[webview_flutter_lwe] Add integration test based on upstream v4.13.1

Port the 'can receive url changes' NavigationDelegate test from upstream
webview_flutter v4.13.1, now runnable thanks to the onUrlChange implementation.

Other upstream tests not present in this suite remain omitted because the
lightweight web engine does not support the required features (custom request
headers, HTTP error status callback, HTTP basic auth, web storage clearing,
window.open, and media playback policy).

Author: seungsoo47

packages/webview_flutter_lwe/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 0.4.2
 
 * Implement `onUrlChange` for the navigation delegate.
+* Add 1 integration test case.
 
 ## 0.4.1
 

packages/webview_flutter_lwe/example/integration_test/webview_flutter_test.dart

@@ -447,6 +447,36 @@ Future<void> main() async {
       final String? currentUrl = await controller.currentUrl();
       expect(currentUrl, secondaryUrl);
     });
+
+    testWidgets('can receive url changes', (WidgetTester tester) async {
+      final Completer<void> pageLoaded = Completer<void>();
+
+      final WebViewController controller = WebViewController();
+      unawaited(controller.setJavaScriptMode(JavaScriptMode.unrestricted));
+      unawaited(
+        controller.setNavigationDelegate(
+          NavigationDelegate(onPageFinished: (_) => pageLoaded.complete()),
+        ),
+      );
+      unawaited(controller.loadRequest(Uri.parse(blankPageEncoded)));
+
+      await tester.pumpWidget(WebViewWidget(controller: controller));
+
+      await pageLoaded.future;
+
+      final Completer<String> urlChangeCompleter = Completer<String>();
+      await controller.setNavigationDelegate(
+        NavigationDelegate(
+          onUrlChange: (UrlChange change) {
+            urlChangeCompleter.complete(change.url);
+          },
+        ),
+      );
+
+      await controller.runJavaScript('location.href = "$primaryUrl"');
+
+      await expectLater(urlChangeCompleter.future, completion(primaryUrl));
+    });
   });
 }