Add a regression test for Table's RowGenerator feature. (#12069)

* Add a regression test for Table's RowGenerator feature.

There used to be a TB2 test for this once upon a time, but for some
reason that never got converted into a TB3 test before getting removed.

uitest/src/test/java/com/vaadin/tests/components/table/TableGeneratedRowsTest.java

@@ -0,0 +1,167 @@
+package com.vaadin.tests.components.table;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import org.junit.Test;
+import org.openqa.selenium.By;
+import org.openqa.selenium.WebElement;
+
+import com.vaadin.testbench.TestBenchElement;
+import com.vaadin.testbench.elements.TableElement;
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+@SuppressWarnings("deprecation")
+public class TableGeneratedRowsTest extends MultiBrowserTest {
+
+    @Override
+    protected Class<?> getUIClass() {
+        return Tables.class;
+    }
+
+    @Test
+    public void changeRowGenerator() {
+        openTestURL();
+
+        TableElement table = $(TableElement.class).first();
+
+        /* No row generator */
+
+        TestBenchElement cell = table.getCell(4, 0);
+        int tableWidth = table.getSize().getWidth();
+        int cellWidth = cell.getSize().getWidth();
+        int buffer = 40; // for paddings, borders, scrollbars, and bit extra
+        int bufferedTableWidth = tableWidth - buffer;
+        String text = cell.getText();
+
+        assertFalse("Unexpected cell contents without applying row generator: "
+                + text, text != null && text.startsWith("FOOBARBAZ"));
+        assertLessThan(
+                "Cell shouldn't be spanned without applying row generator: "
+                        + cellWidth + " isn't less than " + (tableWidth / 10),
+                cellWidth, tableWidth / 10);
+
+        /* Spanned row generator */
+
+        selectMenuPath("Component", "Features", "Row generator",
+                "Every fifth row, spanned");
+
+        cell = table.getCell(4, 0);
+        cellWidth = cell.getSize().getWidth();
+        text = cell.getText();
+
+        assertTrue(
+                "Unexpected cell contents for spanned generated row: " + text,
+                text != null && text.startsWith("FOOBARBAZ"));
+        assertLessThanOrEqual(
+                "Spanned cell isn't wide enough for spanned generated row: "
+                        + cellWidth + " isn't more than " + bufferedTableWidth,
+                bufferedTableWidth, cellWidth);
+
+        /* Non-spanned row generator */
+
+        selectMenuPath("Component", "Features", "Row generator",
+                "Every tenth row, no spanning");
+
+        cell = table.getCell(4, 0);
+        cellWidth = cell.getSize().getWidth();
+        text = cell.getText();
+
+        assertFalse(
+                "Unexpected cell contents after replacing spanned row generator: "
+                        + text,
+                text != null && text.startsWith("FOOBARBAZ"));
+        assertLessThan(
+                "Cell shouldn't be spanned anymore after replacing spanned row generator: "
+                        + cellWidth + " isn't less than " + (tableWidth / 10),
+                cellWidth, tableWidth / 10);
+
+        cell = table.getCell(9, 0);
+        cellWidth = cell.getSize().getWidth();
+        text = cell.getText();
+
+        assertTrue("Unexpected cell contents for non-spanned generated row: "
+                + text, text != null && text.startsWith("FOO0"));
+        assertLessThan(
+                "Unexpected cell width for non-spanned generated row: "
+                        + cellWidth + " isn't less than " + (tableWidth / 10),
+                cellWidth, tableWidth / 10);
+
+        /* Spanned and html formatted row generator */
+
+        selectMenuPath("Component", "Features", "Row generator",
+                "Every eight row, spanned, html formatted");
+
+        cell = table.getCell(9, 0);
+        cellWidth = cell.getSize().getWidth();
+        text = cell.getText();
+
+        assertFalse(
+                "Unexpected cell contents after replacing non-spanned row generator: "
+                        + text,
+                text != null && text.startsWith("FOO0"));
+        assertLessThan(
+                "Unexpected cell width after replacing non-spanned row generator: "
+                        + cellWidth + " isn't less than " + (tableWidth / 10),
+                cellWidth, tableWidth / 10);
+
+        cell = table.getCell(7, 0);
+        cellWidth = cell.getSize().getWidth();
+        text = cell.getText();
+
+        assertTrue("Unexpected contents for spanned and html formatted cell: "
+                + text, text != null && text.startsWith("FOO BAR BAZ"));
+        assertLessThanOrEqual(
+                "Spanned and html formatted cell isn't wide enough: "
+                        + cellWidth + " isn't more than " + bufferedTableWidth,
+                bufferedTableWidth, cellWidth);
+
+        WebElement bazSpan = cell.findElement(By.tagName("span"));
+        if (bazSpan == null) {
+            fail("Unexpected styling: no span found");
+        } else {
+            String bazStyle = bazSpan.getAttribute("style");
+            assertTrue("Unexpected styling: " + bazStyle,
+                    bazStyle != null && bazStyle.contains("color: red"));
+        }
+
+        /* Spanned row generator for all rows */
+
+        selectMenuPath("Component", "Features", "Row generator",
+                "Every row, spanned");
+
+        for (int i = 0; i < 10; ++i) {
+            cell = table.getCell(i, 0);
+            cellWidth = cell.getSize().getWidth();
+            text = cell.getText();
+
+            assertTrue(
+                    "Unexpected cell contents with every row spanned: " + text,
+                    text != null && text.startsWith("SPANNED"));
+            assertLessThanOrEqual(
+                    "Spanned cell isn't wide enough with every row spanned: "
+                            + cellWidth + " isn't more than "
+                            + bufferedTableWidth,
+                    bufferedTableWidth, cellWidth);
+        }
+
+        /* No row generator */
+
+        selectMenuPath("Component", "Features", "Row generator", "None");
+
+        for (int i = 0; i < 10; ++i) {
+            cell = table.getCell(i, 0);
+            cellWidth = cell.getSize().getWidth();
+            text = cell.getText();
+
+            assertFalse(
+                    "Unexpected cell contents without row generator: " + text,
+                    text != null && text.startsWith("SPANNED"));
+            assertLessThan(
+                    "Unexpected cell width without row generator: " + cellWidth
+                            + " isn't less than " + (tableWidth / 10),
+                    cellWidth, tableWidth / 10);
+        }
+    }
+}