first functional test made with FEST: simulation of user interaction with the IDE

found and solved a bug with caret positioning with a cleared editor (see #1288)

app/test/processing/app/ReplacingTextGeneratesTwoUndoActionsTest.java

@@ -0,0 +1,66 @@
+package processing.app;
+
+import org.fest.swing.core.ComponentMatcher;
+import org.fest.swing.fixture.FrameFixture;
+import org.fest.swing.fixture.JMenuItemFixture;
+import org.junit.Before;
+import org.junit.Test;
+import processing.app.syntax.JEditTextArea;
+
+import javax.swing.*;
+import java.awt.*;
+
+import static org.junit.Assert.assertEquals;
+
+public class ReplacingTextGeneratesTwoUndoActionsTest {
+
+  private FrameFixture window;
+  private Base base;
+
+  @Before
+  public void setUp() throws Exception {
+    Base.initPlatform();
+    Preferences.init(null);
+    JPopupMenu.setDefaultLightWeightPopupEnabled(false);
+    Theme.init();
+    Base.platform.setLookAndFeel();
+    Base.untitledFolder = Base.createTempFolder("untitled");
+    Base.untitledFolder.deleteOnExit();
+
+    base = new Base(new String[0]);
+    window = new FrameFixture(base.editors.get(0));
+  }
+
+  @Test
+  public void testName() throws Exception {
+    JMenuItemFixture menuEditUndo = window.menuItem("menuEditUndo");
+    menuEditUndo.requireDisabled();
+    JMenuItemFixture menuEditRedo = window.menuItem("menuEditRedo");
+    menuEditRedo.requireDisabled();
+
+    JEditTextArea jEditTextArea = (JEditTextArea) window.robot.finder().find(new ComponentMatcher() {
+      @Override
+      public boolean matches(Component component) {
+        return component instanceof JEditTextArea && "editor".equals(component.getName());
+      }
+    });
+
+    jEditTextArea.setText("fake text");
+
+    menuEditUndo.requireEnabled();
+    menuEditUndo.click();
+
+    assertEquals("", jEditTextArea.getText());
+
+    menuEditRedo.requireEnabled();
+    menuEditRedo.click();
+
+    assertEquals("fake text", jEditTextArea.getText());
+
+    menuEditUndo.requireEnabled();
+    menuEditUndo.click();
+    menuEditUndo.click();
+    menuEditUndo.requireDisabled();
+    menuEditRedo.requireEnabled();
+  }
+}