add testbench api

vaadin-grid-flow-parent/vaadin-grid-flow-integration-tests/src/main/java/com/vaadin/flow/component/grid/it/GridEmptyStatePage.java

@@ -0,0 +1,32 @@
+package com.vaadin.flow.component.grid.it;
+
+import com.vaadin.flow.component.button.Button;
+import com.vaadin.flow.component.grid.Grid;
+import com.vaadin.flow.component.html.Div;
+import com.vaadin.flow.data.bean.Person;
+import com.vaadin.flow.router.Route;
+
+@Route("vaadin-grid/empty-state")
+public class GridEmptyStatePage extends Div {
+    public GridEmptyStatePage() {
+        var grid = new Grid<>(Person.class);
+        add(grid);
+
+        // Button to set the empty state content
+        var setEmptyStateContentButton = new Button("Set empty state content",
+                event -> grid.setEmptyStateText("Custom empty state content"));
+        setEmptyStateContentButton.setId("set-empty-state-content");
+
+        // Button to set the grid items
+        var setItemsButton = new Button("Set items", event -> grid
+                .setItems(new Person("John", 20), new Person("Jane", 30)));
+        setItemsButton.setId("set-items");
+
+        // Button to clear the grid items
+        var clearItemsButton = new Button("Clear items",
+                event -> grid.setItems());
+        clearItemsButton.setId("clear-items");
+
+        add(setEmptyStateContentButton, setItemsButton, clearItemsButton);
+    }
+}

vaadin-grid-flow-parent/vaadin-grid-flow-integration-tests/src/test/java/com/vaadin/flow/component/grid/it/GridEmptyStateIT.java

@@ -0,0 +1,61 @@
+package com.vaadin.flow.component.grid.it;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.openqa.selenium.NoSuchElementException;
+
+import com.vaadin.flow.component.button.testbench.ButtonElement;
+import com.vaadin.flow.component.grid.testbench.GridElement;
+import com.vaadin.flow.testutil.TestPath;
+import com.vaadin.tests.AbstractComponentIT;
+
+@TestPath("vaadin-grid/empty-state")
+public class GridEmptyStateIT extends AbstractComponentIT {
+    private GridElement grid;
+    private ButtonElement setEmptyStateContentButton;
+    private ButtonElement clearItemsButton;
+    private ButtonElement setItemsButton;
+
+    @Before
+    public void init() {
+        open();
+        grid = $(GridElement.class).first();
+        setEmptyStateContentButton = $(ButtonElement.class)
+                .id("set-empty-state-content");
+        clearItemsButton = $(ButtonElement.class).id("clear-items");
+        setItemsButton = $(ButtonElement.class).id("set-items");
+    }
+
+    @Test
+    public void getEmptyStateContent_throws() {
+        Assert.assertThrows("No empty state content was found",
+                NoSuchElementException.class,
+                () -> grid.getEmptyStateContent());
+    }
+
+    @Test
+    public void setEmptyStateContent_emptyStateContentDisplayed() {
+        setEmptyStateContentButton.click();
+        var content = grid.getEmptyStateContent();
+        Assert.assertEquals("Custom empty state content", content.getText());
+        Assert.assertTrue(content.isDisplayed());
+    }
+
+    @Test
+    public void setEmptyStateContent_setItems_emptyStateContentNotDisplayed() {
+        setEmptyStateContentButton.click();
+        setItemsButton.click();
+        var content = grid.getEmptyStateContent();
+        Assert.assertFalse(content.isDisplayed());
+    }
+
+    @Test
+    public void setEmptyStateContent_setItems_clearItems_emptyStateContentDisplayed() {
+        setEmptyStateContentButton.click();
+        setItemsButton.click();
+        clearItemsButton.click();
+        var content = grid.getEmptyStateContent();
+        Assert.assertTrue(content.isDisplayed());
+    }
+}

vaadin-grid-flow-parent/vaadin-grid-testbench/src/main/java/com/vaadin/flow/component/grid/testbench/GridElement.java

@@ -499,4 +499,19 @@ public List<GridTHTDElement> getCells(int rowIndex) {
                 getAllColumns().toArray(new GridColumnElement[0]));
     }
 
+    /**
+     * Gets the empty state content.
+     *
+     * @return the empty state content
+     * @throws NoSuchElementException
+     *             if no empty state content was found
+     */
+    public TestBenchElement getEmptyStateContent() {
+        try {
+            return findElement(By.cssSelector("[slot='empty-state']"));
+        } catch (NoSuchElementException e) {
+            throw new NoSuchElementException(
+                    "No empty state content was found");
+        }
+    }
 }