run_with_network_images 0.0.1

Helper for providing mocked Image.network response in Flutter widget tests.

run_with_network_images

A helper for providing mocked response to Image.network in Flutter widget tests.

Introduction

When you test the app that includes Image.network, you get the 400 response.

Because, Image.network uses the HttpClient of dart:io, and the HttpClient of dart:io always returns the 400response in the Flutter widget test.

To fix this issue, you should override the HttpClient to return the mock image instead of the 400 response.

This package overrides it to return the mock image instead of you.

Installing

You can install this package by executing the following command.

flutter pub add --dev run_with_network_images

Or, open the pubspec.yaml file and add the run_with_network_images package to dev_dependencies as follows.

...
dev_dependencies:
  run_with_network_images: [version]
...

Example

You can use the runWithNetworkImages function to fix the 400 response issue of the Image.network. A full test example could look like the following.

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:run_with_network_images/src/run_with_network_images.dart';

void main() {
  testWidgets('Network image is rendered in widget test', (
    WidgetTester tester,
  ) async {
    await runWithNetworkImages(() async {
      await tester.pumpWidget(
        MaterialApp(
          home: Image.network(
            'https://dev-yakuza.posstree.com/assets/images/yakuza.jpg',
          ),
        ),
      );

      final image = tester.widget<Image>(find.byType(Image));
      expect(
        (image.image as NetworkImage).url,
        'https://dev-yakuza.posstree.com/assets/images/yakuza.jpg',
      );
    });
  });
}

You can just wrap the test code with await runWithNetworkImages(() async {}); to fix the issue.

Contributing

If you want to contribute to this package, please see CONTRIBUTING.