wafrat

Using SharedPreferences in tests

wafrat — Sun, 04 Jan 2026 03:45:54 GMT

SharedPreferences actually provides an in-memory implementation, but it is not documented in the README. If you don't set it up, SharedPreferences throws a warning when it's used in tests:

MissingPluginException(No implementation found for method getAll on channel plugins.flutter.io/shared_preferences)

The solution is to run SharedPreferences.setMockInitialValues({ values }).

setMockInitialValues method - SharedPreferences class - shared_preferences library - Dart API

API docs for the setMockInitialValues method from the SharedPreferences class, for the Dart programming language.

Dart API

I wish it was prominently shown in the package docs.

I did find a mention of it here: https://docs.flutter.dev/cookbook/persistence/key-value#testing-support

This ticket seems to say the method is deprecated, but as of today, it runs fine.

Mocking http.Client (updated)

wafrat — Sun, 04 Jan 2026 02:26:40 GMT

In the previous post from 2022, we already saw that we can use Mockito with @GenerateNiceMocks to generate a MockClient, or use http's own MockClient and pass it to classes. But what if the code is from a package that does not accept a Client?

Investigation

In that case we can't easily pass a mock Client. Let's look at the code that will run with the test:

var response = await http.get(Uri.parse(url), headers: allHeaders);

If we dig into http's code, we see:

Future get(Uri url, {Map? headers}) =>
    _withClient((client) => client.get(url, headers: headers));


Future _withClient(Future Function(Client) fn) async {
  var client = Client();
  try {
    return await fn(client);
  } finally {
    client.close();
  }
}


abstract interface class Client {
  /// Creates a new platform appropriate client.
  ///
  /// Creates an `IOClient` if `dart:io` is available and a `BrowserClient` if
  /// `dart:js_interop` is available, otherwise it will throw an unsupported
  /// error.
  factory Client() => zoneClient ?? createClient();

  ...
}

@internal
Client? get zoneClient {
  final client = Zone.current[#_clientToken];
  return client == null ? null : (client as Client Function())();
}


/// Runs [body] in its own [Zone] with the [Client] returned by [clientFactory]
/// set as the default [Client].
/// [...]
/// > [!IMPORTANT]
/// > Flutter does not guarantee that callbacks are executed in a particular
/// > [Zone].
/// >
/// > Instead of using [runWithClient], Flutter developers can use a framework,
/// > such as [`package:provider`](https://pub.dev/packages/provider), to make
/// > a [Client] available throughout their applications.
/// >
/// > See the
/// > [Flutter Http Example](https://github.com/dart-lang/http/tree/master/pkgs/flutter_http_example).
R runWithClient(R Function() body, Client Function() clientFactory,
        {ZoneSpecification? zoneSpecification}) =>
    runZoned(body,
        zoneValues: {#_clientToken: Zone.current.bindCallback(clientFactory)},
        zoneSpecification: zoneSpecification);

http

`runWithClient`

Here's how I used runWithClient to pass my MockClient:

await http.runWithClient(
  () async {
    await tester.pumpWidget(
      MaterialApp(
        home: Scaffold(
          body: Provider(
            create: (_) => MockFirebaseAuth(),
            child: Provider(
              create: (_) => MockChatService(),
              child: BubbleWidget(b),
            ),
          ),
        ),
      ),
    );
  },
  () => MockClient((request) async {
    final content = File('test/airtag.html').readAsStringSync();
    return http.Response(
      content,
      200,
      headers: {'content-type': 'text/html'},
    );
  }),
);

`content-type`

I can see that my MockClient callback is executed but I get this exception when initializing Response:

[package_name] - Error in https://www.[site].com/[some_article].html response (Invalid argument (string): Contains invalid characters.: "

I can see that readAsStringSync() reads in utf-8 by default, so content is fine. Should I add content-type to the headers?

I tried with headers: {'content-type': 'text/html', 'charset': 'utf-8'}, but it failed too.

Later when I googled some more, I found a post that set it up like this: headers: {'content-type': 'text/html; charset=utf-8'}. And sure enough, this worked.

Looking back, if I had carefully read the documentation, I'd have found out myself:

/// An HTTP response where the entire response body is known in advance.
class Response extends BaseResponse {
  /// The bytes comprising the body of this response.
  final Uint8List bodyBytes;

  /// The body of the response as a string.
  ///
  /// This is converted from [bodyBytes] using the `charset` parameter of the
  /// `Content-Type` header field, if available. If it's unavailable or if the
  /// encoding name is unknown:
  /// - [utf8] is used when the content-type is 'application/json' (see [RFC 3629][]).
  /// - [latin1] is used in all other cases (see [RFC 2616][])
  ///
  /// [RFC 3629]: https://www.rfc-editor.org/rfc/rfc3629.
  /// [RFC 2616]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html
  String get body => _encodingForHeaders(headers).decode(bodyBytes);

  /// Creates a new HTTP response with a string body.
  Response(String body, int statusCode,

http's Response.dart

Here's the examples from https://www.rfc-editor.org/rfc/rfc9110.html (redirected from RFC 2616):

For example, the following media types are equivalent in describing HTML text data encoded in the UTF-8 character encoding scheme, but the first is preferred for consistency (the "charset" parameter value is defined as being case-insensitive in [RFC2046], Section 4.1.2):

  text/html;charset=utf-8
  Text/HTML;Charset="utf-8"
  text/html; charset="utf-8"
  text/html;charset=UTF-8

Now the test works fine.

Clean up with `Provider`?

According to the docs for runWithClient, in Flutter, we can use a Provider instead. This makes the code much cleaner:

await tester.pumpWidget(
  MaterialApp(
    home: Scaffold(
      body: Provider(
        create: (_) => MockClient((request) async {
          MockClient((request) async {
            final content = File('test/airtag.html').readAsStringSync();
            return http.Response(
              content,
              200,
              headers: {'content-type': 'text/html; charset=utf-8'},
            );
          }),
        }),
        child: BubbleWidget(b),
      ),
    ),
  ),
);

Unfortunately, this did not work. I don't know the system well enough to figure out why. But basically, the Widget that was supposed to use Client and render, seemed to be immediately destroyed?... I don't even know if that's possible. I put breakpoints in that Widget's build and it was never called.

So I ended up using runWithClient. Maybe some day I'll figure out how to use Provider.

Who's the gourmet brewmaster from Culinary Class Wars 2?

wafrat — Wed, 17 Dec 2025 02:54:47 GMT

The one who makes soju? https://www.instagram.com/yunjudang/. You're welcome!

Mocking cross-platform plugins like url_launcher

wafrat — Tue, 16 Dec 2025 05:42:25 GMT

Today I wanted to mock url_launcher, but it was not as easy as the docs said.

Here's the code I wanted to test:

Future launchSearch(String word, SearchType searchType) async {
  final url = getSearchUrl(word, searchType);
  Uri uri = Uri.parse(url);
  if (await canLaunchUrl(uri)) {
    await launchUrl(uri);
  } else {
    throw 'Could not launch $url';
  }
}

I wanted to check that it launched the correct URL.

canLaunchUrl and launchUrl use Platform dependent code:

Future canLaunchUrl(Uri url) async {
  return UrlLauncherPlatform.instance.canLaunch(url.toString());
}

...

Future launchUrl(
  Uri url, {
  LaunchMode mode = LaunchMode.platformDefault,
  WebViewConfiguration webViewConfiguration = const WebViewConfiguration(),
  BrowserConfiguration browserConfiguration = const BrowserConfiguration(),
  String? webOnlyWindowName,
}) async {
  if ((mode == LaunchMode.inAppWebView ||
          mode == LaunchMode.inAppBrowserView) &&
      !(url.scheme == 'https' || url.scheme == 'http')) {
    throw ArgumentError.value(url, 'url',
        'To use an in-app web view, you must provide an http(s) URL.');
  }
  return UrlLauncherPlatform.instance.launchUrl(
    url.toString(),
    LaunchOptions(...),
  );
}

url_launcher_uri.dart

And the package lets you set the instance:

abstract class UrlLauncherPlatform extends PlatformInterface {
  /// Constructs a UrlLauncherPlatform.
  UrlLauncherPlatform() : super(token: _token);

  static final Object _token = Object();

  static UrlLauncherPlatform _instance = MethodChannelUrlLauncher();

  /// The default instance of [UrlLauncherPlatform] to use.
  ///
  /// Defaults to [MethodChannelUrlLauncher].
  static UrlLauncherPlatform get instance => _instance;

  /// Platform-specific plugins should set this with their own platform-specific
  /// class that extends [UrlLauncherPlatform] when they register themselves.
  // TODO(amirh): Extract common platform interface logic.
  // https://github.com/flutter/flutter/issues/43368
  static set instance(UrlLauncherPlatform instance) {
    PlatformInterface.verify(instance, _token);
    _instance = instance;
  }
  ...
}

url_launcher_platform_interface's url_launcher_platform.dart

And plugin_platform_interface's code explains how to override it in tests:

  /// Ensures that the platform instance was constructed with a non-`const` token
  /// that matches the provided token and throws [AssertionError] if not.
  ///
  /// This is used to ensure that implementers are using `extends` rather than
  /// `implements`.
  ///
  /// Subclasses of [MockPlatformInterfaceMixin] are assumed to be valid in debug
  /// builds.
  ///
  /// This is implemented as a static method so that it cannot be overridden
  /// with `noSuchMethod`.
  static void verify(PlatformInterface instance, Object token) {
    _verify(instance, token, preventConstObject: true);
  }

plugin_platform_interface.dart

/// A [PlatformInterface] mixin that can be combined with fake or mock objects,
/// such as test's `Fake` or mockito's `Mock`.
///
/// It passes the [PlatformInterface.verify] check even though it isn't
/// using `extends`.
///
/// This class is intended for use in tests only.
///
/// Sample usage (assuming `UrlLauncherPlatform` extends [PlatformInterface]):
///
/// ```dart
/// class UrlLauncherPlatformMock extends Mock
///    with MockPlatformInterfaceMixin
///    implements UrlLauncherPlatform {}
/// ```
@visibleForTesting
abstract mixin class MockPlatformInterfaceMixin implements PlatformInterface {}

plugin_platform_interface.dart

Interesting that plugin_platform_interface shows the sample code for the exact same package I am trying to mock!

So I copy/paste this code, and try it in my tests:

main() {
  testWidgets('Search menu icon', (WidgetTester tester) async {
    // Set up UrlLauncher mocks.
    final urlLauncherPlatformMock = UrlLauncherPlatformMock();
    UrlLauncherPlatform.instance = urlLauncherPlatformMock;
    when(urlLauncherPlatformMock.canLaunch(any))
        .thenAnswer((_) async => Future.value(true));
    ...
  });
}

class UrlLauncherPlatformMock extends Mock
    with MockPlatformInterfaceMixin
    implements UrlLauncherPlatform {}

Unfortunately, any throws a compilation error:

The argument type 'Null' can't be assigned to the parameter type 'String'.

This is because Mockito requires the method to accept nullable parameters for any to work. The problem is, the only way to generate methods that accept nullable parameters is to use Mockito's GenerateNiceMocks automated mock generation feature (https://pub.dev/packages/mockito#lets-create-mocks, https://github.com/dart-lang/mockito/blob/master/NULL_SAFETY_README.md).

The problem is, if I use GenerateNiceMocks, then the generated mock will indeed let me use any to capture parameters, but it won't implement the right mixin, and verify will fail.

The solution is to first generate a mock with nullable parameters using GenerateNiceMocks, then subclass that with the right mixin.

import 'package:flashcards/search_list_tile.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:language_picker/languages.dart';
import 'package:mockito/annotations.dart';
import 'package:mockito/mockito.dart';
import 'package:plugin_platform_interface/plugin_platform_interface.dart';
import 'package:url_launcher_platform_interface/url_launcher_platform_interface.dart';

@GenerateNiceMocks([MockSpec()])
import 'search_test.mocks.dart';

main() {
  testWidgets('Search menu icon', (WidgetTester tester) async {
    // Set up UrlLauncher mocks.
    final urlLauncherPlatformMock = MockUrlLauncherPlatformWithMixin();
    UrlLauncherPlatform.instance = urlLauncherPlatformMock;
    when(urlLauncherPlatformMock.canLaunch(any))
        .thenAnswer((_) async => Future.value(true));

    // Render.
    await tester.pumpWidget(MaterialApp(
        home: Scaffold(
            body: Center(
      child: SearchListTile.getSearchMenuIcon(
          Languages.korean, Languages.english, '콧구멍'),
    ))));
    await tester.pump();

    ...

    // Verify.
    verify(urlLauncherPlatformMock.launchUrl(
        'https://dict.naver.com/search.nhn?query=%EC%BD%A7%EA%B5%AC%EB%A9%8D',
        any));
  });
}

class MockUrlLauncherPlatformWithMixin extends MockUrlLauncherPlatform
    with MockPlatformInterfaceMixin {}

How to fix Null issue when using Mockito's `any` or `captureAny`

wafrat — Thu, 13 Nov 2025 02:24:53 GMT

This morning I was trying to verify an invocation with Mockito in Dart, but somehow it threw an error about Null.

The argument type 'Null' can't be assigned to the parameter type 'Todo'. dart(argument_type_not_assignable)

A few searches proposed unsatisfactory workarounds, basically saying we should change our API to accept a nullable parameter:

The official Mockito doc about null safety isn't particularly useful either: https://github.com/dart-lang/mockito/blob/master/NULL_SAFETY_README.md#argument-matchers

Eventually, I found this:

What they mean is that you may implement a Mock that supports nullable types, without changing your actual API. What's more, @GenerateNiceMocks already does that for us.

So in my test, instead of defining my mockTodoProvider as a TodoProvider, I defined it as a MockTodoProvider, and now my test compiles!

Before:

main() {
  late TodoProvider todoProvider;

  setUp(() async {
    todoProvider = MockTodoProvider();
  });
  
  testWidgets(...);
}

After:

main() {
  late MockTodoProvider todoProvider;

  setUp(() async {
    todoProvider = MockTodoProvider();
  });
  
  testWidgets(...);
}

Now my test compiles and runs fine:

testWidgets('delete todo', (WidgetTester tester) async {
  await tester.pumpWidget(MaterialApp(...));
  ...
  // Check the box.
  await tester.tap(find.byType(Checkbox));
  // Verify that update() has been called.
  final verificationResult = verify(p.update(captureAny));
  // Check that the passed Todo has been marked as done.
  final capturedTodo = verificationResult.captured.first;
  expect(capturedTodo.done, isTrue);
});

Related docs:

How to process a paste command but still let TextField handle it?

wafrat — Sat, 20 Sep 2025 00:15:11 GMT

It took me hours to figure out. I was not able to find sample code, and ChatGPT and Gemini kept hallucinating answers...

Basic implementation. TextField stops responding to paste events

Here's the usual way of handling a shortkey:

Shortcuts(
  shortcuts: const {
    SingleActivator(
      LogicalKeyboardKey.keyV,
      // Command key on Mac.
      meta: true,
    ): PasteIntent(),
  },
  child: Actions(
      actions: {
        PasteIntent:
            CallbackAction(onInvoke: (intent) {
          // Do something
        })
      },
      child: TextField(...)
      ))


// Later define our custom Intent
class PasteIntent {}

And it will indeed execute your code when you press Command+V. However, this will prevent the TextField from ever processing the command.

Attempting to pass through the event to TextField

DoNothingAndStopPropagationIntent

I found this DoNothingAndStopPropagationIntent that supposedly "disable[s] a keyboard shortcut defined by a widget higher in the widget hierarchy", so I thought I could create a Shortcuts, handle the event, then add another Shortcuts using that StopPropagationIntent that wraps the TextField. It did not work.

Reusing PasteTextIntent, Actions.maybeFind

Then I tried to reuse what I assumed was the original PasteIntent used by Flutter widgets themselves. Instead of mapping Command+V to my custom PasteIntent, I used PasteTextIntent. Then in my callback, I tried to find other actions in the Context based on https://docs.flutter.dev/ui/interactivity/actions-and-shortcuts#invoking-actions. Something like this:

Action? paste = Actions.maybeFind(
  context,
);
paste?.invoke(intent);

But it did not find TextField's Action for PasteTextIntent.

consumesKey: false?

Another thing I tried was to create a real Action instead of a CallbackAction, and implement Action's consumesKey.

consumesKey method - Action class - widgets library - Dart API

API docs for the consumesKey method from the Action class, for the Dart programming language.

Dart API

By returning false, I hoped that Shortcut would think my Action didn't consume the event, and propagate it down to the TextField. This did not work either.

The solution: Action.overridable

Eventually, I stumbled upon Action.overridable and that's how I fixed my issue. Action.overridable makes someone allow someone else to override their Action. The beauty of it is that if you override that Action, you also get a reference to the default action.

Action.overridable constructor - Action - widgets library - Dart API

API docs for the Action.overridable constructor from Class Action from the widgets library, for the Dart programming language.

Dart API

The issue is, it only works if the creator of the original Action allows their Action to be overridable. Does TextField allow it?

DefaultTextEditingShortcuts class - widgets library - Dart API

API docs for the DefaultTextEditingShortcuts class from the widgets library, for the Dart programming language.

Dart API

flutter/packages/flutter/lib/src/widgets/editable_text.dart at 7ade3f344755eb86b20aae39610a5758b7e510d8 · flutter/flutter

Flutter makes it easy and fast to build beautiful apps for mobile and beyond - flutter/flutter

GitHubflutter

flutter/packages/flutter/lib/src/widgets/default_text_editing_shortcuts.dart at 7ade3f344755eb86b20aae39610a5758b7e510d8 · flutter/flutter

Flutter makes it easy and fast to build beautiful apps for mobile and beyond - flutter/flutter

GitHubflutter

And the answer is YES! So here's my final solution. This will execute my code to handle Command+V but also let TextField handle it:

Shortcuts(
  shortcuts: const {
    SingleActivator(
      LogicalKeyboardKey.keyV,
      // command on Mac.
      meta: true,
    ): PasteTextIntent(SelectionChangedCause.keyboard),
  },
  child: Actions(
      actions: >{
        // Override TextField's handler to also support images.
        PasteTextIntent:
            PasteScreenshotAction(onFilePasted: (xfile) {
          filesPicked.add([xfile]);
        })
      },
      child: TextField(...)
  ))
...

class PasteScreenshotAction extends Action {
  PasteScreenshotAction({required this.onFilePasted});

  final void Function(XFile xfile) onFilePasted;

  @override
  Object? invoke(covariant PasteTextIntent intent) async {
    // Let TextField process the paste.
    callingAction?.invoke(intent);

    // And also handle images from the clipboard.
    ..
  }
}

Mocking time in UI tests in Flutter

wafrat — Tue, 16 Sep 2025 01:24:30 GMT

When working with tests that test logic related to time, it is necessary to mock the time, especially if that time is being rendered in screenshot tests.

My code from the stone age would take an optional DateTime? now parameter to mock it. Then in the method, I would run now ?? DateTime.now() to determine the current time. But the cleaner way is to use Clock.

clock | Dart package

A fakeable wrapper for dart:core clock APIs.

Dart packages

So that's what I did. Before:

testWidgets('share text', (WidgetTester tester) async {
  initializeTimeZones();
  await initializeDateFormatting(AppLocale);
  await loadFont();

  ...
  await tester.pumpWidget(
    MyApp(now: todayAtNoon),
  );
  await tester.pumpAndSettle();

  await expectLater(
    find.byType(MaterialApp),
    matchesGoldenFile(
      'goldens/app/iosShareText1.png',
    ),
  );

  await tester.tap(find.byIcon(Icons.send).first);
  await tester.pumpAndSettle();
  // TODO: fix clock issues to show the message having been sent.
  await expectLater(
    find.byType(MaterialApp),
    matchesGoldenFile(
      'goldens/app/iosShareText2Sent.png',
    ),
  );
});

testWidgets('share image', (WidgetTester tester) async {
  ...
});

After:

withClock(Clock.fixed(todayAtNoon.add(Duration(hours: 3))), () async {
  testWidgets('share text', (WidgetTester tester) async {
    initializeTimeZones();
    await initializeDateFormatting(AppLocale);
    await loadFont();

    ...
    await tester.pumpWidget(
      MyApp(),
    );
    await tester.pumpAndSettle();

    await expectLater(
      find.byType(MaterialApp),
      matchesGoldenFile(
        'goldens/app/iosShareText1.png',
      ),
    );

    await tester.tap(find.byIcon(Icons.send).first);
    await tester.pumpAndSettle();
    // TODO: fix clock issues to show the message having been sent.
    await expectLater(
      find.byType(MaterialApp),
      matchesGoldenFile(
        'goldens/app/iosShareText2Sent.png',
      ),
    );
  });

  testWidgets('share image', (WidgetTester tester) async {
    ...
  });
});

I wrapped all of my tests in a withClock instead of using withClock in each testWidgets to not have to write the same withClock boilerplate. However, in my screenshot, the time was still not the mocked time. It was the actual current time!

So I added this code inside the withClock and inside the testWidgets to check the value of clock:

print(clock.now());

And indeed, as soon as in goes inside testWidgets, clock gets reset back.

So I had to invert how I set up time and add withClock inside each testWidgets:

testWidgets('share text', (WidgetTester tester) async {
  withClock(Clock.fixed(todayAtNoon.add(Duration(hours: 3))), () async {
    initializeTimeZones();
    await initializeDateFormatting(AppLocale);
    await loadFont();

    ...
    await tester.pumpWidget(
      MyApp(),
    );
    await tester.pumpAndSettle();

    await expectLater(
      find.byType(MaterialApp),
      matchesGoldenFile(
        'goldens/app/iosShareText1.png',
      ),
    );

    await tester.tap(find.byIcon(Icons.send).first);
    await tester.pumpAndSettle();
    // TODO: fix clock issues to show the message having been sent.
    await expectLater(
      find.byType(MaterialApp),
      matchesGoldenFile(
        'goldens/app/iosShareText2Sent.png',
      ),
    );
  });

  testWidgets('share image', (WidgetTester tester) async {
    withClock(Clock.fixed(todayAtNoon.add(Duration(hours: 3))), () async {
      ...
    });
  });
});

Now the screenshot shows up correctly with the mocked time, but I get this error:

══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
The following StateError was thrown running a test (but after the test had completed):
Bad state: No element

When the exception was thrown, this was the stack:
#0      Iterable.first (dart:core/iterable.dart:663:7)
#1      _FirstFinderMixin.filter (package:flutter_test/src/finders.dart:1332:28)
#3      Iterable.isEmpty (dart:core/iterable.dart:560:33)
#4      WidgetController._getElementPoint (package:flutter_test/src/controller.dart:2008:18)
#5      WidgetController.getCenter (package:flutter_test/src/controller.dart:1861:12)
#6      WidgetController.tap (package:flutter_test/src/controller.dart:1041:7)
#7      main... (file:///[project_path]/test/app_test.dart:216:22)

(elided one frame from dart:async-patch)
════════════════════════════════════════════════════════════════════════════════════════════════════

How can it not find the Send icon button? I can see it fine in the screenshot.

Here's what Google AI Overview has to say about clock:

Really? clock is automatically mocked and set to Jan 1, 2015? So I try it:

void main() {
  testWidgets('signs in', (WidgetTester tester) async {
    print(clock.now());
    ...

Nope, it shows me the current time.

After some more research, I find this post: https://docs.flutter.dev/release/breaking-changes/test-widgets-flutter-binding-clock. It mentions tester.binding.clock. Let's try it:

void main() {
  testWidgets('signs in', (WidgetTester tester) async {
    print(clock.now());
    print(tester.binding.clock.now());

And it outputs:

00:01 +0: signs in
2025-09-16 09:55:26.754504
2015-01-01 00:00:00.000Z

WOW!

What if I start a zone with withClock that uses the same Clock? Then the test and the logic's Clock would match, and pump would advance the same time...

void main() {
  testWidgets('signs in', (WidgetTester tester) async {
    withClock(tester.binding.clock, () async {
      print(clock.now());
      print(tester.binding.clock.now());

      initializeTimeZones();
      await initializeDateFormatting(AppLocale);
      await loadFont();
      ...
      await tester.pumpWidget(
        MyApp(),
      );

      expect(find.text('Sign in'), findsOneWidget);

Nope, it still cannot find the button.

So I searched some more, and stumbled upon this blog post: https://retired.re-ynd.com/friends-roster-testing-in-flutter/.

He did the same: testWidgets inside of which he calls withClock, then renders his UI, and finds the element correctly. How come?

The only difference I can find is he awaits withClock. Let's try that.

void main() {
  testWidgets('signs in', (WidgetTester tester) async {
    await withClock(tester.binding.clock, () async {
      initializeTimeZones();
      await initializeDateFormatting(AppLocale);
      await loadFont();
      ...
      await tester.pumpWidget(
        MyApp(),
      );

      expect(find.text('Connexion'), findsOneWidget);
      expect(find.text('hello'), findsNothing);

      await expectLater(
        find.byType(MaterialApp),
        matchesGoldenFile(
          'goldens/app/signedOut.png',
        ),
      );
      ...

Mmh... It actually works!! Haha. Somehow I expected withClock to be synchronous, but it actually returns the result of the callback, which is a Future since I am using async.

Using Firebase Storage on Flutter Web

wafrat — Mon, 08 Sep 2025 03:30:53 GMT

My app was working fine on Android, iOS and MacOS, but it wouldn't display images stored in Firebase Storage. It would fail with the dreaded CORS error.

I need to somehow whitelist localhost:5000 for Firebase Storage. It is well documented at https://firebase.google.com/docs/storage/web/download-files#cors_configuration. It's just extra work.

First I needed to install gsutil ( https://cloud.google.com/storage/docs/gsutil_install) and sign in with gcloud init.

Next, I create my cors.json file.

[
  {
    "origin": ["localhost:5000", "[production domain]"],
    "method": ["GET"],
    "maxAgeSeconds": 3600
  }
]

Finally I apply the settings:

% gsutil cors set cors.json gs://[project-id]
Setting CORS on gs://[project-id]/...
NotFoundException: 404 The specified bucket does not exist.

% gsutil cors set cors.json gs://[project-id].appspot.com
Setting CORS on gs://[project-id].appspot.com/...

But I still got the same error.

So instead I tried to temporarily whitelist everything: "origin": "*". And it worked: my app displayed the image from Firebase Storage! So it looks like it is not enough to specify the domain, I need to specify whether it's http or https:

[
  {
    "origin": ["http://localhost:5000", "https://[production domain]"],
    "method": ["GET"],
    "maxAgeSeconds": 3600
  }
]

And indeed, it worked with this more restrictive setting.

Google Sign-in for Flutter Web

wafrat — Mon, 08 Sep 2025 02:54:08 GMT

My Flutter app was running fine for Web until I migrated google_sign_in from 6 to 7. Now signing-in fails with this error: Sign in failed: UnimplementedError: authenticate is not supported on the web. Instead, use renderButton to create a sign-in widget. Let's fix it.

Up until google_sign_in 6, it seemed like I could use the same code to sign in on iOS and Web. But from version 7, authentication on Web is different.

google_sign_in | Flutter package

Flutter plugin for Google Sign-In, a secure authentication system for signing in with a Google account.

Dart packages

google_sign_in_web | Flutter package

Flutter plugin for Google Sign-In, a secure authentication system for signing in with a Google account on Android, iOS and Web.

Dart packages

On the web, instead of providing custom UI that calls authenticate, you should display the Widget returned by renderButton (from web_only.dart), and listen to authenticationEvents to know when the user has signed in.

Adding the button

renderButton function - web_only library - Dart API

API docs for the renderButton function from the web_only library, for the Dart programming language.

Dart API

I changed my code to render that special button on Web:

Before:

ElevatedButton(
    child: Text('Sign in'),
    onPressed: () {
      _handleSignIn(widget.auth, widget.googleSignIn);
    })

After:

!kIsWeb
    ? ElevatedButton(
        child: Text('Sign in'),
        onPressed: () {
          _handleSignIn(widget.auth, widget.googleSignIn);
        })
    : renderButton()

Adding the dependency

However, VSC couldn't find the renderButton. https://pub.dev/packages/google_sign_in_web has the explanation why:

This package is endorsed, which means you can simply use google_sign_in normally. This package will be automatically included in your app when you do, so you do not need to add it to your pubspec.yaml. However, if you import this package to use any of its APIs directly, you should add it to your pubspec.yaml as usual. For example, you need to import this package directly if you plan to use the web-only Widget renderButton() method.

So I do need to manually import this package.

init()

After I add the renderButton, I am getting the following error:

Bad state: GoogleSignInPlugin::init() or GoogleSignInPlugin::initWithParams() must be called before any other method in this plugin.

Looking back at https://pub.dev/packages/google_sign_in#usage, I have all the information I need to initialize it in code:

unawaited(_googleSignIn.initialize(
        clientId:
            '....apps.googleusercontent.com'));

Back in version 6, I had two choices to initialize GoogleSignIn. I could either pass the client id in code, or add a tag. I guess the meta tag way does not work anymore.

Running with a fixed port

If I attempt to run in Chrome using VSC's built-in Play button, the web app runs on a random port every time. Then Google Sign-In will throw an Access blocked: Authorization Error, Error 400: origin_mismatch.

So I need to run the exact port that I whitelisted on the Cloud Console:

flutter run -d chrome --web-port 5000

After setting it all up, Google Sign-In works on Web again! But wait a second...

Restoring compilation for iOS

Adding a dependency to google_sign_in_web actually broke compilation on other platforms like iOS. When I try to run the app on iOS, I get those errors:

 ../../.pub-cache/hosted/pub.dev/web-1.1.1/lib/src/dom/webrtc.dart:1067:40: Error: 'JSObject' isn't a type.
    extension type RTCRtpTransceiverInit._(JSObject _) implements JSObject {
                                           ^^^^^^^^
    ../../.pub-cache/hosted/pub.dev/web-1.1.1/lib/src/dom/webrtc.dart:1070:5: Error: 'JSArray' isn't a type.
        JSArray streams,
        ^^^^^^^
    ../../.pub-cache/hosted/pub.dev/web-1.1.1/lib/src/dom/webrtc.dart:1071:5: Error: 'JSArray' isn't a type.
        JSArray sendEncodings,
        ^^^^^^^
...

    ../../.pub-cache/hosted/pub.dev/google_identity_services_web-0.3.3+1/lib/src/js_interop/google_accounts_oauth2.dart:79:51: Error: The getter 'toJS' isn't defined for the
    type 'void Function(TokenRevocationResponse)'.
    Try correcting the name to the name of an existing getter, or defining a getter or field named 'toJS'.
        return _revokeWithDone(accessToken.toJS, done.toJS);
                                                      ^^^^
    ../../.pub-cache/hosted/pub.dev/google_identity_services_web-0.3.3+1/lib/src/js_interop/google_accounts_oauth2.dart:83:25: Error: 'JSString' isn't a type.
      external void _revoke(JSString accessToken);
                            ^^^^^^^^
    ../../.pub-cache/hosted/pub.dev/google_identity_services_web-0.3.3+1/lib/src/js_interop/google_accounts_oauth2.dart:85:33: Error: 'JSString' isn't a type.
      external void _revokeWithDone(JSString accessToken, JSFunction done);
                                    ^^^^^^^^

Luckily Gemini has a good way to isolate the code.

import 'package:flutter/material.dart';
import 'package:google_sign_in_web/web_only.dart';

class SignInButton extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return renderButton();
  }
}

sign_in_button_web.dart

import 'package:flutter/material.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:provider/provider.dart';

class SignInButton extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final googleSignIn = context.read();

    return ElevatedButton(
        child: Text('Sign in'),
        onPressed: () {
          googleSignIn.authenticate();
        });
  }
}

sign_in_button_not_web.dart

// Default export for mobile/desktop
export 'sign_in_button_not_web.dart'
    // Conditional export for web
    if (dart.library.js_interop) 'sign_in_button_web.dart';

sign_in_button.dart

import 'package:elysium/sign_in_button.dart';

Provider(
    create: (context) => widget.googleSignIn,
    child: SignInButton())

Usage

And indeed, it compiled fine:

Running Xcode build...                                                  
Xcode build done.                                           40.6s
✓ Built build/ios/iphoneos/Runner.app (50.1MB)

Conditional initialize

When I click on Sign in, I now get an error about not supporting the right URL. That's because I initialized GoogleSignIn with the key used for Web, whereas I configured my iOS app to use other keys.

Before:

unawaited(_googleSignIn.initialize(
        clientId:
            '[...].apps.googleusercontent.com'));

Uses the Web key by default

After:

unawaited(_googleSignIn.initialize(
    clientId: kIsWeb
        ? '[...].apps.googleusercontent.com'
        : null));

Only uses the Web key on Web

Flutter for MacOS

wafrat — Mon, 08 Sep 2025 01:15:39 GMT

My first case study for building apps for MacOS was to use Apple's built-in capability of running iOS apps natively on Macs with Apple Silicon (see https://www.wafrat.com/flutter-ios-app-for-macos/). This time, since I want to use features that may not be available on iOS such as a proper File Picker, I want to make compile my Flutter app specifically for MacOS.

Starting from https://pub.dev/packages/google_sign_in#platform-integration, I am told to refer to the integration steps for iOS and MacOS: https://pub.dev/packages/google_sign_in_ios#macos-integration.

So I set up [my_project]/macos/Runner/Info.plist the same was as I set up [my_project]/ios/Runner/Info.plist. I also add this additional key-value as instructed:

keychain-access-groups

    $(AppIdentifierPrefix)com.google.GIDSignIn

When I run the app and try to sign in, I can enter my credentials and accept what permissions I grant the app upon signing-in, but as soon as I click "Next", the Google sign-in page disappears, but my app does not receive any Google credential. There is also no error in the console.

Printing out errors

In the documentation, they show how listen for errors. However I could not find this API in google_sign_in 6. So I had to migrate to the 7, which is the latest major version.

  googleSignIn.authenticationEvents.listen((e) {
    print('event');
    print(e);
  }).onError((e) {
    print('error');
    print(e);
  });

Now I can remove the configuration and add them back one by one to make sure they are truly necessary.

GIDClientID

This time, upon clicking the Sign-In button, the Google Sign-In page does not pop up. Instead I get this message.

flutter: Sign in failed: PlatformException(google_sign_in, No active configuration. Make sure GIDClientID is set in Info.plist., NSInvalidArgumentException, null)

Good, let's add that back to [my_project]/macos/Runner/Info.plist.

CFBundleURLSchemes

flutter: Sign in failed: PlatformException(google_sign_in, Your app is missing support for the following URL schemes: com.googleusercontent.apps.[redacted], NSInvalidArgumentException, null)

After adding this step, the Google Sign-In page does pop up correctly and lets me enter my credentials. Upon clicking "Continue" to finish the sign-in process, my app throws this error:

flutter: Sign in failed: PlatformException(org.openid.appauth.general: -5, Connection error making token request to 'https://oauth2.googleapis.com/token': The operation couldn’t be completed. Operation not permitted., {NSLocalizedDescription: Connection error making token request to 'https://oauth2.googleapis.com/token': The operation couldn’t be completed. Operation not permitted., NSUnderlyingError: {code: 1, domain: NSPOSIXErrorDomain, localizedDescription: The operation couldn’t be completed. Operation not permitted, userInfo: {_NSURLErrorFailingURLSessionTaskErrorKey: LocalDataTask .<1>, _kCFStreamErrorDomainKey: 1, _kCFStreamErrorCodeKey: 1, _NSURLErrorRelatedURLSessionTaskErrorKey: [LocalDataTask .<1>], _NSURLErrorNWPathKey: [Unsupported type: NWConcrete_nw_path]}}}, null)

Outgoing Network Connections (not documented!)

This is actually not documented in the google_sign_in documentation on pub.dev. When I asked Gemini about it, it revealed that I should enable outgoing network connections in XCode.

Gotta check that box

Incoming Connections?

When I wrote this post, I noticed that Incoming Connections (Server) was already checked, and I was not sure why. So I disabled it, and now I know:

✓ Built build/macos/Build/Products/Debug/elysium_mobile_client.app
2025-09-08 09:42:29.794 [app_name] Running with merged UI and platform thread. Experimental.
flutter: Could not start Dart VM service HTTP server:
SocketException: Failed to create server socket (OS Error: Operation not permitted, errno = 1), address = 127.0.0.1, port = 0
#0      _NativeSocket.bind (dart:io-patch/socket_patch.dart:1220:7)

#1      _RawServerSocket.bind. (dart:io-patch/socket_patch.dart:2166:12)

#2      _ServerSocket.bind. (dart:io-patch/socket_patch.dart:2521:12)

#3      _HttpServer.bind. (dart:_http/http_impl.dart:3506:24)

#4      Server.startup.startServer (dart:vmservice_io/vmservice_server.dart:317:23)

#5      Server.startup (dart:vmservice_io/vmservice_server.dart:339:11)

#6      _toggleWebServer (dart:vmservice_io:229:5)


2025-09-08 09:42:30.134 [app_name] The operation couldn’t be completed. (OSStatus error 13.)
```

Flutter needs to connect to it to provide debugging information.

keychain-access-groups entitlement

After restoring the Incoming Connections Capability, I am getting the next error:

flutter: Sign in failed: GoogleSignInException(code GoogleSignInExceptionCode.providerConfigurationError, keychain error, {NSLocalizedDescription: keychain error})

This one looks familiar. It is the one that https://pub.dev/packages/google_sign_in_ios#macos-integration mentioned:

However, the error persisted even after adding this key/value to Info.plist. So I read about it a bit more on https://docs.flutter.dev/platform-integration/macos/building#entitlements-and-the-app-sandbox. It turns out entitlements are written in another file: macos/Runner/DebugProfile.entitlements.

Gemini suggested to add the Capability using the XCode UI itself. That would have prevented my mistake.

Weird XCode compilation setting

After adding the Keychain Sharing Capability, my app wouldn't launch anymore. When I checked in XCode, I saw this new error:

I had to Enable Development Signing for my app to run again.

Google People API (not documented!)

At some point in the process, another error I got from google_sign_in was that I should enable the Google People API at https://console.cloud.google.com/apis/library/people.googleapis.com. So I did, but what is puzzling is, I have never had this error on iOS.

Success

After setting all of this up, my Flutter app compile for MacOS and I can successfully sign into my Google Account!

Publishing to TestFlight

Reference docs:

+ xcodebuild -exportArchive -exportOptionsPlist ...
2025-09-08 14:30:08.535 xcodebuild[7313:3471315] [MT] IDEDistribution: Command line name "app-store" is deprecated. Use "app-store-connect" instead.
error: exportArchive No signing certificate "Mac Installer Distribution" found

error: exportArchive No profiles for '[package name]' were found

** EXPORT FAILED **
[14:30:32]: Exit status: 70

Validating

LSApplicationCategoryType | Apple Developer Documentation

The category that best describes your app for the App Store.

Apple Developer Documentation

The value of the CFBundleDocumentTypes key in the Info.plist must be an array of dictionaries, with each dictionary containing at least the CFBundleTypeName key. (ID: 76cfdd64-fce6-4823-88c3-5791ae6d9895)

That's becaeuse I accidentally added an empty one by clicking around the XCode UI earlier. Removing this:

	CFBundleDocumentTypes

Publishing to TestFlight

After the few tweaks to Info.plist, XCode successfully validates. So I try to Distribute to TestFlight, and that steps successfully completes too. As soon as that step completes, I head over App Store Connect, and I do see that a build for macOS has appeared in my app's TestFlight tab!

At first the tab is gray, but after a few minutes, the UI renders and shows that its status is Processing.

Fastlane

Now that I've successfully distributed a macOS built to TestFlight, I am hoping that the Mac Installer Distribution error I encountered with Fastlane has been resolved. Let's try to publish another build again with Fastlane.

I increment my app version in pubspec.yaml, then try again.

And sure enough, it worked!

[15:47:48]: Successfully exported and compressed dSYM file
[15:47:48]: Successfully exported the .app file:
[15:47:48]: ./[app name].app
[15:47:48]: Generated plist file with the following values:
[15:47:48]: ▸ -----------------------------------------
[15:47:48]: ▸ {
[15:47:48]: ▸   "method": "app-store"
[15:47:48]: ▸ }
[15:47:48]: ▸ -----------------------------------------
...
[15:49:41]: Successfully exported and signed the pkg file:
[15:49:41]: ----------------------------------
[15:49:41]: --- Step: upload_to_testflight ---
[15:49:41]: ----------------------------------
[15:49:41]: Login to App Store Connect ([account name])
[15:49:43]: Login successful
[15:49:44]: Ready to upload new build to TestFlight (App: [app id])...
[15:49:44]: Fetching password for transporter from environment variable named `FASTLANE_APPLE_APPLICATION_SPECIFIC_PASSWORD`
[15:49:45]: Going to upload updated app to App Store Connect
[15:49:45]: This might take a few minutes. Please don't interrupt the script.
[15:52:53]: ------------------------------------------------------------------------------------------------------------------
[15:52:53]: --- Successfully uploaded package to App Store Connect. It might take a few minutes until it's visible online. ---
[15:52:53]: ------------------------------------------------------------------------------------------------------------------
[15:52:53]: Successfully uploaded the new binary to App Store Connect

[15:52:55]: Waiting for processing on... app_id: [...], app_version: 0.9.54, build_version: 54, platform: MAC_OS
[15:52:55]: Read more information on why this build isn't showing up yet - https://github.com/fastlane/fastlane/issues/14997
[15:52:55]: Waiting for the build to show up in the build list - this may take a few minutes (check your email for processing issues if this continues)
[15:53:25]: Waiting for the build to show up in the build list - this may take a few minutes (check your email for processing issues if this continues)
[15:53:55]: Waiting for the build to show up in the build list - this may take a few minutes (check your email for processing issues if this continues)
[15:54:26]: Waiting for the build to show up in the build list - this may take a few minutes (check your email for processing issues if this continues)
[15:55:02]: Waiting for App Store Connect to finish processing the new build (0.9.54 - 54) for MAC_OS
[15:55:33]: Waiting for App Store Connect to finish processing the new build (0.9.54 - 54) for MAC_OS
[15:56:04]: Waiting for App Store Connect to finish processing the new build (0.9.54 - 54) for MAC_OS
[15:56:35]: Waiting for App Store Connect to finish processing the new build (0.9.54 - 54) for MAC_OS
[15:57:05]: Waiting for App Store Connect to finish processing the new build (0.9.54 - 54) for MAC_OS
[15:57:37]: Waiting for App Store Connect to finish processing the new build (0.9.54 - 54) for MAC_OS
[15:58:07]: Successfully finished processing the build 0.9.54 - 54 for MAC_OS
[15:58:07]: Using App Store Connect's default for notifying external testers (which is true) - set `notify_external_testers` for full control
[15:58:07]: Distributing new build to testers: 0.9.54 - 54
[15:58:08]: Export compliance has been set to 'false'. Need to wait for build to finishing processing again...
[15:58:08]: Set 'ITSAppUsesNonExemptEncryption' in the 'Info.plist' to skip this step and speed up the submission
[15:58:09]: Successfully distributed build to Internal testers 🚀

+-------------------------------------------+
|             fastlane summary              |
+------+----------------------+-------------+
| Step | Action               | Time (in s) |
+------+----------------------+-------------+
| 1    | default_platform     | 0           |
| 2    | build_app            | 675         |
| 3    | upload_to_testflight | 507         |
+------+----------------------+-------------+

[15:58:09]: fastlane.tools just saved you 20 minutes! 🎉

Flutter iOS app for MacOS (Apple Silicon)

wafrat — Mon, 08 Sep 2025 00:15:06 GMT

Up till now I had never bothered to look into MacOS compatibility. Scratch that, I did years ago when Flutter first became compatible with MacOS. However at the time, Google Sign In were not, so I could not have run any of my apps on MacOS anyway. This week I finally got enough time to dive into it.

Automatic support of iOS on MacOS (Apple Silicon)

After I installed TestFlight on my Mac, I was surprised to see that half of my iOS apps could already be installed and run natively on it. How? And why wasn't the one I wanted to run available to run on Mac?

package compatibility

At first I thought it was because it relied on packages that were not marked as being compatible with macos. For exemple https://pub.dev/packages/geocoding.

No MacOS support

But even after migrating away from this package, and making sure all dependencies support MacOS, my app was not available in TestFlight on MacOS.

Could it be that the iOS binary is not compatible with MacOS because of some package I missed? It would be really nice to be able to know without having to blindly compile, send it to TestFlight and cross fingers.

Checking Flutter-side compatibility

I asked Google and apparently there are tools to do it.

After adding pubspec_checker to my dev_dependencies, I ran dart run pubspec_checker ios macos and got this matrix:

So my iOS app should totally be compatible to run on MacOS. And yet it still won't show up as being available to run in TestFlight! Could it be some XCode setting?

XCode

Even after comparing two projects, one that was compatible with MacOS and one that was not, according to TestFlight, I could not see any notable difference in settings.

Enabling compatibility in TestFlight

After reading the official documentation on the subject, my app does not seem to use any feature that is specific only to iOS and wouldn't work on MacOS.

Running your iOS apps in macOS | Apple Developer Documentation

Modernize the iOS apps you choose to run on a Mac with Apple silicon, or opt out of running on a Mac altogether.

Apple Developer Documentation

My app does use the device's GPS location. But apparently, even though Macs do not have a GPS, the API, Core Location, works even without a GPS.

The absence of specific hardware on a Mac doesn’t always require you to opt out. You can disable parts of your app that require device-specific hardware, allowing the user to use the rest of your app. Some technologies might also be capable of operating without specific hardware. For example, Core Location doesn’t require GPS to return location data.

Apparently, one can test an iOS app on Mac Silicon without running it in the Simulator. Neat!

Xcode supports debugging, testing, and profiling your iOS app natively on a Mac with Apple silicon. When you open your iOS project in Xcode 12 or later, you have the option to build your app and run it directly in macOS. This option doesn’t run your app in a Simulator; it runs it as an iOS App on Mac. You can then test whether your app’s features work as expected.

And finally, this is the section that was most relevant to my app: https://developer.apple.com/documentation/apple-silicon/running-your-ios-apps-in-macos#Choose-whether-to-include-your-iOS-app-in-the-Mac-App-Store

the App Store automatically makes compatible iOS apps available to users of a Mac with Apple silicon. However, if you’re planning to ship a macOS version of your app, or if your app doesn’t make sense for a Mac, you can change your app’s availability in App Store Connect.

I went to App Store Connect and compared the TestFlight settings of the app that worked and the one that didn't on MacOS and sure enough, the setting for "Test iPhone and iPad Apps on Apple Silicon Macs" was different! After clicking Enable, the app was immediately made available on MacOS in TestFlight!

Click on `Enable`. Problem solved!

Platform-dependent features

Now that I was able to run the iOS app natively on MacOS, I noticed a few problems. On a regular iOS app, I want an App Title to show what app it is. But on MacOS, the window title already states what the app is, so I don't need an App Title. I also noticed the text was slightly too small on MacOS. I wanted to scale the text.

So I tried to platform-dependent logic using Platform.isMacOS. Unfortunately it did not seem to work. Another Google search reveals that when running an iOS app on MacOS, Platform.isMacOS is false and Platform.isIOS is true.

However there are packages that help you detect if it is an iOS app running on MacOS.

flutter_is_ios_app_on_mac | Flutter package

Check if this is an iOS app executed on a mac

Dart packages

That's cool, but after testing my app some more, I am more aware of some limitations which make me want to actually implement real MacOS support.

Limitations

It would take more than just a few cosmetics to make my app comfortable to use on MacOS.

Image picker

My app can send images and the image picker I used only lets you pick among pictures in the Photos Library. On iOS it works as intended. On MacOS, I'd like to be able to drop any image file onto it and upload that. I'd also like a proper File Picker.

Reverse geocoding in Flutter for MacOS

wafrat — Sun, 07 Sep 2025 22:50:31 GMT

For many years, I have been using https://pub.dev/packages/geocoding successfully, but recently I've had to migrate away from it.

This package is great because it is compatible with Android and iOS, and it uses the device's built-in reverse geocoding feature. Since it's built into the device, I don't need an API key to hit the API.

However, I want to run my app as a MacOS app in MacOS and geocoding does not support it.

Someone filed a ticket to the repository back in 2002 to ask for MacOS support, and someone even proposed a pull request around the same time, but despite the package releasing updates regularly, it has been completely ignored.

Instead I'll use the Geocoding API on Google Cloud.

Enabling the API

Go to the Google Cloud Console, APIs, look for Maps Platform APIs. Then in credentials, you can create some API keys. https://console.cloud.google.com/google/maps-apis/credentials. The API to call looks like this:

https://maps.googleapis.com/maps/api/geocode/json?latlng=40.714224,-73.961452&key=YOUR_API_KEY

Reverse geocoding (address lookup) request and response | Geocoding API | Google for Developers

Google for Developers

googleapis

I thought I could use the googleapis package, which is an official package auto-generated from Google API protobufs.

googleapis | Dart package

Auto-generated client libraries for accessing Google APIs described through the API discovery service.

Dart packages

However, to my surprise, the geocoding API is not in there!

googleapis - Dart API docs

googleapis API docs, for the Dart programming language.

Dart API docs

That means I should either find a non-official package or use the REST API manually.

Non-official package

google_geocoding_api | Dart package

This Package implement Google Geocoding API with default and reverse geosearch

Dart packages

Luckily someone already made a package that uses the REST API. They use dio to make the GET requests. https://github.com/Dimolll/google_geocoding_api/blob/e48620092049eddc558c38c1d78921985fa3829e/lib/src/api/geocoding_api.dart#L79

dio | Dart package

A powerful HTTP networking package,supports Interceptors,Aborting and canceling a request,Custom adapters, Transformers, etc.

Dart packages

I followed the README and it worked perfectly.

Setting up Firebase and Google Sign-In in my old Flutter app for Web

wafrat — Sat, 06 Sep 2025 06:15:06 GMT

I've been running an Flutter app for years on Android and iOS. Recently, I wanted to support Web. It should be as simple as running flutter build web, then using Firebase Hosting to publish it to some domain. It ended up being slightly more complicated than that.

Initial set up

First I was quite pleased that the firebase CLI supports multiple logins.

firebase login:add
Visit this URL on this device to log in:
https://accounts.google.com/o/oauth2/auth?...
Waiting for authentication...
✔  Success! Added account [REDACTED]

then I added the hosting information.

% firebase init hosting

     ######## #### ########  ######## ########     ###     ######  ########
     ##        ##  ##     ## ##       ##     ##  ##   ##  ##       ##
     ######    ##  ########  ######   ########  #########  ######  ######
     ##        ##  ##    ##  ##       ##     ## ##     ##       ## ##
     ##       #### ##     ## ######## ########  ##     ##  ######  ########

You're about to initialize a Firebase project in this directory:

  /[project_path]


=== Account Setup

Which account do you want to use for this project? Choose an account or add a new one now

? Please select an option:

✔  Using account: [REDACTED]

=== Project Setup

First, let's associate this project directory with a Firebase project.
You can create multiple project aliases by running firebase use --add, 
but for now we'll just set up a default project.

? Please select an option: Use an existing project
? Select a default Firebase project for this directory:
i  Using project [PROJECT_NAME]

=== Hosting Setup

Your public directory is the folder (relative to your project directory) that
will contain Hosting assets to be uploaded with firebase deploy. If you
have a build process for your assets, use your build's output directory.

? What do you want to use as your public directory? build/web
? Configure as a single-page app (rewrite all urls to /index.html)? Yes
? Set up automatic builds and deploys with GitHub? No
✔  Wrote build/web/index.html

i  Writing configuration info to firebase.json...
i  Writing project information to .firebaserc...

✔  Firebase initialization complete!

Then I build the app for Web: flutter build web, and finally pushed it to a beta channel. I used this doc as a reference https://firebase.google.com/docs/hosting/test-preview-deploy.

% firebase hosting:channel:deploy beta
✔  hosting:channel: Channel beta has been created on site [PROJECT_NAME].

=== Deploying to '[PROJECT_NAME]'...

i  deploying hosting
i  hosting[PROJECT_NAME]: beginning deploy...
i  hosting[PROJECT_NAME]: found 32 files in build/web
✔  hosting[PROJECT_NAME]: file upload complete
i  hosting[PROJECT_NAME]: finalizing version...
✔  hosting[PROJECT_NAME]: version finalized
i  hosting[PROJECT_NAME]: releasing new version...
✔  hosting[PROJECT_NAME]: release complete

✔  Deploy complete!

Project Console: https://console.firebase.google.com/project/[PROJECT_ID]/overview
Hosting URL: https://[PROJECT_NAME].web.app

    ✔  hosting:channel: Channel URL ([PROJECT_NAME): https://[PROJECT_NAME]--beta-[some hash].web.app [expires 2025-09-13 12:34:03]

Everything worked fine except that when I loaded the page, I got a blank page and this error:

Firebase Web set up

In order to read the error message, I ran the project in VSC in Chrome. And I get:

errors.dart:274 Uncaught (in promise) DartError: Assertion failed: file:///Users/[username]/.pub-cache/hosted/pub.dev/firebase_core_web-3.0.0/lib/src/firebase_core_web.dart:288:11
options != null
"FirebaseOptions cannot be null when creating the default app."
    at Object.throw_ [as throw] (errors.dart:274:3)
    at Object.assertFailed (errors.dart:44:3)
    at firebase_core_web.dart:288:18
    at async_patch.dart:623:19
    at async_patch.dart:648:23
    at async_patch.dart:594:19
    at _RootZone.runUnary (zone.dart:1849:54)
    at

Sure enough, my initialization does not pass FirebaseOptions:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  initializeTimeZones();
  await initializeDateFormatting(AppLocale);
  await Firebase.initializeApp();
  runApp(MyApp());
}

Things must have changed between the time I made the app and the latest version of the library. After following the steps at https://firebase.google.com/docs/flutter/setup?platform=ios#initialize-firebase, I get to generate firebase_options.dart based on my project with all the right keys.

My init code now becomes:

await Firebase.initializeApp(
  options: DefaultFirebaseOptions.currentPlatform,
);

Next!

Uncaught (in promise) DartError: Assertion failed: file:///Users/[username]/.pub-cache/hosted/pub.dev/google_sign_in_web-0.12.4+4/lib/google_sign_in_web.dart:144:9
appClientId != null
"ClientID not set. Either set it on a  tag, or pass clientId when initializing GoogleSignIn"
    at Object.throw_ [as throw] (errors.dart:274:3)
    at Object.assertFailed (errors.dart:44:3)
    at google_sign_in_web.dart:144:20
    at async_patch.dart:623:19
    at async_patch.dart:648:23
    at Object._asyncStartSync (async_patch.dart:542:3)
    at

Where do I find this ClientID? Firebase Console or Google Cloud?...

A quick search says it's indeed in Google Cloud. So I went into the Cloud Console, opened my project, and on the left-hand side navigation bar, I see APIs and Services. Then in that page, I can see:

Identity Toolkit API: The Google Identity Toolkit API lets you use open standards to verify a user's identity.

That's the one. In that page, there's a tab called Credentials and that's where the client ids are.

In my project's web/index.html, I add the tag:

When I try to sign in, I get the following error in the Console:

client:74 [GSI_LOGGER-OAUTH2_CLIENT]: Checking popup closed.
client:74 [GSI_LOGGER-TOKEN_CLIENT]: Handling response. {"access_token":"[REDACTED]","token_type":"Bearer","expires_in":3599,"scope":"email profile https://www.googleapis.com/auth/userinfo.email openid https://www.googleapis.com/auth/userinfo.profile","authuser":"0","prompt":"none"}
...
[GSI_LOGGER-TOKEN_CLIENT]: Trying to set gapi client token.
client:74 [GSI_LOGGER-TOKEN_CLIENT]: The OAuth token was not passed to gapi.client, since the gapi.client library is not loaded in your page.
browser_client.dart:82  GET https://content-people.googleapis.com/v1/people/me?sources=READ_SOURCE_TYPE_PROFILE&personFields=photos%2Cnames%2CemailAddresses 403 (Forbidden)
(anonymous) @ browser_client.dart:82
(anonymous) @ async_patch.dart:623
(anonymous) @ async_patch.dart:648
(anonymous) @ async_patch.dart:594
runUnary @ zone.dart:1849
handleValue @ future_impl.dart:222
handleValueCallback @ future_impl.dart:948
_propagateToListeners @ future_impl.dart:977
[_completeWithValue] @ future_impl.dart:720
(anonymous) @ future_impl.dart:804
_microtaskLoop @ schedule_microtask.dart:40
_startMicrotaskLoop @ schedule_microtask.dart:49
tear @ operations.dart:118
(anonymous) @ async_patch.dart:188
Promise.then
_scheduleImmediateWithPromise @ async_patch.dart:187
_scheduleImmediate @ async_patch.dart:160
_scheduleAsyncCallback @ schedule_microtask.dart:70
_rootScheduleMicrotask @ zone.dart:1623
scheduleMicrotask$ @ schedule_microtask.dart:150
schedule @ stream_impl.dart:645
[_addPending] @ stream_impl.dart:368
[_sendData] @ broadcast_stream_controller.dart:428
add @ broadcast_stream_controller.dart:257
[_onTokenResponse] @ gis_client.dart:183
tear @ operations.dart:118
_callDartFunctionFast1 @ js_allow_interop_patch.dart:224
ret @ js_allow_interop_patch.dart:84
Vt.i @ client:352
(anonymous) @ client:121Understand this error
errors.dart:274 Uncaught (in promise) DartError: ClientException: {
  "error": {
    "code": 403,
    "message": "People API has not been used in project [project id] before or it is disabled. Enable it by visiting https://console.developers.google.com/apis/api/people.googleapis.com/overview?project=[project id] then retry. If you enabled this API recently, wait a few minutes for the action to propagate to our systems and retry.",
    "status": "PERMISSION_DENIED",
    "details": [
      {
        "@type": "type.googleapis.com/google.rpc.ErrorInfo",
        "reason": "SERVICE_DISABLED",
        "domain": "googleapis.com",
        "metadata": {
          "serviceTitle": "People API",
          "containerInfo": "[project id]",
          "activationUrl": "https://console.developers.google.com/apis/api/people.googleapis.com/overview?project=[project id]",
          "service": "people.googleapis.com",
          "consumer": "projects/[project id]"
        }
      },
      {
        "@type": "type.googleapis.com/google.rpc.LocalizedMessage",
        "locale": "en-US",
        "message": "People API has not been used in project [project id] before or it is disabled. Enable it by visiting https://console.developers.google.com/apis/api/people.googleapis.com/overview?project=[project id] then retry. If you enabled this API recently, wait a few minutes for the action to propagate to our systems and retry."
      },
      {
        "@type": "type.googleapis.com/google.rpc.Help",
        "links": [
          {
            "description": "Google developers console API activation",
            "url": "https://console.developers.google.com/apis/api/people.googleapis.com/overview?project=[project id]"
          }
        ]
      }
    ]
  }
}
, uri=https://content-people.googleapis.com/v1/people/me?sources=READ_SOURCE_TYPE_PROFILE&personFields=photos%2Cnames%2CemailAddresses
    at Object.throw_ [as throw] (errors.dart:274:3)
    at people.dart:146:7
    at async_patch.dart:623:19
    at async_patch.dart:648:23
    at async_patch.dart:594:19

Now I'm at the point where it might make sense to refer to the Google Sign-In documentation on pub.dev. I find https://pub.dev/packages/google_sign_in_web#integration.

But it's strange that it asks me to enable the People API, since there was never such an error on Android or iOS. Still, I enable it and try to sign in again. And it works!!

Adding the `Update branch` to GitHub PRs

wafrat — Thu, 31 Jul 2025 02:19:33 GMT

In my repositories, my PRs didn't have the Update branch button. This feature is nice when someone proposes a PR that breaks because of a separate issue. So I can fix that issue separately in a PR, merge it. Finally in the other person's PR, I can click Update branch, Rebase, then Rerun the workflows.

No Update branch option

In order to show the Update branch option, go to the repository's Settings page, then check that box.

Now Update branch shows up.

Scaling down my VMs

wafrat — Thu, 23 Jan 2025 08:48:57 GMT

I've had custom apps running on DigitalOcean VMs for years even though it wasn't the most cost efficient nor clean way to run them.

It's high time I turned them down.

Moving domains from .io to .dev

.io domains now cost $64 per year while .dev and .com domains cost only $12 per year. So I stopped renewing my io domains. Now all my mobile apps that point to them need to be recompiled with the new domain name.

Stop the renewal of the io domains on the registrars.
Set up a new DNS on the .dev domains to point to the same VM.
Go to the VM, regenerate the SSL certificates with Certbot.
Change the domain name in the nginx config. Reload nginx.
Recompile my mobile apps to use the new domain.
Publish an update.

Moving an Apache web client to Firebase hosting

The smallest DigitalOcean VM costs $7 per month to run. The web client I am using is completely static. Hence it could be hosted on Firebase hosting.

However the web client is so old that I am not confident I could recompile it from the code. I also need to check what else was on that VM so that I can back it up before destroying it.

Here's the problem: The VM is 6 years old. At the time, for security reasons, I disabled access through login/password and only allowed login through whitelisted SSH keys. Since then, I've sold my old computers. So now I cannot access that VM on my new Mac. I had to go use the Recovery Console:

Use the Recovery Console if you need to use the recovery ISO or you can't connect to your Droplet with the Droplet Console. To use the recovery console, you must enable password authentication. If necessary, you can reset your root password below.

Recovery Console

So I reset my root password, then accessed the Recovery Console. I went into ~/.ssh/authorized_keys and tried to add a new one. The issue? Copy/paste does not work properly in that Recovery Console!!

Droplet Console

DigitalOcean proposes a second way to SSH into the VM: the Droplet Console. I try running that command.

It fails because I don't have wget installed on my machine. A Google search tells me I should run brew install wget. It fails with this error:

Error: can't modify frozen String: "The bottle needs the Xcode Command Line Tools to be installed at /Library/Developer/CommandLineTools.\nDevelopment tools provided by Xcode.app are not sufficient.\n\nYou can install the Xcode Command Line Tools, if desired, with:\n xcode-select --install\n"

So I run xcode-select --install and it decides to download the Internet.

Then I try again:

% wget -qO- https://repos-droplet.digitalocean.com/install.sh | sudo bash
Password:
Verifying machine compatibility...
bash: line 246: dmidecode: command not found

The DigitalOcean Droplet Agent is only supported on DigitalOcean machines.

I was supposed to run it on the VM itself. Can't read...

Once installed, the option to SSH into it on the browser shows up:

Luckily this browser client works better than the recovery console and I was able to copy/paste my new public key into authorized_keys.

I then SSH into it properly, and back up /var/www.html:

/var/www# tar czf project_name.tar.gz html

Then I copy it into my Mac:

scp root@[VM IP]:/var/www/project_name.tar.gz .

Firebase Hosting

Running this command throws a bunch of errors:

% npm install -g firebase-tools
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: 'firebase-tools@13.29.2',
npm WARN EBADENGINE   required: { node: '>=18.0.0 || >=20.0.0' },
npm WARN EBADENGINE   current: { node: 'v16.17.0', npm: '8.19.3' }
npm WARN EBADENGINE }
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '@google-cloud/cloud-sql-connector@1.6.0',
npm WARN EBADENGINE   required: { node: '>=18' },
npm WARN EBADENGINE   current: { node: 'v16.17.0', npm: '8.19.3' }
npm WARN EBADENGINE }
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: 'marked@13.0.3',
npm WARN EBADENGINE   required: { node: '>= 18' },
npm WARN EBADENGINE   current: { node: 'v16.17.0', npm: '8.19.3' }
npm WARN EBADENGINE }
...

I need to switch to Node 18+:

% nvm use 18
Now using node v18.18.0 (npm v10.1.0)

% npm install -g firebase-tools

added 636 packages in 5s

70 packages are looking for funding
  run `npm fund` for details

The tool is pretty nice.

Once set up, I can deploy the static files:

% firebase deploy       

=== Deploying to 'project_name'...

i  deploying hosting
i  hosting[project_name]: beginning deploy...
i  hosting[project_name]: found 7 files in public
✔  hosting[project_name]: file upload complete
i  hosting[project_name]: finalizing version...
✔  hosting[project_name]: version finalized
i  hosting[project_name]: releasing new version...
✔  hosting[project_name]: release complete

✔  Deploy complete!

Project Console: https://console.firebase.google.com/project/project_name/overview
Hosting URL: https://project_name.web.app

The last step is to set up the domain names correctly. When I click "Add custom domain", Firebase asks me to modify the DNS settings to verify my domain ownership. Once that is done, it shows up in my list of domains where the web app is served, and next to the new domain, it says "Minting certificate".

Nice! Now I won't have to run certbot and generate SSL certificates myself anymore!

Wrong instructions from Firebase

Firebase told me to delete the previous [my_app] A field from [my_domain].dev and set up the CNAME as domain: [my_app].[my_domain].dev and wouldn't pass validation until I did. So after it validated, I waited a good 3 hours for the DNS to change.

After 3 hours, pinging failed. Then I googled how long Squarespace actually updates CNAME fields. I found this: https://forum.squarespace.com/topic/320695-two-days-and-cname-has-not-propagated-anywhere/. They complain it's been two days, to which someone responds that the CNAME field should only be [my_app]. So I added such a field and also verified with ping [my_app].[my_domain].dev.[my_domain].dev and this did indeed return. So like the last person said, Google was wrong. Wow.

wafrat

Using SharedPreferences in tests

Mocking http.Client (updated)

Investigation

runWithClient

content-type

Clean up with Provider?

Who's the gourmet brewmaster from Culinary Class Wars 2?

Mocking cross-platform plugins like url_launcher

How to fix Null issue when using Mockito's `any` or `captureAny`

How to process a paste command but still let TextField handle it?

Basic implementation. TextField stops responding to paste events

Attempting to pass through the event to TextField

DoNothingAndStopPropagationIntent

Reusing PasteTextIntent, Actions.maybeFind

consumesKey: false?

The solution: Action.overridable

Mocking time in UI tests in Flutter

Using Firebase Storage on Flutter Web

Google Sign-in for Flutter Web

Adding the button

Adding the dependency

init()

Running with a fixed port

Restoring compilation for iOS

Conditional initialize

Flutter for MacOS

Google Sign-In

Printing out errors

GIDClientID

CFBundleURLSchemes

Outgoing Network Connections (not documented!)

Incoming Connections?

keychain-access-groups entitlement

Weird XCode compilation setting

Google People API (not documented!)

Success

Publishing to TestFlight

Validating

Publishing to TestFlight

Fastlane

Flutter iOS app for MacOS (Apple Silicon)

Automatic support of iOS on MacOS (Apple Silicon)

package compatibility

Checking Flutter-side compatibility

XCode

Enabling compatibility in TestFlight

Platform-dependent features

Limitations

Image picker

Reverse geocoding in Flutter for MacOS

Enabling the API

googleapis

Non-official package

Setting up Firebase and Google Sign-In in my old Flutter app for Web

Initial set up

Firebase Web set up

Google Sign-In

Adding the `Update branch` to GitHub PRs

Scaling down my VMs

Moving domains from .io to .dev

Moving an Apache web client to Firebase hosting

Recovery Console

Droplet Console

Firebase Hosting

Wrong instructions from Firebase

`runWithClient`

`content-type`

Clean up with `Provider`?