Merge pull request #221 from e1121208/improve-code-coverage-to-the-ma…

…ximum

Improve CommandBoxUiTest test

src/test/java/seedu/address/ui/CommandBoxUiTest.java

@@ -2,6 +2,8 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static seedu.address.ui.CommandBox.ERROR_STYLE_CLASS;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -73,4 +75,15 @@ public void commandNavigationWorks_success() {
             robot.type(KeyCode.DOWN);
         }
     }
+    @Test
+    public void setStyleToIndicateCommandFailure_addsErrorStyleClass() {
+        FxRobot robot = new FxRobot();
+
+        assertNotNull(robot.lookup("#commandTextField"), "Command box should be present.");
+        robot.clickOn("#commandTextField");
+        robot.write("UNKNOWN COMMMAND");
+        robot.type(KeyCode.ENTER);
+        assertTrue(robot.lookup("#commandTextField").query().getStyleClass().contains(ERROR_STYLE_CLASS));
+    }
+
 }