Features Manager

A lightweight TypeScript-based features manager that enables conditional feature activation based on user-specific rules, including username and location-based rules, and percentage rollouts.

Description

The Features Manager is designed to help developers manage the visibility of features in their applications. It allows for conditional activation based on user-specific rules (including user IDs and usernames), location-specific rules (city, state, country), and percentage rollouts, providing a flexible and controlled way to release features.

How To Get Started

Installation

To install the package, run:

npm install features-manager

Initialization

Create an instance of the FeaturesManager with your feature configurations:

import FeaturesManager from 'features-manager';


const featureFlag = new FeaturesManager({
  flags: {
    newDashboard: {
      enabled: true,
      users: ['john_doe', 'jane_smith'],
      locations: ['New York', 'California', 'USA'],
      percentage: 25,
    },
    darkMode: {
      enabled: false,
    },
    premiumFeature: {
      enabled: true,
      users: ['john_doe'],
    },
    betaFeature: {
      enabled: true,
      percentage: 50,
    },
    stableFeature: {
      enabled: true,
    },
  },
});

Example Usage

import featureFlag from './featureFlag'; // assuming your feature flag instance is in featureFlag.ts

const userContext = {
  userId: 'john_doe',
  username: 'john_doe',
};

const locationContext = {
  city: 'New York',
  state: 'New York',
  country: 'USA',
};

// Check if the 'newDashboard' feature is enabled for the given user and location context
const isNewDashboardEnabled = featureFlag.isFeatureEnabled('newDashboard', userContext, locationContext);
console.log(`Is New Dashboard Enabled: ${isNewDashboardEnabled}`); // true

// Check if the 'darkMode' feature is enabled for the given user and location context
const isDarkModeEnabled = featureFlag.isFeatureEnabled('darkMode', userContext, locationContext);
console.log(`Is Dark Mode Enabled: ${isDarkModeEnabled}`); // false

// Check if the 'premiumFeature' is enabled for the given user and location context
const isPremiumFeatureEnabled = featureFlag.isFeatureEnabled('premiumFeature', userContext, locationContext);
console.log(`Is Premium Feature Enabled: ${isPremiumFeatureEnabled}`); // true

// Check if the 'betaFeature' is enabled for the given user
const isBetaFeatureEnabled = featureFlag.isFeatureEnabled('betaFeature', userContext, locationContext);
console.log(`Is Beta Feature Enabled: ${isBetaFeatureEnabled}`); // The output will be true or false based on percentage rollout

// Check if the 'stableFeature' is enabled for the given user
const isStableFeatureEnabled = featureFlag.isFeatureEnabled('stableFeature', userContext, locationContext);
console.log(`Is Stable Feature Enabled: ${isStableFeatureEnabled}`); // true

Sample Outputs

1. Feature: newDashboard

   • User ID: john_doe
   • Username: john_doe
   • Location: New York, New York, USA
   • Output: true (enabled for this user and location)

2. Feature: darkMode

   • User ID: unknown_user
   • Location: California, USA
   • Output: false (feature is disabled)

3. Feature: premiumFeature

   • User ID: john_doe
   • Output: true (enabled for this user)

4. Feature: betaFeature

   • User ID: john_doe
   • Username: john_doe
   • Location: New York, New York, USA
   • Output: true or false (depends on percentage rollout)

5. Feature: stableFeature

   • User ID: john_doe
   • Username: john_doe
   • Location: New York, New York, USA
   • Output: true (feature is enabled)

Benefits

• User-Specific Rules: Target features to specific users by ID or username.
• Location-Based Rules: Enable features based on user's city, state, or country.
• Percentage Rollouts: Gradually roll out features to a percentage of users.
• Flexible Configuration: Easily manage feature flags through a centralized configuration.

This Features Manager provides a simple yet powerful way to manage feature visibility and ensure controlled feature rollouts, improving your development workflow and user experience.

Author: Micheal Ighietsemhe