mixly

Collection of mixin tools for objects and functions.

Table of Contents

• Install
• API
  • mixly
  • append
  • chain
  • copy
  • extend
  • funky
  • immutable
  • inherit
• License

Install

$ npm install --save mixly

API

mixly

mixly(object[, object[, ...object]])

Alias: mixly/mixin

Creates prototype chain with the properties from the provided objects, by (shallow) copying own properties from each object onto respective elements in the chain.

var mixly = require('mixly');

var o1 = { O1: true, commonThing: 'o1' }
  , o2 = { O2: true, commonThing: 'o2' }
  , o3 = { O3: true, commonThing: 'o3' }
  ;

// (o1) -> (o2) -> (o3)
var o0 = mixly(o1, o2, o3);

assert.notStrictEqual(Object.getPrototypeOf(o0), o1, 'Object `o0` does not have prototype set to object `o1`');
assert.notStrictEqual(Object.getPrototypeOf(o1), o2, 'Object `o1` does not have prototype set to object `o2`');
assert.notStrictEqual(Object.getPrototypeOf(o2), o3, 'Object `o2` does not have prototype set to object `o3`');

assert.strictEqual(o0.O1, true, 'copied properties from the first object');
assert.strictEqual(o0.O2, true, 'has access to the properties of the second object');
assert.strictEqual(o0.O3, true, 'has access to the properties of the third object');
assert.strictEqual(o0.commonThing, 'o1', 'shared properties from first object "win"');
assert.strictEqual(Object.getPrototypeOf(o0).commonThing, 'o2', 'has access to the shared properties of the second object');
assert.strictEqual(Object.getPrototypeOf(Object.getPrototypeOf(o0)).commonThing, 'o3', 'has access to the shared properties of the third object');

assert.strictEqual(o0.hasOwnProperty('commonThing'), true, 'has shared properties from first object as own');
assert.strictEqual(o0.hasOwnProperty('O1'), true, 'has shared properties from first object as own');
assert.strictEqual(o0.hasOwnProperty('O2'), false, 'does not own properties from the second object');
assert.strictEqual(o0.hasOwnProperty('O3'), false, 'does not own properties from the third object');

More details in test/mixin.js test file.

append

mixly.append(object[, object[, ...object]])

Aliases: mixly/append, mixly/flat

Appends objects' properties (shallow copy) into the first object.

var append = require('mixly/append');

var o1 = { O1: true, commonThing: 'o1' }
  , o2 = { O2: true, commonThing: 'o2' }
  , o3 = { O3: true, commonThing: 'o3' }
  ;

// o1 + o2 + o3
var oX = append(o1, o2, o3);

assert.strictEqual(oX, o1, 'first argument was modified');
assert.strictEqual(oX.O1, true, 'kept properties from the first object');
assert.strictEqual(oX.O2, true, 'obtained properties from the second object');
assert.strictEqual(oX.O3, true, 'obtained properties from the third object');
assert.strictEqual(oX.commonThing, 'o3', 'last object in the list overrides shared properties');

More details in test/append.js test file.

chain

mixly.chain(object[, object[, ...object]])

Aliases: mixly/chain, mixly/proto

Modifies prototype chain for the provided objects, based on the order of the arguments.

var chain = require('mixly/chain');

var o1 = { O1: true, commonThing: 'o1' }
  , o2 = { O2: true, commonThing: 'o2' }
  , o3 = { O3: true, commonThing: 'o3' }
  ;

// o1 -> o2 -> o3
mixly.chain(o1, o2, o3);

assert.strictEqual(Object.getPrototypeOf(o1), o2, 'Object `o1` has prototype set to object `o2`');
assert.strictEqual(Object.getPrototypeOf(o2), o3, 'Object `o2` has prototype set to object `o3`');

assert.strictEqual(o1.O1, true, 'kept properties from the first object');
assert.strictEqual(o1.O2, true, 'has access to the properties of the second object');
assert.strictEqual(o1.O3, true, 'has access to the properties of the third object');
assert.strictEqual(o1.commonThing, 'o1', 'kept own shared properties');
assert.strictEqual(Object.getPrototypeOf(o1).commonThing, 'o2', 'has access to the shared properties of the second object');
assert.strictEqual(Object.getPrototypeOf(Object.getPrototypeOf(o1)).commonThing, 'o3', 'has access to the shared properties of the third object');

assert.strictEqual(o1.hasOwnProperty('commonThing'), true, 'kept own shared properties');
assert.strictEqual(o1.hasOwnProperty('O1'), true, 'kept own unique properties');
assert.strictEqual(o1.hasOwnProperty('O2'), false, 'does not own properties from the second object');
assert.strictEqual(o1.hasOwnProperty('O3'), false, 'does not own properties from the third object');

More details in test/chain.js test file.

copy

mixly.copy(object, object)

Alias: mixly/copy

Copies (shallow) own properties between provided objects. Used internally by other mixly methods.

var copy = require('mixly/copy');

var o1 = { O1: true, commonThing: 'o1' }
  , o2 = { O2: true, commonThing: 'o2' }
  ;

// o1 + o2
var oX = copy(o1, o2);

assert.strictEqual(oX, o1, 'first argument was modified');
assert.strictEqual(oX.O1, true, 'kept properties from the first object');
assert.strictEqual(oX.O2, true, 'obtained properties from the second object');
assert.strictEqual(oX.commonThing, 'o2', 'last object in the list overrides shared properties');

More details in test/copy.js test file.

extend

mixly.extend(function, function)

Alias: mixly/extend

Extends target class with superclass, assigns superclass prototype as prototype of the target class and adds superclass itself as __proto__ of the target class, allowing "static" methods inheritance.

var extend = require('mixly/extend');

function F1()
{
  F1.super_.apply(this, arguments);
  this.p0 += 'd2';
}
F1.prototype.p1 = 'f1';
F1.static1 = true;

function F2()
{
  this.p0 = 'r2';
}
F2.prototype.p2 = 'f2';
F2.static2 = true;

// F1 -> F2
extend(F1, F2);

assert.strictEqual('p1' in F1.prototype, false, 'original prototype is gone');
assert.strictEqual('p2' in F1.prototype, true, 'replaced with new prototype');

assert.strictEqual(F1.static1, true, 'original static property is accessible');
assert.strictEqual(F1.static2, true, 'extended static property is accessible');

// new instance
var f1 = new F1();

assert.strictEqual(f1.p0, 'r2d2', 'constructor executes provided super constructor');

More details in test/extend.js test file.

funky

mixly.funky(function[, function[, ...function]])

Alias: mixly/funky

Creates prototype chain from the provided functions, by (shallow) copying prototypes from each function onto respective elements in the chain.

var funky = require('mixly/funky');

function F1()
{
  this.super_.apply(this, arguments);
  this.f1 = true;
}
F1.prototype.f1p = true;

function F2()
{
  // this.super_ is reference to itself
  // we're in the f0 context
  // don't call super_.super_
  this.f2 = true;
}
F2.prototype.f2p = true;

function F3()
{
  // never gets here
  this.f3 = true;
}
F3.prototype.f3p = true;

// F0 -> (F1) -> (F2) -> (F3)
var F0 = mixly.clone(F1, F2, F3);
var f0 = new F0();

assert.notStrictEqual(F0.prototype, F1.prototype, 'is not exactly F1');
assert.strictEqual(F0.prototype.f1p, true, 'but close');

F0.prototype.bla = 42;
assert.strictEqual('bla' in F1.prototype, false, 'F1 stays untouched');

assert.strictEqual(f0.f1, true, 'executed F1 constructor');
assert.strictEqual(f0.f2, true, 'executed F2 constructor');
assert.strictEqual('f3' in f0, false, 'skipped F3 constructor');

assert.strictEqual(f0.f1p, true, 'inherited F1 prototype properties');
assert.strictEqual(f0.f2p, true, 'inherited F2 prototype properties');
assert.strictEqual(f0.f3p, true, 'inherited F3 prototype properties');

More details in test/funky.js test file.

immutable

mixly.immutable(object[, object[, ...object]])

Alias: mixly/immutable

Creates immutable (shallow) copy of the provided objects. Similar to append, but doesn't modify any of the provided objects.

var immutable = require('mixly/immutable');

var o1 = { O1: true, commonThing: 'o1' }
  , o2 = { O2: true, commonThing: 'o2' }
  , o3 = { O3: true, commonThing: 'o3' }
  ;

// oX + o1 + o2 + o3
var oX = immutable(o1, o2, o3);

assert.notStrictEqual(oX, o1, 'first argument was not modified');

assert.strictEqual(oX.O1, true, 'kept properties from the first object');
assert.strictEqual(oX.O2, true, 'obtained properties from the second object');
assert.strictEqual(oX.O3, true, 'obtained properties from the third object');
assert.strictEqual(oX.commonThing, 'o3', 'last object in the list overrides shared properties');

More details in test/immutable.js test file.

inherit

mixly.inherit(function, function)

Alias: mixly/inherit

Assigns prototype from the superclass to the target class, compatible with node's builtin version (util.inherit), but browser-friendly (without browserify magic, i.e. works with other packagers).

var inherit = require('mixly/inherit');

function Child() { Parent.call(this); }
function Parent() {}

// Child -> Parent
inherit(Child, Parent);

// create instance
var child = new Child();

assert.strictEqual(child.constructor.super_, Parent, 'child has reference to the Parent constructor');
assert.strictEqual(Object.getPrototypeOf(Object.getPrototypeOf(child)), Parent.prototype, 'child has Parent in the prototype chain');
assert.strictEqual(child instanceof Child, true, 'child instance of Child');
assert.strictEqual(child instanceof Parent, true, 'child instance of Parent');

More details in test/inherit.js test file.

License

Mixly is released under the MIT license.