FORGE-1009: SetPlugin now removes variable if no value is provided

shell/src/main/java/org/jboss/forge/shell/plugins/builtin/SetPlugin.java

@@ -50,7 +50,14 @@ public void run(@Option(description = "varname",
       }
       else
       {
-         forge.setProperty(variable, Echo.tokensToString(value));
+         if (value == null)
+         {
+            forge.removeProperty(variable);
+         }
+         else
+         {
+            forge.setProperty(variable, Echo.tokensToString(value));
+         }
       }
    }
 

shell/src/test/java/org/jboss/forge/shell/plugins/builtin/SetPluginTest.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2013 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Eclipse Public License version 1.0, available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.jboss.forge.shell.plugins.builtin;
+
+import org.jboss.forge.test.AbstractShellTest;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class SetPluginTest extends AbstractShellTest
+{
+
+   @Test
+   public void testSetProperty() throws Exception
+   {
+      getShell().execute("set");
+      Assert.assertFalse(getOutput().contains("ABC=avalue"));
+      getShell().execute("set ABC avalue");
+      getShell().execute("set");
+      Assert.assertTrue(getOutput().contains("ABC=avalue"));
+   }
+
+   @Test
+   public void testRemoveProperty() throws Exception
+   {
+      getShell().execute("set ABC avalue");
+      getShell().execute("set");
+      Assert.assertTrue(getOutput().contains("ABC=avalue"));
+      resetOutput();
+      getShell().execute("set ABC");
+      getShell().execute("set");
+      Assert.assertFalse(getOutput().contains("ABC=avalue"));
+   }
+}