Added test for removing last row in cache

This is a test case for #8840 using TreeGrid.
Cannot be picked for 8.0.

2 files changed, 47 insertions, 1 deletions

diff --git a/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java
index bf373ccd2b..8f8a224049 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridBasicFeaturesTest.java
@@ -121,7 +121,7 @@ public class TreeGridBasicFeaturesTest extends MultiBrowserTest {
 
     @Override
     protected boolean useNativeEventsForIE() {
-        //Fixes IE11 selectMenuPath troubles
+        // Fixes IE11 selectMenuPath troubles
         return false;
     }
 
diff --git a/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridCollapseToLastRowInCacheTest.java b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridCollapseToLastRowInCacheTest.java
new file mode 100644
index 0000000000..f24fcc2e76
--- /dev/null
+++ b/uitest/src/test/java/com/vaadin/tests/components/treegrid/TreeGridCollapseToLastRowInCacheTest.java
@@ -0,0 +1,46 @@
+package com.vaadin.tests.components.treegrid;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.vaadin.testbench.elements.TreeGridElement;
+import com.vaadin.tests.tb3.SingleBrowserTest;
+
+public class TreeGridCollapseToLastRowInCacheTest extends SingleBrowserTest {
+
+    @Before
+    public void open() {
+        // need to remove more rows than what is in cache when collapsing
+        openTestURL("?restartApplication&debug&"
+                + TreeGridScrolling.NODES_PARAMETER + "=50");
+    }
+
+    @Override
+    protected Class<?> getUIClass() {
+        return TreeGridScrolling.class;
+    }
+
+    // #8840
+    @Test
+    public void testCollapsingNode_removesLastRowFromGridCache_noInternalError() {
+        TreeGridElement grid = $(TreeGridElement.class).first();
+
+        grid.expandWithClick(0);
+        grid.expandWithClick(1);
+
+        assertNoErrorNotifications();
+
+        Assert.assertEquals("0 | 0", grid.getCell(0, 0).getText());
+        Assert.assertEquals("1 | 0", grid.getCell(1, 0).getText());
+        Assert.assertEquals("2 | 0", grid.getCell(2, 0).getText());
+
+        grid.collapseWithClick(0);
+
+        Assert.assertEquals("0 | 0", grid.getCell(0, 0).getText());
+        Assert.assertEquals("0 | 1", grid.getCell(1, 0).getText());
+
+        assertNoErrorNotifications();
+    }
+
+}