flutter_abtest

A Flutter package for implementing UI A/B testing in your Flutter applications. This library allows you to display different UI variations with specified probabilities, making it easy to conduct A/B tests for user interface elements.

Features

• Simple A/B Testing: Easily implement A/B tests with multiple UI variations
• Probability-based Selection: Define custom probabilities for each UI variation
• Flexible Widget Creation: Support both direct widgets and widget builders
• Error Handling: Comprehensive error handling for invalid configurations
• Lightweight: Minimal dependencies, only requires Flutter SDK

Getting started

Installation

Add flutter_abtest to your pubspec.yaml file:

dependencies:
  flutter_abtest: ^0.0.1

Then run:

flutter pub get

Import

import 'package:flutter_abtest/flutter_abtest.dart';

Usage

Basic Usage

The package provides a simple way to implement A/B testing with multiple UI variations. Here's how to use it:

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('A/B Test Example')),
      body: Center(
        child: ABTestManager.testUI([
          // UI A - 50% probability
          ABTestUnit.widget(
            probability: 0.5,
            widget: Container(
              color: Colors.blue,
              child: Text('UI Variation A'),
            ),
          ),
          // UI B - 50% probability
          ABTestUnit.widget(
            probability: 0.5,
            widget: Container(
              color: Colors.red,
              child: Text('UI Variation B'),
            ),
          ),
        ]),
      ),
    );
  }
}

Using Widget Builders

For more complex widgets or when you need dynamic content, use widget builders:

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('A/B Test with Builders')),
      body: Center(
        child: ABTestManager.testUI([
          // UI A - 30% probability
          ABTestUnit.builder(
            probability: 0.3,
            widgetBuilder: () => Container(
              color: Colors.green,
              child: Text('UI Variation A (30%)'),
            ),
          ),
          // UI B - 40% probability
          ABTestUnit.builder(
            probability: 0.4,
            widgetBuilder: () => Container(
              color: Colors.orange,
              child: Text('UI Variation B (40%)'),
            ),
          ),
          // UI C - 30% probability
          ABTestUnit.builder(
            probability: 0.3,
            widgetBuilder: () => Container(
              color: Colors.purple,
              child: Text('UI Variation C (30%)'),
            ),
          ),
        ]),
      ),
    );
  }
}

Advanced Example with Multiple Variations

class AdvancedABTestPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Advanced A/B Test')),
      body: Column(
        children: [
          // Header variation
          ABTestManager.testUI([
            ABTestUnit.widget(
              probability: 0.6,
              widget: Text(
                'Welcome to our app!',
                style: TextStyle(fontSize: 24, fontWeight: FontWeight.bold),
              ),
            ),
            ABTestUnit.widget(
              probability: 0.4,
              widget: Text(
                'Hello there!',
                style: TextStyle(fontSize: 20, color: Colors.blue),
              ),
            ),
          ]),
          
          SizedBox(height: 20),
          
          // Button variation
          ABTestManager.testUI([
            ABTestUnit.builder(
              probability: 0.5,
              widgetBuilder: () => ElevatedButton(
                onPressed: () {},
                child: Text('Get Started'),
                style: ElevatedButton.styleFrom(
                  backgroundColor: Colors.blue,
                  foregroundColor: Colors.white,
                ),
              ),
            ),
            ABTestUnit.builder(
              probability: 0.5,
              widgetBuilder: () => OutlinedButton(
                onPressed: () {},
                child: Text('Begin'),
                style: OutlinedButton.styleFrom(
                  foregroundColor: Colors.blue,
                ),
              ),
            ),
          ]),
        ],
      ),
    );
  }
}

API Reference

ABTestManager

The main class for managing A/B tests.

Methods

• static Widget testUI(List<ABTestUnit> units)
  • Takes a list of ABTestUnit objects and returns a widget based on probability
  • Throws an exception if the units list is empty
  • Throws an exception if the total probability exceeds 1.0

ABTestUnit

Represents a single UI variation in an A/B test.

Constructors

• ABTestUnit.widget({required double probability, required Widget widget})

  • Creates a unit with a direct widget
  • probability: The probability of this variation being selected (0.0 to 1.0)
  • widget: The widget to display

• ABTestUnit.builder({required double probability, required Widget Function() widgetBuilder})

  • Creates a unit with a widget builder function
  • probability: The probability of this variation being selected (0.0 to 1.0)
  • widgetBuilder: A function that returns the widget to display

• ABTestUnit({required double probability, required Widget widget})

  • Legacy constructor for backward compatibility

Methods

• Widget getWidget()
  • Returns the widget for this unit
  • Throws an exception if neither widget nor widgetBuilder is set

Important Notes

1. Probability Sum: The sum of all probabilities should equal 1.0. If it exceeds 1.0, an exception will be thrown.

2. Probability Validation: If the total probability is less than 1.0, a warning will be printed and the last unit will be returned as a fallback.

3. Random Selection: The selection is based on Random().nextDouble() from Dart's dart:math library.

4. Error Handling: The package includes comprehensive error handling for common issues like empty unit lists and invalid probabilities.

Additional information

Contributing

Feel free to contribute to this package by:

• Reporting bugs
• Suggesting new features
• Submitting pull requests

Issues

If you encounter any issues or have questions, please file an issue on the package repository.

License

This package is licensed under the same license as Flutter.