[url_launcher_web] Migrate to null-safety (flutter#3522)

This version uses auto-generated Mocks from mockito5 for its tests.

For now, tests only run in the `master` channel.

Co-authored-by: Maurits van Beusekom <maurits@baseflow.com>

analysis_options.yaml

@@ -4,6 +4,7 @@ analyzer:
     # Ignore generated files
     - '**/*.g.dart'
     - 'lib/src/generated/*.dart'
+    - '**/*.mocks.dart' # Mockito @GenerateMocks
   errors:
     always_require_non_null_named_parameters: false # not needed with nnbd
     unnecessary_null_comparison: false # Turned as long as nnbd mix-mode is supported.

packages/url_launcher/url_launcher_web/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 2.0.0-nullsafety
+
+- Migrate to null safety.
+
 # 0.1.5+3
 
 - Fix Link misalignment [issue](https://github.com/flutter/flutter/issues/70053).

packages/url_launcher/url_launcher_web/example/README.md

@@ -0,0 +1,31 @@
+# Testing
+
+This package utilizes the `integration_test` package to run its tests in a web browser.
+
+See [flutter.dev > Integration testing](https://flutter.dev/docs/testing/integration-tests) for more info.
+
+## Running the tests
+
+Make sure you have updated to the latest Flutter master.
+
+1. Check what version of Chrome is running on the machine you're running tests on.
+
+2. Download and install driver for that version from here:
+    * <https://chromedriver.chromium.org/downloads>
+
+3. Start the driver using `chromedriver --port=4444`
+
+4. Run tests: `flutter drive -d web-server --browser-name=chrome --driver=test_driver/integration_test_driver.dart --target=integration_test/TEST_NAME.dart`, or (in Linux):
+
+    * Single: `./run_test.sh integration_test/TEST_NAME.dart`
+    * All: `./run_test.sh`
+
+## Mocks
+
+There's `.mocks.dart` files next to the test files that use them.
+
+They're [generated by Mockito](https://github.com/dart-lang/mockito/blob/master/NULL_SAFETY_README.md#code-generation).
+
+Mocks might be manually re-generated with the following command: `flutter pub run build_runner build`. If there are any changes in the mocks, feel free to commit them.
+
+(Mocks will be auto-generated by the `run_test.sh` script as well.)

packages/url_launcher/url_launcher_web/example/build.yaml

@@ -0,0 +1,6 @@
+targets:
+  $default:
+    sources:
+      - integration_test/*.dart
+      - lib/$lib$
+      - $package$

packages/url_launcher/url_launcher_web/example/integration_test/link_widget_test.dart

@@ -0,0 +1,150 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:html' as html;
+import 'dart:js_util';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:url_launcher_platform_interface/link.dart';
+import 'package:url_launcher_web/src/link.dart';
+import 'package:integration_test/integration_test.dart';
+
+void main() {
+  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
+
+  group('Link Widget', () {
+    testWidgets('creates anchor with correct attributes',
+        (WidgetTester tester) async {
+      final Uri uri = Uri.parse('http://foobar/example?q=1');
+      await tester.pumpWidget(Directionality(
+        textDirection: TextDirection.ltr,
+        child: WebLinkDelegate(TestLinkInfo(
+          uri: uri,
+          target: LinkTarget.blank,
+          builder: (BuildContext context, FollowLink? followLink) {
+            return Container(width: 100, height: 100);
+          },
+        )),
+      ));
+      // Platform view creation happens asynchronously.
+      await tester.pumpAndSettle();
+
+      final html.Element anchor = _findSingleAnchor();
+      expect(anchor.getAttribute('href'), uri.toString());
+      expect(anchor.getAttribute('target'), '_blank');
+
+      final Uri uri2 = Uri.parse('http://foobar2/example?q=2');
+      await tester.pumpWidget(Directionality(
+        textDirection: TextDirection.ltr,
+        child: WebLinkDelegate(TestLinkInfo(
+          uri: uri2,
+          target: LinkTarget.self,
+          builder: (BuildContext context, FollowLink? followLink) {
+            return Container(width: 100, height: 100);
+          },
+        )),
+      ));
+      await tester.pumpAndSettle();
+
+      // Check that the same anchor has been updated.
+      expect(anchor.getAttribute('href'), uri2.toString());
+      expect(anchor.getAttribute('target'), '_self');
+    });
+
+    testWidgets('sizes itself correctly', (WidgetTester tester) async {
+      final Key containerKey = GlobalKey();
+      final Uri uri = Uri.parse('http://foobar');
+      await tester.pumpWidget(Directionality(
+        textDirection: TextDirection.ltr,
+        child: Center(
+          child: ConstrainedBox(
+            constraints: BoxConstraints.tight(Size(100.0, 100.0)),
+            child: WebLinkDelegate(TestLinkInfo(
+              uri: uri,
+              target: LinkTarget.blank,
+              builder: (BuildContext context, FollowLink? followLink) {
+                return Container(
+                  key: containerKey,
+                  child: SizedBox(width: 50.0, height: 50.0),
+                );
+              },
+            )),
+          ),
+        ),
+      ));
+      await tester.pumpAndSettle();
+
+      final Size containerSize = tester.getSize(find.byKey(containerKey));
+      // The Stack widget inserted by the `WebLinkDelegate` shouldn't loosen the
+      // constraints before passing them to the inner container. So the inner
+      // container should respect the tight constraints given by the ancestor
+      // `ConstrainedBox` widget.
+      expect(containerSize.width, 100.0);
+      expect(containerSize.height, 100.0);
+    });
+
+    // See: https://github.com/flutter/plugins/pull/3522#discussion_r574703724
+    testWidgets('uri can be null', (WidgetTester tester) async {
+      await tester.pumpWidget(Directionality(
+        textDirection: TextDirection.ltr,
+        child: WebLinkDelegate(TestLinkInfo(
+          uri: null,
+          target: LinkTarget.defaultTarget,
+          builder: (BuildContext context, FollowLink? followLink) {
+            return Container(width: 100, height: 100);
+          },
+        )),
+      ));
+      // Platform view creation happens asynchronously.
+      await tester.pumpAndSettle();
+
+      final html.Element anchor = _findSingleAnchor();
+      expect(anchor.hasAttribute('href'), false);
+    });
+  });
+}
+
+html.Element _findSingleAnchor() {
+  final List<html.Element> foundAnchors = <html.Element>[];
+  for (final html.Element anchor in html.document.querySelectorAll('a')) {
+    if (hasProperty(anchor, linkViewIdProperty)) {
+      foundAnchors.add(anchor);
+    }
+  }
+
+  // Search inside platform views with shadow roots as well.
+  for (final html.Element platformView
+      in html.document.querySelectorAll('flt-platform-view')) {
+    final html.ShadowRoot shadowRoot = platformView.shadowRoot!;
+    if (shadowRoot != null) {
+      for (final html.Element anchor in shadowRoot.querySelectorAll('a')) {
+        if (hasProperty(anchor, linkViewIdProperty)) {
+          foundAnchors.add(anchor);
+        }
+      }
+    }
+  }
+
+  return foundAnchors.single;
+}
+
+class TestLinkInfo extends LinkInfo {
+  @override
+  final LinkWidgetBuilder builder;
+
+  @override
+  final Uri? uri;
+
+  @override
+  final LinkTarget target;
+
+  @override
+  bool get isDisabled => uri == null;
+
+  TestLinkInfo({
+    required this.uri,
+    required this.target,
+    required this.builder,
+  });
+}