Simple OOP for JavaScript

npm install jassino
4 downloads in the last month

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What is it?

Light, fast, small and well unit-tested OOP in Javascript.

Why yet another one? Because of specific syntax sugar, to make things just handy.


  • Backed by native Javascript prototypes, definitions processing at declaration-time, almost no instantiation-time overhead
  • Single inheritance from base class
  • Simple and handy Traits with multiple inheritance
  • Compact shortcuts for a constructor
  • Getters/setters generation for pseudo-properties
  • Any level of inheritance allowed (up to your stack size :), calls to super class constructor/methods work well
  • Compatible with usual prototype-bases pseudo classes - you may inherit Jassino class from mere function
  • "instance constants" in classes and traits
  • cross-browser, no dependencies
  • less then 4Kb minified !


  • All browsers except Internet Explorer cross-frame
  • Google Apps Script


  • v0.5.0 - breaking changes, shortcut constructor changes for super case:
       'super_a, super_b, ... ## c, d,...',
       jassino is now compatible with CoffeeScript 'super' call for ancestor methods, and super constructor
       in case of explicit declaration of constructor in derived class
       Error reporting on parameters improved.
  • v0.4 - breaking changes, shortcut constructors ['par1', 'par2', ...] ->
       'par1, par2,...', for super constructor [['a', 'b',...]['c', 'd',...]] - > ['a, b, ...', 'c, d,...']
  • v0.3 - first stable version

Detailed capabilities of the library may be seen from unit-test examples

At a glance

test("Rewritten example from my-class (http://myjs.fr/my-class/) - NO INFINITE RECURSION!", 1, function() {
    var N = Jassino.NS

    Class('Person', {
        old_method: function(){ return "Hey!, "},
        _: function(name){this.name=name}  //constructor

    Class('Dreamer', N.Person, {
        _:'name ## dream'  //constructor shortcut: name -> super call, dream -> this.dream

    var custom_ns = {}
    Class(custom_ns, 'Nightmarer', N.Dreamer, {
        field: "dreams about",  //"instance constant" - added to every instance, may be overridden in constructor

        old_method: function(){ return "Okay, "}, //overriding

        _:function(name, dream){
            this.Dreamer(name, dream)
            this.field = this.field.toUpperCase() //control flow should be reached and field created
        test: function(){ return this.Dreamer.do("old_method") + 
                                 this.old_method() +
                                 this.name + " " + this.field + " " + this.dream}


    var nm = new custom_ns.Nightmarer("Lissa", "Pie")

    strictEqual(nm.test(), "Hey!, Okay, Lissa DREAMS ABOUT Pie", "test to not go into infinite recursion!")



Just include jassino.min.js into your javascript bundle/project.

Google Apps Script

Install as library, docs here

Remember that you will have to specify your library name, when using in script like Mylib.Jassino.Class, I'd recommend to make a shortcut

Also in GAS you will not be able to use Jassino.use_global_scope() with global object and default namespace (Jassino.NS) if Jassino library have no write permissions


You may rebuild it from source running ./build_min.sh, provided you have nodejs installed.

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