Handle generated empty string style names properly (#17335)

Change-Id: I1adce18f238fd4357b0eb1be68ebf7a3aaa6dd6e

3 files changed, 57 insertions, 1 deletions

diff --git a/uitest/src/com/vaadin/tests/components/grid/GridHeaderStyleNames.java b/uitest/src/com/vaadin/tests/components/grid/GridHeaderStyleNames.java
index 765cd01812..019850dabb 100644
--- a/uitest/src/com/vaadin/tests/components/grid/GridHeaderStyleNames.java
+++ b/uitest/src/com/vaadin/tests/components/grid/GridHeaderStyleNames.java
@@ -46,7 +46,7 @@ public class GridHeaderStyleNames extends AbstractTestUIWithLog {
                 .createContainer(100));
 
         ageHeaderCell = grid.getDefaultHeaderRow().getCell("age");
-
+        grid.getDefaultHeaderRow().setStyleName("foo");
         headerRow = grid.prependHeaderRow();
         mergedCityCountryCell = headerRow.join("city", "country");
         mergedCityCountryCell.setText("Merged cell");
diff --git a/uitest/src/com/vaadin/tests/components/grid/basicfeatures/GridBasicFeatures.java b/uitest/src/com/vaadin/tests/components/grid/basicfeatures/GridBasicFeatures.java
index 18f2d02e93..ecf3d53385 100644
--- a/uitest/src/com/vaadin/tests/components/grid/basicfeatures/GridBasicFeatures.java
+++ b/uitest/src/com/vaadin/tests/components/grid/basicfeatures/GridBasicFeatures.java
@@ -83,9 +83,13 @@ public class GridBasicFeatures extends AbstractComponentTest<Grid> {
     public static final String ROW_STYLE_GENERATOR_ROW_NUMBERS_FOR_3_OF_4 = "Row numbers for 3/4";
     public static final String ROW_STYLE_GENERATOR_NONE = "None";
     public static final String ROW_STYLE_GENERATOR_ROW_NUMBERS = "Row numbers";
+    public static final String ROW_STYLE_GENERATOR_EMPTY = "Empty string";
+    public static final String ROW_STYLE_GENERATOR_NULL = "Null";
     public static final String CELL_STYLE_GENERATOR_NONE = "None";
     public static final String CELL_STYLE_GENERATOR_PROPERTY_TO_STRING = "Property to string";
     public static final String CELL_STYLE_GENERATOR_SPECIAL = "Special for 1/4 Column 1";
+    public static final String CELL_STYLE_GENERATOR_EMPTY = "Empty string";
+    public static final String CELL_STYLE_GENERATOR_NULL = "Null";
     private static final int MANUALLY_FORMATTED_COLUMNS = 5;
     public static final int COLUMNS = 12;
     public static final int EDITABLE_COLUMNS = COLUMNS - 1;
@@ -514,6 +518,22 @@ public class GridBasicFeatures extends AbstractComponentTest<Grid> {
                         }
                     }
                 });
+        rowStyleGenerators.put(ROW_STYLE_GENERATOR_EMPTY,
+                new RowStyleGenerator() {
+
+                    @Override
+                    public String getStyle(RowReference rowReference) {
+                        return "";
+                    }
+                });
+        rowStyleGenerators.put(ROW_STYLE_GENERATOR_NULL,
+                new RowStyleGenerator() {
+
+                    @Override
+                    public String getStyle(RowReference rowReference) {
+                        return null;
+                    }
+                });
         cellStyleGenerators.put(CELL_STYLE_GENERATOR_NONE, null);
         cellStyleGenerators.put(CELL_STYLE_GENERATOR_PROPERTY_TO_STRING,
                 new CellStyleGenerator() {
@@ -539,6 +559,20 @@ public class GridBasicFeatures extends AbstractComponentTest<Grid> {
                         return propertyId.toString().replace(' ', '_');
                     }
                 });
+        cellStyleGenerators.put(CELL_STYLE_GENERATOR_EMPTY,
+                new CellStyleGenerator() {
+                    @Override
+                    public String getStyle(CellReference cellReference) {
+                        return "";
+                    }
+                });
+        cellStyleGenerators.put(CELL_STYLE_GENERATOR_NULL,
+                new CellStyleGenerator() {
+                    @Override
+                    public String getStyle(CellReference cellReference) {
+                        return null;
+                    }
+                });
 
         createSelectAction("Row style generator", "State", rowStyleGenerators,
                 CELL_STYLE_GENERATOR_NONE,
diff --git a/uitest/src/com/vaadin/tests/components/grid/basicfeatures/server/GridCellStyleGeneratorTest.java b/uitest/src/com/vaadin/tests/components/grid/basicfeatures/server/GridCellStyleGeneratorTest.java
index 643c61d90a..f013b76075 100644
--- a/uitest/src/com/vaadin/tests/components/grid/basicfeatures/server/GridCellStyleGeneratorTest.java
+++ b/uitest/src/com/vaadin/tests/components/grid/basicfeatures/server/GridCellStyleGeneratorTest.java
@@ -118,4 +118,26 @@ public class GridCellStyleGeneratorTest extends GridBasicFeaturesTest {
     private void selectCellStyleNameGenerator(String name) {
         selectMenuPath("Component", "State", "Cell style generator", name);
     }
+
+    @Test
+    public void testEmptyStringStyleGenerator() {
+        setDebug(true);
+        openTestURL();
+        selectCellStyleNameGenerator(GridBasicFeatures.CELL_STYLE_GENERATOR_EMPTY);
+        selectRowStyleNameGenerator(GridBasicFeatures.ROW_STYLE_GENERATOR_EMPTY);
+
+        assertFalse("Error notification was present",
+                isElementPresent(NotificationElement.class));
+    }
+
+    @Test
+    public void testNullStringStyleGenerator() {
+        setDebug(true);
+        openTestURL();
+        selectCellStyleNameGenerator(GridBasicFeatures.CELL_STYLE_GENERATOR_NULL);
+        selectRowStyleNameGenerator(GridBasicFeatures.ROW_STYLE_GENERATOR_NULL);
+
+        assertFalse("Error notification was present",
+                isElementPresent(NotificationElement.class));
+    }
 }