.beakerx.evaluator.BaseEvaluator;
 import com.twosigma.beakerx.evaluator.EvaluatorBaseTest;
 import com.twosigma.beakerx.evaluator.TempFolderFactory;
+import com.twosigma.beakerx.mimetype.MIMEContainer;
 import com.twosigma.beakerx.scala.TestScalaEvaluator;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 public class ScalaBaseEvaluatorTest extends EvaluatorBaseTest {
 
   private static BaseEvaluator evaluator;
@@ -67,4 +71,9 @@ protected String codeForPrintln() {
     return "println(\"Hello\")";
   }
 
+  @Override
+  protected void verifyReturnPrintlnStatement(TryResult tryResult) {
+    assertThat(((MIMEContainer) tryResult.result())).isEqualTo(MIMEContainer.HIDDEN);
+  }
+
 }

kernel/scala/src/test/java/com/twosigma/beakerx/scala/evaluator/ScalaEvaluatorTest.java

@@ -18,13 +18,12 @@
 
 import com.twosigma.beakerx.TryResult;
 import com.twosigma.beakerx.chart.xychart.Plot;
-import com.twosigma.beakerx.kernel.KernelManager;
 import com.twosigma.beakerx.jvm.object.SimpleEvaluationObject;
 import com.twosigma.beakerx.kernel.EvaluatorParameters;
+import com.twosigma.beakerx.kernel.KernelManager;
 import com.twosigma.beakerx.kernel.PathToJar;
 import com.twosigma.beakerx.scala.TestScalaEvaluator;
 import com.twosigma.beakerx.scala.kernel.ScalaKernelMock;
-
 import com.twosigma.beakerx.widget.DisplayableWidget;
 import org.junit.After;
 import org.junit.AfterClass;

kernel/scala/src/test/java/com/twosigma/beakerx/scala/evaluator/ScalaReprTest.java

@@ -0,0 +1,83 @@
+/*
+ *  Copyright 2017 TWO SIGMA OPEN SOURCE, LLC
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package com.twosigma.beakerx.scala.evaluator;
+
+import com.twosigma.beakerx.TryResult;
+import com.twosigma.beakerx.jvm.object.SimpleEvaluationObject;
+import com.twosigma.beakerx.kernel.KernelManager;
+import com.twosigma.beakerx.mimetype.MIMEContainer;
+import com.twosigma.beakerx.scala.TestScalaEvaluator;
+import com.twosigma.beakerx.scala.kernel.ScalaKernelMock;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static com.twosigma.beakerx.MessageFactorTest.commMsg;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ScalaReprTest {
+
+  private static ScalaEvaluator scalaEvaluator;
+
+  @BeforeClass
+  public static void setUpClass() throws Exception {
+    scalaEvaluator = TestScalaEvaluator.evaluator();
+  }
+
+  @Before
+  public void setUp() throws Exception {
+    ScalaKernelMock kernel = new ScalaKernelMock("id", scalaEvaluator);
+    KernelManager.register(kernel);
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    KernelManager.register(null);
+  }
+
+  @AfterClass
+  public static void tearDownClass() throws Exception {
+    scalaEvaluator.exit();
+  }
+
+  @Test
+  public void unitObjectShouldBeRepresentedAsHIDDEN() {
+    //given
+    String code = "()";
+    SimpleEvaluationObject seo = new SimpleEvaluationObject(code);
+    seo.setJupyterMessage(commMsg());
+    //when
+    TryResult evaluate = scalaEvaluator.evaluate(seo, code);
+    //then
+    assertThat(((MIMEContainer) evaluate.result())).isEqualTo(MIMEContainer.HIDDEN);
+  }
+
+  @Test
+  public void emptyStringShouldBeRepresentedAsEmptyString() {
+    //given
+    String code = "\"\"";
+    SimpleEvaluationObject seo = new SimpleEvaluationObject(code);
+    seo.setJupyterMessage(commMsg());
+    //when
+    TryResult evaluate = scalaEvaluator.evaluate(seo, code);
+    //then
+    assertThat(evaluate.result()).isEqualTo("");
+  }
+}
+