Update test

Author: Renzo Olivares

packages/two_dimensional_scrollables/example/test/table_view/simple_table_test.dart

@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:two_dimensional_examples/table_view/simple_table.dart';
 
@@ -62,14 +64,64 @@ void main() {
 
     // Enable multi-cell selection and verify.
     await tester.tap(find.textContaining('Multi-Cell'));
-    await tester.pump();
+    await tester.pumpAndSettle();
+
+    // Find two adjacent cells.  Adjust these finders as needed for your specific layout.
+    final Finder cell1 = find.text('Tile c: 0, r: 0');
+    final Finder cell2 = find.text('Tile c: 1, r: 0');
+
+    final Offset cell1Center = tester.getCenter(cell1);
+    final Offset cell2Center = tester.getCenter(cell2);
+
+    // Long press and drag to select multiple cells.
+    final TestGesture gesture = await tester.startGesture(cell1Center);
+    await tester.pump(kLongPressTimeout);
+    await gesture.moveTo(cell2Center);
+    await gesture.up();
+    await tester.pumpAndSettle();
+
+    final RenderParagraph paragraph1 = tester.renderObject<RenderParagraph>(
+      find.descendant(of: cell1, matching: find.byType(RichText)),
+    );
+    final RenderParagraph paragraph2 = tester.renderObject<RenderParagraph>(
+      find.descendant(of: cell2, matching: find.byType(RichText)),
+    );
+    expect(paragraph1.selections.isEmpty, isFalse);
+    expect(paragraph2.selections.isEmpty, isFalse);
 
     // Enable single-cell selection and verify.
     await tester.tap(find.textContaining('Single-Cell'));
-    await tester.pump();
+    await tester.pumpAndSettle();
+
+    // Selection has been cleared.
+    expect(paragraph1.selections.isEmpty, isTrue);
+    expect(paragraph2.selections.isEmpty, isTrue);
+
+    // Selecting from cell1 to cell2 only selects cell1.
+    await gesture.down(cell1Center);
+    await tester.pump(kLongPressTimeout);
+    await gesture.moveTo(cell2Center);
+    await gesture.up();
+    await tester.pumpAndSettle();
+
+    expect(paragraph1.selections.isEmpty, isFalse);
+    expect(paragraph2.selections.isEmpty, isTrue);
 
     // Disable selection and verify.
     await tester.tap(find.text('Disabled'));
-    await tester.pump();
+    await tester.pumpAndSettle();
+
+    // Selection has been cleared.
+    expect(paragraph1.selections.isEmpty, isTrue);
+    expect(paragraph2.selections.isEmpty, isTrue);
+
+    // Long pressing should not select anything.
+    await gesture.down(cell1Center);
+    await tester.pump(kLongPressTimeout);
+    await gesture.up();
+    await tester.pumpAndSettle();
+
+    expect(paragraph1.selections.isEmpty, isTrue);
+    expect(paragraph2.selections.isEmpty, isTrue);
   });
 }