Fix initial expand of TreeGrid items

Fixes #9050

2 files changed, 51 insertions, 0 deletions

diff --git a/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridInitialExpand.java b/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridInitialExpand.java
new file mode 100644
index 0000000000..db5b8c54b6
--- /dev/null
+++ b/uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridInitialExpand.java
@@ -0,0 +1,28 @@
+package com.vaadin.tests.components.treegrid;
+
+import com.vaadin.data.HierarchyData;
+import com.vaadin.data.provider.InMemoryHierarchicalDataProvider;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.TreeGrid;
+
+public class TreeGridInitialExpand extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        TreeGrid<String> treeGrid = new TreeGrid<>();
+        treeGrid.setCaption("Test");
+        treeGrid.addColumn(String::toString).setCaption("String");
+        HierarchyData<String> data = new HierarchyData<>();
+        data.addItem(null, "parent1");
+        data.addItem("parent1", "parent1-child1");
+        data.addItem("parent1", "parent1-child2");
+        data.addItem(null, "parent2");
+        data.addItem("parent2", "parent2-child2");
+        treeGrid.setDataProvider(new InMemoryHierarchicalDataProvider<>(data));
+        treeGrid.setHeightByRows(5);
+        treeGrid.expand("parent1");
+        treeGrid.expand("parent2");
+        addComponent(treeGrid);
+    }
+}
diff --git a/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridInitialExpandTest.java b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridInitialExpandTest.java
new file mode 100644
index 0000000000..d82155da6b
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridInitialExpandTest.java
@@ -0,0 +1,23 @@
+package com.vaadin.tests.components.treegrid;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.vaadin.testbench.elements.TreeGridElement;
+import com.vaadin.tests.tb3.SingleBrowserTest;
+
+public class TreeGridInitialExpandTest extends SingleBrowserTest {
+
+    @Test
+    public void initial_expand_of_items() {
+        openTestURL();
+        TreeGridElement grid = $(TreeGridElement.class).first();
+
+        assertEquals("parent1", grid.getCell(0, 0).getText());
+        assertEquals("parent1-child1", grid.getCell(1, 0).getText());
+        assertEquals("parent1-child2", grid.getCell(2, 0).getText());
+        assertEquals("parent2", grid.getCell(3, 0).getText());
+        assertEquals("parent2-child2", grid.getCell(4, 0).getText());
+    }
+}