alchemist 0.2.0

A support package that aims to make golden testing in Flutter easier and more streamlined.

example/example.md

Alchemist Example

Recommended Setup Guide

For a more detailed explanation on how Betterment uses Alchemist, read the included Recommended Setup Guide.

Basic usage

In your project's test/ directory, add a file for your widget's tests. Then, write and run golden tests by using the goldenTest function.

We recommend putting all golden tests related to the same component into a test group.

Every goldenTest commonly contains a group of scenarios related to each other (for example, all scenarios that test the same constructor or widget in a particular context).

This example shows a basic golden test for ListTiles that makes use of some of the more advanced features of the goldenTest API to control the output of the test.

import 'package:alchemist/alchemist.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  group('ListTile Golden Tests', () {
    goldenTest(
      'renders correctly',
      fileName: 'list_tile',
      constraints: const BoxConstraints(maxWidth: 600),
      widget: GoldenTestGroup(
        columnWidthBuilder: (_) => const FlexColumnWidth(),
        children: [
          GoldenTestScenario(
            name: 'with title',
            child: ListTile(
              title: Text('ListTile.title'),
            ),
          ),
          GoldenTestScenario(
            name: 'with title and subtitle',
            child: ListTile(
              title: Text('ListTile.title'),
              subtitle: Text('ListTile.subtitle'),
            ),
          ),
          GoldenTestScenario(
            name: 'with trailing icon',
            child: ListTile(
              title: Text('ListTile.title'),
              trailing: Icon(Icons.chevron_right_rounded),
            ),
          ),
        ],
      ),
    );
  });
}

Then, simply run Flutter test and pass the --update-goldens flag to generate the golden files.

flutter test --update-goldens