ember-feature-flags

An ember-cli addon to provide feature flags.

Installation

ember install ember-feature-flags

Usage

This addon injects a property features (configurable) into your routes, controllers and components.

For example you may check if a feature is enabled:

export default Ember.Controller.extend({
  plans: function(){
    if (this.features.isEnabled('new-billing-plans')){
      // Return new plans
    } else {
      // Return old plans
    }
  }.property()
});

Features are also available as properties of features. They are camelized.

export default Ember.Controller.extend({
  plans: function(){
    if (this.features.get('newBillingPlans')){
      // Return new plans
    } else {
      // Return old plans
    }
  }.property('features.newBillingPlans')
});

Check whether a feature is enabled in a template:

{{#if features.newHomepage}}
  {{link-to "new.homepage"}}
{{else}}
  {{link-to "old.homepage"}}
{{/if}}

Features can be toggled at runtime, and are bound:

features.enable('newHomepage');
features.disable('newHomepage');

Features can be set in bulk:

features.setup({
  "new-billing-plans": true,
  "new-homepage": false
});

Configuration

config.featureFlags

You can configure a set of initial feature flags in your app's config/environment.js file. This is an easy way to change settings for a given environment. For example:

// config/environment.js
module.exports = function(environment) {
  var ENV = {
    featureFlags: {
      'show-spinners': true,
      'download-cats': false
    }
  };

  if (environment === 'production') {
    ENV.featureFlags['download-cats'] = true;
  }

  return ENV;
};

config.featureFlagsService

The name of the features injection can be customized with the featureFlagsService config option. For example:

// config/environment.js
module.exports = function(environment) {
  var ENV = {
    featureFlagsService: 'featuresService'
  };
  return ENV;
};

ENV.LOG_FEATURE_FLAG_MISS

Will log when a feature flag is queried and found to be off, useful to prevent cursing at the app, wondering why your feature is not working.

Test Helpers

withFeature

Turns on a feature for the test in which it is called. To use, import into your test-helper.js: import '<app-name>/tests/helpers/with-feature' and add to your test .jshintrc, it will now be available in all of your tests.

Example:

import '<app-name>/tests/helpers/with-feature';

test( "links go to the new homepage", function () {
  withFeature( 'new-homepage' );

  visit('/');
  click('a.home');
  andThen(function(){
    equal(currentRoute(), 'new.homepage', 'Should be on the new homepage');
  });
});

Integration Tests

If you use this.features.isEnabled() in components under integration test, you will need to inject a stub service in your tests. Using ember-qunit 0.4.16 or later, here's how to do this:

const { getOwner } = Ember;

let featuresService = Ember.Service.extend({
  isEnabled() {
    return false;
  }
});

moduleForComponent('my-component', 'Integration | Component | my component', {
  integration: true,
  beforeEach() {
    this.register('service:features', featuresService);
    getOwner(this).inject('component', 'features', 'service:features');
  }
});

Note: for Ember before 2.3.0, you'll need to use ember-getowner-polyfill.

Development

Installation

• git clone this repository
• npm install
• bower install

Running

• ember server
• Visit your app at http://localhost:4200.

Running Tests

• ember test
• ember test --server

Building

• ember build