binding: Wrap url_launcher's launchUrl

Author: gnprice

lib/model/binding.dart

@@ -1,9 +1,11 @@
 import 'package:flutter/foundation.dart';
+import 'package:url_launcher/url_launcher.dart' as url_launcher;
+export 'package:url_launcher/url_launcher.dart' show LaunchMode;
 
 import '../widgets/store.dart';
 import 'store.dart';
 
-/// A singleton service providing the app's data.
+/// A singleton service providing the app's data and use of Flutter plugins.
 ///
 /// Only one instance will be constructed in the lifetime of the app,
 /// by calling the `ensureInitialized` static method on a subclass.
@@ -62,13 +64,24 @@ abstract class ZulipBinding {
   /// In application code, use [GlobalStoreWidget.of] to get access
   /// to a [GlobalStore].
   Future<GlobalStore> loadGlobalStore();
+
+  /// Pass [url] to the underlying platform, via package:url_launcher.
+  ///
+  /// This wraps [url_launcher.launchUrl].
+  Future<bool> launchUrl(
+    Uri url, {
+    url_launcher.LaunchMode mode = url_launcher.LaunchMode.platformDefault,
+  });
 }
 
 /// A concrete binding for use in the live application.
 ///
 /// The global store returned by [loadGlobalStore], and consequently by
 /// [GlobalStoreWidget.of] in application code, will be a [LiveGlobalStore].
 /// It therefore uses a live server and live, persistent local database.
+///
+/// Methods wrapping a plugin, like [launchUrl], invoke the actual
+/// underlying plugin method.
 class LiveZulipBinding extends ZulipBinding {
   /// Initialize the binding if necessary, and ensure it is a [LiveZulipBinding].
   static LiveZulipBinding ensureInitialized() {
@@ -82,4 +95,12 @@ class LiveZulipBinding extends ZulipBinding {
   Future<GlobalStore> loadGlobalStore() {
     return LiveGlobalStore.load();
   }
+
+  @override
+  Future<bool> launchUrl(
+    Uri url, {
+    url_launcher.LaunchMode mode = url_launcher.LaunchMode.platformDefault,
+  }) {
+    return url_launcher.launchUrl(url, mode: mode);
+  }
 }

test/model/binding.dart

@@ -1,12 +1,14 @@
 import 'package:flutter/foundation.dart';
+import 'package:url_launcher/url_launcher.dart' as url_launcher;
 import 'package:zulip/model/binding.dart';
 import 'package:zulip/model/store.dart';
 
 import 'test_store.dart';
 
 /// A concrete binding for use in the `flutter test` environment.
 ///
-/// Tests that will mount a [GlobalStoreWidget] should initialize this binding
+/// Tests that will mount a [GlobalStoreWidget], or invoke a Flutter plugin,
+/// should initialize this binding
 /// by calling [ensureInitialized] at the start of the `main` method.
 ///
 /// Individual test functions that mount a [GlobalStoreWidget] may then use
@@ -41,37 +43,41 @@ class TestZulipBinding extends ZulipBinding {
     _instance = this;
   }
 
-  /// The current global store offered to a [GlobalStoreWidget].
-  ///
-  /// The store is created lazily when accessing this getter, or when mounting
-  /// a [GlobalStoreWidget].  The same store will continue to be provided until
-  /// a call to [reset].
-  ///
-  /// Tests that access this getter, or that mount a [GlobalStoreWidget],
-  /// should clean up by calling [reset].
-  TestGlobalStore get globalStore => _globalStore ??= TestGlobalStore(accounts: []);
-  TestGlobalStore? _globalStore;
-
-  bool _debugAlreadyLoaded = false;
-
   /// Reset all test data to a clean state.
   ///
-  /// Tests that mount a [GlobalStoreWidget], or that access [globalStore],
+  /// Tests that mount a [GlobalStoreWidget], or invoke a Flutter plugin,
+  /// or access [globalStore] or other methods on this class,
   /// should clean up by calling this method.  Typically this is done using
   /// [addTearDown], like `addTearDown(TestZulipBinding.instance.reset);`.
   void reset() {
     _globalStore?.dispose();
     _globalStore = null;
     assert(() {
-      _debugAlreadyLoaded = false;
+      _debugAlreadyLoadedStore = false;
       return true;
     }());
+
+    launchUrlResult = true;
+    _launchUrlCalls = null;
   }
 
+  /// The current global store offered to a [GlobalStoreWidget].
+  ///
+  /// The store is created lazily when accessing this getter, or when mounting
+  /// a [GlobalStoreWidget].  The same store will continue to be provided until
+  /// a call to [reset].
+  ///
+  /// Tests that access this getter, or that mount a [GlobalStoreWidget],
+  /// should clean up by calling [reset].
+  TestGlobalStore get globalStore => _globalStore ??= TestGlobalStore(accounts: []);
+  TestGlobalStore? _globalStore;
+
+  bool _debugAlreadyLoadedStore = false;
+
   @override
   Future<GlobalStore> loadGlobalStore() {
     assert(() {
-      if (_debugAlreadyLoaded) {
+      if (_debugAlreadyLoadedStore) {
         throw FlutterError.fromParts([
           ErrorSummary('The same test global store was loaded twice.'),
           ErrorDescription(
@@ -87,9 +93,37 @@ class TestZulipBinding extends ZulipBinding {
           ),
         ]);
       }
-      _debugAlreadyLoaded = true;
+      _debugAlreadyLoadedStore = true;
       return true;
     }());
     return Future.value(globalStore);
   }
+
+  /// The value that `ZulipBinding.instance.launchUrl()` should return.
+  ///
+  /// See also [takeLaunchUrlCalls].
+  bool launchUrlResult = true;
+
+  /// Consume the log of calls made to `ZulipBinding.instance.launchUrl()`.
+  ///
+  /// This returns a list of the arguments to all calls made
+  /// to `ZulipBinding.instance.launchUrl()` since the last call to
+  /// either this method or [reset].
+  ///
+  /// See also [launchUrlResult].
+  List<({Uri url, url_launcher.LaunchMode mode})> takeLaunchUrlCalls() {
+    final result = _launchUrlCalls;
+    _launchUrlCalls = null;
+    return result ?? [];
+  }
+  List<({Uri url, url_launcher.LaunchMode mode})>? _launchUrlCalls;
+
+  @override
+  Future<bool> launchUrl(
+    Uri url, {
+    url_launcher.LaunchMode mode = url_launcher.LaunchMode.platformDefault,
+  }) async {
+    (_launchUrlCalls ??= []).add((url: url, mode: mode));
+    return launchUrlResult;
+  }
 }