fix: make ContextMenuTester open and close the menu like a real user

junit6/src/test/java/com/vaadin/flow/component/contextmenu/ContextMenuTesterTest.java

@@ -15,6 +15,7 @@
  */
 package com.vaadin.flow.component.contextmenu;
 
+import java.util.ArrayList;
 import java.util.List;
 
 import org.junit.jupiter.api.Assertions;
@@ -51,6 +52,19 @@ void openCloseMenu_menuIsAttachedAndDetached() {
                 "context menu should be detached from the UI, but was not");
     }
 
+    @Test
+    void openCloseMenu_openedChangeEventsComeFromClient() {
+        List<Boolean> fromClient = new ArrayList<>();
+        view.menu.addOpenedChangeListener(
+                event -> fromClient.add(event.isFromClient()));
+
+        test(view.menu).open();
+        test(view.menu).close();
+
+        Assertions.assertEquals(List.of(true, true), fromClient,
+                "opening and closing the menu should be reported as user actions");
+    }
+
     @Test
     void programmaticallyClose_menuIsDetached() {
         test(view.menu).open();
@@ -70,6 +84,23 @@ void openMenu_alreadyOpen_throws() {
         Assertions.assertTrue(exception.getMessage().contains("already open"));
     }
 
+    @Test
+    void openMenu_notUsable_throws() {
+        view.menu.setVisible(false);
+
+        IllegalStateException exception = Assertions.assertThrows(
+                IllegalStateException.class, test(view.menu)::open);
+        Assertions.assertTrue(exception.getMessage().contains("is not usable"));
+
+        Assertions.assertFalse(view.menu.isOpened(),
+                "a refused open should leave the menu closed");
+        Assertions.assertFalse(view.menu.isAttached(),
+                "a refused open should leave the menu detached from the UI");
+        Assertions.assertEquals(0,
+                find(Div.class).withText("Component Item").all().size(),
+                "a refused open should not leave the menu content reachable through a top level find()");
+    }
+
     @Test
     void closeMenu_menuNotOpened_throws() {
         Assertions.assertThrows(IllegalStateException.class,

junit6/src/test/java/com/vaadin/flow/component/grid/contextmenu/GridContextMenuTesterTest.java

@@ -190,6 +190,22 @@ void clickItem_disabledItem_throws() {
         Assertions.assertTrue(exception.getMessage().contains("not usable"));
     }
 
+    @Test
+    void openOnRow_menuNotUsable_throws() {
+        view.menu.setVisible(false);
+
+        IllegalStateException exception = Assertions.assertThrows(
+                IllegalStateException.class, () -> test(view.menu).open(0));
+        Assertions.assertTrue(exception.getMessage().contains("is not usable"));
+
+        Assertions.assertFalse(view.menu.isOpened(),
+                "a refused open should leave the menu closed");
+        Assertions.assertFalse(view.menu.isAttached(),
+                "a refused open should leave the menu detached from the UI");
+        Assertions.assertEquals(0, find(Checkbox.class).all().size(),
+                "a refused open should not leave the menu content reachable through a top level find()");
+    }
+
     @Test
     void clickItem_menuNotOpened_throws() {
         Assertions.assertThrows(IllegalStateException.class,

shared/src/main/java/com/vaadin/browserless/ComponentTester.java

@@ -186,6 +186,29 @@ public final void ensureComponentIsUsable() {
                 this::notUsableReasons);
     }
 
+    /**
+     * Checks that the wrapped component is usable and, if it is not, detaches
+     * it from the UI before rethrowing.
+     * <p>
+     * For an overlay the tester has to attach to the UI before it can tell
+     * whether it is usable, such as a context menu opened by a before-open
+     * event. Detaching it again keeps a refused interaction from leaving a
+     * closed overlay behind in the UI tree, where a top level {@code find(...)}
+     * would still reach its content.
+     *
+     * @throws IllegalStateException
+     *             if the component is not usable, with details on its current
+     *             state.
+     */
+    protected void ensureComponentIsUsableOrDetach() {
+        try {
+            ensureComponentIsUsable();
+        } catch (RuntimeException e) {
+            getComponent().getElement().removeFromParent();
+            throw e;
+        }
+    }
+
     /**
      * Throws an {@link IllegalStateException} with details on the current state
      * of the component if it is not usable according to the provided test.

shared/src/main/java/com/vaadin/flow/component/contextmenu/ContextMenuTester.java

@@ -80,16 +80,18 @@ public void open() {
         }
         attachMenuToUI();
         roundTrip();
-        getComponent().getElement().setProperty("opened", true);
-        ensureComponentIsUsable();
+        ensureComponentIsUsableOrDetach();
+        // Simulate the overlay reporting itself as opened so that the
+        // resulting OpenedChangeEvent is seen as a user action.
+        setPropertyAsUser("opened", true);
     }
 
     /**
      * Closes the context menu.
      */
     public void close() {
         ensureComponentIsUsable();
-        getComponent().getElement().setProperty("opened", false);
+        setPropertyAsUser("opened", false);
     }
 
     /**

shared/src/main/java/com/vaadin/flow/component/grid/contextmenu/GridContextMenuTester.java

@@ -168,11 +168,11 @@ public void open(int row, String columnKey) {
             throw new IllegalStateException(
                     "Context menu did not open. Its dynamic content handler returned false for the target row.");
         }
+        ensureComponentIsUsableOrDetach();
         // opened is a synchronized property, so pushing it through the
         // client path makes the GridContextMenuOpenedEvent report
         // isFromClient() as true, the way a real open does
         setPropertyAsUser("opened", true);
-        ensureComponentIsUsable();
     }
 
     /**