create-mixin

Mix the prototype of one class into another

Usage no npm install needed!

<script type="module">
  import createMixin from 'https://cdn.skypack.dev/create-mixin';
</script>

README

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create-mixin

Useful for achieving something resembling multiple-inheritence in Javascript.

const mixInto = require('create-mixin')
const EventEmitter = require('events')

class EmittingArray extends mixInto(EventEmitter)(Array) {}

Example

Given these two classes.

class Base {
  constructor () {
    this.ranBaseConstructor = true
  }
  baseMethod () {
    return 1
  }
}

class Mixin {
  constructor () {
    this.ranMixinConstructor = true
  }
  someMethod () {
    return 2
  }
}

Create a new class mixing one class into another.

> const mixInto = require('create-mixin')

> class Something extends mixInto(Mixin)(Base) {}

Behaviour of new class.

> const something = new Something()

> /* new class has methods of both source classes */
> something.baseMethod()
1

> something.someMethod()
2

> /* Only the base constructor is run */
> something.ranBaseConstructor
true

> something.ranMixinConstructor
undefined

> something instanceof Base
true

> something instanceof Mixin
false

© 2018-19 Lloyd Brookes <75pound@gmail.com>.