[url_launcher] Url launcher platform interface null safety (#3142)

Author: mvanbeusekom

packages/url_launcher/url_launcher_platform_interface/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.0.0-nullsafety
+
+* Migrate to null safety.
+
 ## 1.0.8
 
 * Added webOnlyWindowName parameter

packages/url_launcher/url_launcher_platform_interface/analysis_options.yaml

@@ -0,0 +1,4 @@
+include: ../../../analysis_options.yaml
+analyzer:
+  enable-experiment:
+    - non-nullable

packages/url_launcher/url_launcher_platform_interface/lib/method_channel_url_launcher.dart

@@ -5,7 +5,6 @@
 import 'dart:async';
 
 import 'package:flutter/services.dart';
-import 'package:meta/meta.dart' show required;
 
 import 'url_launcher_platform_interface.dart';
 
@@ -18,7 +17,7 @@ class MethodChannelUrlLauncher extends UrlLauncherPlatform {
     return _channel.invokeMethod<bool>(
       'canLaunch',
       <String, Object>{'url': url},
-    );
+    ).then((value) => value ?? false);
   }
 
   @override
@@ -29,13 +28,13 @@ class MethodChannelUrlLauncher extends UrlLauncherPlatform {
   @override
   Future<bool> launch(
     String url, {
-    @required bool useSafariVC,
-    @required bool useWebView,
-    @required bool enableJavaScript,
-    @required bool enableDomStorage,
-    @required bool universalLinksOnly,
-    @required Map<String, String> headers,
-    String webOnlyWindowName,
+    required bool useSafariVC,
+    required bool useWebView,
+    required bool enableJavaScript,
+    required bool enableDomStorage,
+    required bool universalLinksOnly,
+    required Map<String, String> headers,
+    String? webOnlyWindowName,
   }) {
     return _channel.invokeMethod<bool>(
       'launch',
@@ -48,6 +47,6 @@ class MethodChannelUrlLauncher extends UrlLauncherPlatform {
         'universalLinksOnly': universalLinksOnly,
         'headers': headers,
       },
-    );
+    ).then((value) => value ?? false);
   }
 }

packages/url_launcher/url_launcher_platform_interface/lib/url_launcher_platform_interface.dart

@@ -4,7 +4,6 @@
 
 import 'dart:async';
 
-import 'package:meta/meta.dart' show required;
 import 'package:plugin_platform_interface/plugin_platform_interface.dart';
 
 import 'method_channel_url_launcher.dart';
@@ -49,13 +48,13 @@ abstract class UrlLauncherPlatform extends PlatformInterface {
   /// in `package:url_launcher/url_launcher.dart`.
   Future<bool> launch(
     String url, {
-    @required bool useSafariVC,
-    @required bool useWebView,
-    @required bool enableJavaScript,
-    @required bool enableDomStorage,
-    @required bool universalLinksOnly,
-    @required Map<String, String> headers,
-    String webOnlyWindowName,
+    required bool useSafariVC,
+    required bool useWebView,
+    required bool enableJavaScript,
+    required bool enableDomStorage,
+    required bool universalLinksOnly,
+    required Map<String, String> headers,
+    String? webOnlyWindowName,
   }) {
     throw UnimplementedError('launch() has not been implemented.');
   }

packages/url_launcher/url_launcher_platform_interface/pubspec.yaml

@@ -3,20 +3,24 @@ description: A common platform interface for the url_launcher plugin.
 homepage: https://github.com/flutter/plugins/tree/master/packages/url_launcher/url_launcher_platform_interface
 # NOTE: We strongly prefer non-breaking changes, even at the expense of a
 # less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
-version: 1.0.8
+version: 2.0.0-nullsafety
 
 dependencies:
   flutter:
     sdk: flutter
-  meta: ^1.0.5
-  plugin_platform_interface: ^1.0.1
+  # TODO (mvanbeusekom): use pub.dev once 1.10.0-nullsafety released.
+  plugin_platform_interface:
+    git:
+      url: https://github.com/flutter/plugins.git
+      ref: nnbd
+      path: packages/plugin_platform_interface
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
   mockito: ^4.1.1
-  pedantic: ^1.8.0
+  pedantic: ^1.10.0-nullsafety.1
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: '>=2.10.0-56.0.dev <3.0.0'
   flutter: ">=1.9.1+hotfix.4 <2.0.0"

packages/url_launcher/url_launcher_platform_interface/test/method_channel_url_launcher_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// TODO(mvanbeusekom): Remove once Mockito is migrated to null safety.
+// @dart = 2.9
 import 'package:mockito/mockito.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -41,6 +43,10 @@ void main() {
     final List<MethodCall> log = <MethodCall>[];
     channel.setMockMethodCallHandler((MethodCall methodCall) async {
       log.add(methodCall);
+
+      // Return null explicitly instead of relying on the implicit null
+      // returned by the method channel if no return statement is specified.
+      return null;
     });
 
     final MethodChannelUrlLauncher launcher = MethodChannelUrlLauncher();
@@ -61,6 +67,12 @@ void main() {
       );
     });
 
+    test('canLaunch should return false if platform returns null', () async {
+      final canLaunch = await launcher.canLaunch('http://example.com/');
+
+      expect(canLaunch, false);
+    });
+
     test('launch', () async {
       await launcher.launch(
         'http://example.com/',
@@ -269,6 +281,20 @@ void main() {
       );
     });
 
+    test('launch should return false if platform returns null', () async {
+      final launched = await launcher.launch(
+        'http://example.com/',
+        useSafariVC: true,
+        useWebView: false,
+        enableJavaScript: false,
+        enableDomStorage: false,
+        universalLinksOnly: false,
+        headers: const <String, String>{},
+      );
+
+      expect(launched, false);
+    });
+
     test('closeWebView default behavior', () async {
       await launcher.closeWebView();
       expect(

script/incremental_build.sh

@@ -25,6 +25,7 @@ CUSTOM_ANALYSIS_PLUGINS=(
   "plugin_platform_interface"
   "video_player/video_player_web"
   "google_maps_flutter/google_maps_flutter_web"
+  "url_launcher/url_launcher_platform_interface"
 )
 # Comma-separated string of the list above
 readonly CUSTOM_FLAG=$(IFS=, ; echo "${CUSTOM_ANALYSIS_PLUGINS[*]}")