feature-toggles

Low-level feature toggle tools for Node and browsers.

Install

npm install --save @paralleldrive/feature-toggles

Use it

import {
  getCurrentActiveFeatureNames,
  isActiveFeatureName
} from '@paralleldrive/feature-toggles';

const initialFeatures = [
  {
    name: 'comments',
    isActive: true
  },
  {
    name: 'ratings',
    isActive: false
  },
  {
    name: 'faq',
    isActive: false
  },
  {
    name: 'help'
    isActive: false
  }
];

const req = { query: { ft: 'ratings,help' } };

const activeFeaturesNames = getCurrentActiveFeatureNames({
  initialFeatures,
  req
});

const isCommentsActive = isActiveFeatureName('comments', activeFeaturesNames); // true
const isRatingsActive = isActiveFeatureName('ratings', activeFeaturesNames); // true ( enabled via req query object )
const isFAQActive = isActiveFeatureName('faq', activeFeaturesNames); // false
const isHelpActive = isActiveFeatureName('help', activeFeaturesNames); // true ( enabled via req query object )

API

Interfaces

Feature

interface Feature {
  name: String,
  isActive: false,
  dependencies?: [...String]
}

Functions

activateFeatures

[...String] => [...Feature] => [...Feature]

Activates Features by name of the provided array of Features.

const initialFeatures = [
  { name: 'foo', isActive: true },
  { name: 'bar', isActive: false },
  { name: 'baz', isActive: false }
];

activateFeatures(['bar', 'baz'])(initialFeatures);

//
// [
//   { name: 'foo', isActive: true },
//   { name: 'bar', isActive: true },
//   { name: 'baz', isActive: true },
// ]
//

getActiveFeatureNames

([...Feature]) => [...String]

Takes an array of feature objects and returns an array of active feature names. This function respects Feature dependencies.

getBrowserQueryFeatureNames

Takes a window.location.search string and returns an array of active feature names. If search is not provided will grab the global window.location.search if available.

(search?) => [...String]

const search = '?ft=foo,bar,baz';

getBrowserQueryFeatureNames(search); // ['foo', 'bar', 'baz']

getCurrentActiveFeatureNames

Takes an array of initialFeatures, a req object, and a window.location.search string and returns an array of active feature names. If search is not provided will grab the global window.location.search if available. This function respects Feature dependencies.

({ initialFeatures = [...Feature], req? , search? }) => [...String])]

const initialFeatures = [
  { name: 'foo', isActive: true },
  { name: 'bar', isActive: false },
  { name: 'baz', isActive: false },
  { name: 'other': isActive: false }
]

getCurrentActiveFeatureNames({ initialFeatures }); // ['foo']

const req = {
  query:{
    ft='bar,baz'
  }
};

getCurrentActiveFeatureNames({ initialFeatures, req }); // ['foo', 'bar', 'baz']

getReqQueryFeatureNames

(req = {}) => [...String]

Takes a req object and returns an array of enabled feature names.

const req = {
  query:{
    ft='foo,bar,help'
  }
};

getReqQueryFeatureNames(req); // ['foo', 'bar', 'help']

getQueryFeatureNames

(query = {}) => [...String]

Takes a query object and returns an array of enabled feature names.

const query = { ft='foo,bar,help' }
getQueryFeatureNames(query); // ['foo', 'bar', 'help']

isActiveFeatureName

String => [...String] => boolean

Returns true if a feature name is in the array else it returns false.

const currentFeatures = ['foo', 'bar', 'baz'];
isActiveFeatureName('bar', currentFeatures); // true
isActiveFeatureName('cat', currentFeatures); // false

mergeFeatureNames

(...[...String]) => [...String]

Merge feature names without duplicating.

const currentFeatures = ['foo', 'bar', 'baz'];
mergeFeatureNames(currentFeatures, ['fish', 'bar', 'cat']); // ['foo', 'bar', 'baz', 'fish', 'cat']

removeFeatureNames

([...String], [...String]) => [...String]

Removes feature names

const currentFeatures = ['foo', 'bar', 'baz', 'cat'];
removeFeatureNames(currentFeatures, ['fish', 'bar', 'cat']); // ['foo', 'baz']