README.md

React-Enable for feature flags

Easy and fast way to toggle features in your project.

Features include:

• Toggle parts of your project dynamically or at startup
• Built in state management for active features
• Roll your own state manager using the minimal functional interface

Installation and usage

To install,

npm add --save react-enable react

Then most users will use it in the following manner:

import React, { lazy } from 'react';
import { Features, ToggleFeatures, Disable, Enable, FeatureDescription } from 'react-enable';

const NewVersion = lazy(() => import('./src/new-version'));
const OldVersion = lazy(() => import('./src/old-version'));

// All available features should be declared up-front, with default values
const FEATURES: FeatureDescription[] = [{ name: 'v2', defaultValue: true }];

function RestOfApp(): JSX.Element {
  return (
    <div>
      <Enable feature="v2">
        <NewVersion />
      </Enable>
      <Disable feature="v2">
        <OldVersion />
      </Disable>
    </div>
  );
}

function App(): JSX.Element {
  return (
    <Features features={FEATURES}>
      <RestOfApp />
      <ToggleFeatures />
    </Features>
  );
}

Documentation

Features component

Provides state and context for managing a set of features.

Available props:

• features: FeatureDescription[]: description of available features.
• disableConsole?: boolean: indicate the console API should not be enabled (default false)
• storage?: Storage: where to persist overrides (default window.sessionStorage)

Enabled and Disabled components

Render children depending on which set of features are active.

Props:

• feature: string | string[]: if one of these is enabled, the children will render (or not, with Disabled)
• allFeatures: string[]: only if all the specified features are enabled will it render children (or not, with Disabled)

Hooks

• useEnabled(features: string | string[]): return true if any specified features are enabled.
• useAllEnabled(features: string | string[]): return true if all specified features are enabled.
• useAllDisabled(features: string | string[]): return true if all specified features are disabled.
• useDisabled(features: string | string[]): return true iff any specified features are disabled.

ToggleFeatures component

Renders all current features specified in Features, and whether they are enabled or disabled, with checkboxes to toggle them. Rendered HTML has class toggle-features for custom styling. You might use this in a Portal, and style it to float on top of the screen in developer builds.

EnableContext component

This component can be used if you want to do your own state management or custom feature storage. Instead of using Features, you would wrap your tree, providing a custom test function.

  return (
    <EnableContext.Provider test={feature => myCustomFeatureEnabled(feature)}>
      ...
    </EnableContext.Provider>
  >

console Interface

In addition to ToggleFeatures, it is possible to toggle features on the console, if configured. To enable pass a boolean to consoleOverride prop (you might want to feed this from an environment variable for dev vs prod builds, for example):

<Features features={FEATURES}>
  <RestOfApp />
</Features>

Then in the browser console, you can use features:

// toggle feature from enabled<->disabled, unset->enabled
window.feature.toggle('foo');

// force to enabled or disabled, respectively
window.feature.enable('foo');
window.feature.disable('foo');

// Unset the override, and hence let the default take over
window.feature.unset('foo');

// show all configured feature names and the current state of the feature
window.feature.listFeatures();

This can be useful for toggling features in production builds.