Make it possible to reset single select values

Change-Id: I60c5d9f183d1955fbbd3341e3ac9f93aae755f80

1 files changed, 48 insertions, 0 deletions

diff --git a/server/src/test/java/com/vaadin/ui/ComboBoxTest.java b/server/src/test/java/com/vaadin/ui/ComboBoxTest.java
new file mode 100644
index 0000000000..36b29fdd7a
--- /dev/null
+++ b/server/src/test/java/com/vaadin/ui/ComboBoxTest.java
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2000-2016 Vaadin Ltd.
+ *
+ * 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.vaadin.ui;
+
+import org.junit.Test;
+
+import com.vaadin.shared.data.selection.SelectionServerRpc;
+import com.vaadin.tests.util.MockUI;
+
+public class ComboBoxTest {
+
+    @Test
+    public void testResetValue() {
+        ComboBox<String> comboBox = new ComboBox<>();
+        comboBox.setItems("one", "two");
+
+        // Reset value whenever it changes (in a real case, this listener would
+        // do something with the selected value before discarding it)
+        comboBox.addValueChangeListener(e -> comboBox.setValue(null));
+
+        // "Attach" the component and initialize diffstate
+        new MockUI().setContent(comboBox);
+        ComponentTest.syncToClient(comboBox);
+
+        // Emulate selection of "one"
+        String oneKey = comboBox.getDataCommunicator().getKeyMapper()
+                .key("one");
+        ComponentTest.getRpcProxy(comboBox, SelectionServerRpc.class)
+                .select(oneKey);
+
+        ComponentTest.assertEncodedStateProperties(comboBox,
+                "Selection change done by the listener should be sent to the client",
+                "selectedItemKey");
+    }
+}