Super Mixer

Mixes/merges/extends your object in multiple ways.

Unlike underscore/lodash utility methods this module allows you to:

mix or deep merge objects' prototype chain. Regular mixin/extend/assign implementations can't do that.
mix or deep merge unique properties only. I.e. data will not be overwritten if a property already exists.
filter each individual property by target value, source value, and key. See API.
transform each value by resulting value, source value, and key. See API.

Install

$ npm install supermixer

var mixer = require('supermixer');

API

NB! All functions always mutate the first argument.

supermixer(opts = {})

The opts:

 * @param {Object} opts
 * @param {Function} opts.filter Function which filters value and key.
 * @param {Function} opts.transform Function which transforms each value.
 * @param {Boolean} opts.chain Loop through prototype properties too.
 * @param {Boolean} opts.deep Deep looping through the nested properties.
 * @param {Boolean} opts.noOverwrite Do not overwrite any existing data (aka first one wins).

Usage:

const mix = supermixer({
  filter(sourceValue, targetValue, key) { return key[0] !== '_'; }, // do not copy "private" values
  transform(resultValue, targetValue, key) { console.log(key); return resultValue; }, // log each key which gets set
  chain: true,
  deep: true,
  noOverwrite: true
});

const johnStream = mix({}, new Stream(), { name: "John Stream"; })

Regular mixin, aka `Object.assign`, aka `$.extend`.

 // the regular Object.assign function
var extend = supermixer();
// OR
extend = supermixer.mixin;

extend({}, { a: 1 }, { b: 2 });
// { a: 1, b: 2 }

Mixin functions only.

// assigns own functions only
var functionMixer = supermixer({
  filter: function (sourceValue) { return typeof sourceValue === 'function'; }
});
// OR
functionMixer = supermixer.mixinFunctions;

functionMixer({}, { a: "x" },  { b: function(){} });
// { b() }

Mixin functions including prototype chain.

// assigns functions only, but traverse through the prototype chain
var chainFunctionMixer = supermixer({
  filter: function (sourceValue) { return typeof sourceValue === 'function'; },
  chain: true
});
// OR
chainFunctionMixer = supermixer.mixinChainFunctions;

chainFunctionMixer({}, new EventEmitter());
// { on(), off(), emit(), ... }

Deep merge

// deep merge own properties
var mergeDeep = supermixer({
  deep: true
});
// OR
mergeDeep = supermixer.merge;

mergeDeep({ url: { host: "example.com" } }, { url: { port: 81 } });
// { url: { host: "example.com", port: 81 } }

Deep merge but do not overwrite existing values.

// deep merge own properties
var mergeDeep = supermixer({
  deep: true,
  noOverwrite: true
});
// OR
mergeUnique = supermixer.mergeUnique;

mergeUnique({ url: { host: "example.com" } }, { url: { host: "evil.com" } });
// { url: { host: "example.com" } }

Deep merge non functions including prototype chain.

// deeply merges data properties, traversing through prototype chain
var mergeChainData =  supermixer({
  filter: function (sourceValue) { return typeof sourceValue !== 'function'; },
  deep: true,
  chain: true
});
// OR
mergeChainData = supermixer.mergeChainNonFunctions;

EventEmitter.prototype.hello = "world";
mergeChainData({}, new EventEmitter());
// { hello: "world" }

Want to contribute?

This project is Open Open Source. This means whoever submits an accepted PR will receive write permissions to the project.

Current Tags

1.0.5 ... latest (4 years ago)