jashkenas--coffeescript/test/classes.coffee

# Classes
# -------

# * Class Definition
# * Class Instantiation
# * Inheritance and Super

test "classes with a four-level inheritance chain", ->

  class Base
    func: (string) ->
      "zero/#{string}"

    @static: (string) ->
      "static/#{string}"

  class FirstChild extends Base
    func: (string) ->
      super('one/') + string

  SecondChild = class extends FirstChild
    func: (string) ->
      super('two/') + string

  thirdCtor = ->
    @array = [1, 2, 3]

  class ThirdChild extends SecondChild
    constructor: -> thirdCtor.call this

    # Gratuitous comment for testing.
    func: (string) ->
      super('three/') + string

  result = (new ThirdChild).func 'four'

  ok result is 'zero/one/two/three/four'
  ok Base.static('word') is 'static/word'

  FirstChild::func = (string) ->
    super('one/').length + string

  result = (new ThirdChild).func 'four'

  ok result is '9two/three/four'

  ok (new ThirdChild).array.join(' ') is '1 2 3'


test "constructors with inheritance and super", ->

  identity = (f) -> f

  class TopClass
    constructor: (arg) ->
      @prop = 'top-' + arg

  class SuperClass extends TopClass
    constructor: (arg) ->
      identity super 'super-' + arg

  class SubClass extends SuperClass
    constructor: ->
      identity super 'sub'

  ok (new SubClass).prop is 'top-super-sub'


test "Overriding the static property new doesn't clobber Function::new", ->

  class OneClass
    @new: 'new'
    function: 'function'
    constructor: (name) -> @name = name

  class TwoClass extends OneClass
  delete TwoClass.new

  Function.prototype.new = -> new this arguments...

  ok (TwoClass.new('three')).name is 'three'
  ok (new OneClass).function is 'function'
  ok OneClass.new is 'new'

  delete Function.prototype.new


test "basic classes, again, but in the manual prototype style", ->

  Base = ->
  Base::func = (string) ->
    'zero/' + string
  Base::['func-func'] = (string) ->
    "dynamic-#{string}"

  FirstChild = ->
  SecondChild = ->
  ThirdChild = ->
    @array = [1, 2, 3]
    this

  ThirdChild extends SecondChild extends FirstChild extends Base

  FirstChild::func = (string) ->
    super('one/') + string

  SecondChild::func = (string) ->
    super('two/') + string

  ThirdChild::func = (string) ->
    super('three/') + string

  result = (new ThirdChild).func 'four'

  ok result is 'zero/one/two/three/four'

  ok (new ThirdChild)['func-func']('thing') is 'dynamic-thing'


test "super with plain ol' functions as the original constructors", ->

TopClass = (arg) ->
  @prop = 'top-' + arg
  this

SuperClass = (arg) ->
  super 'super-' + arg
  this

SubClass = ->
  super 'sub'
  this

SuperClass extends TopClass
SubClass extends SuperClass

ok (new SubClass).prop is 'top-super-sub'


test "'@' referring to the current instance, and not being coerced into a call", ->

  class ClassName
    amI: ->
      @ instanceof ClassName

  obj = new ClassName
  ok obj.amI()


test "super() calls in constructors of classes that are defined as object properties", ->

  class Hive
    constructor: (name) -> @name = name

  class Hive.Bee extends Hive
    constructor: (name) -> super

  maya = new Hive.Bee 'Maya'
  ok maya.name is 'Maya'


test "classes with JS-keyword properties", ->

  class Class
    class: 'class'
    name: -> @class

  instance = new Class
  ok instance.class is 'class'
  ok instance.name() is 'class'


test "Classes with methods that are pre-bound to the instance, or statically, to the class", ->

  class Dog
    constructor: (name) ->
      @name = name

    bark: =>
      "#{@name} woofs!"

    @static = =>
      new this('Dog')

  spark = new Dog('Spark')
  fido  = new Dog('Fido')
  fido.bark = spark.bark

  ok fido.bark() is 'Spark woofs!'

  obj = func: Dog.static

  ok obj.func().name is 'Dog'


test "a bound function in a bound function", ->

  class Mini
    num: 10
    generate: =>
      for i in [1..3]
        =>
          @num

  m = new Mini
  eq (func() for func in m.generate()).join(' '), '10 10 10'


test "contructor called with varargs", ->

  class Connection
    constructor: (one, two, three) ->
      [@one, @two, @three] = [one, two, three]

    out: ->
      "#{@one}-#{@two}-#{@three}"

  list = [3, 2, 1]
  conn = new Connection list...
  ok conn instanceof Connection
  ok conn.out() is '3-2-1'


test "calling super and passing along all arguments", ->

  class Parent
    method: (args...) -> @args = args

  class Child extends Parent
    method: -> super

  c = new Child
  c.method 1, 2, 3, 4
  ok c.args.join(' ') is '1 2 3 4'


test "classes wrapped in decorators", ->

  func = (klass) ->
    klass::prop = 'value'
    klass

  func class Test
    prop2: 'value2'

  ok (new Test).prop  is 'value'
  ok (new Test).prop2 is 'value2'


test "anonymous classes", ->

  obj =
    klass: class
      method: -> 'value'

  instance = new obj.klass
  ok instance.method() is 'value'


test "Implicit objects as static properties", ->

  class Static
    @static =
      one: 1
      two: 2

  ok Static.static.one is 1
  ok Static.static.two is 2


test "nothing classes", ->

  c = class
  ok c instanceof Function


test "classes with value'd constructors", ->

  counter = 0
  classMaker = ->
    inner = ++counter
    ->
      @value = inner

  class One
    constructor: classMaker()

  class Two
    constructor: classMaker()

  ok (new One).value is 1
  ok (new Two).value is 2
  ok (new One).value is 1
  ok (new Two).value is 2


test "exectuable class bodies", ->

  class A
    if true
      b: 'b'
    else
      c: 'c'

  a = new A

  eq a.b, 'b'
  eq a.c, undefined


test "mild metaprogramming", ->

  class Base
    @attr: (name) ->
      @::[name] = (val) ->
        if arguments.length > 0
          @["_#{name}"] = val
        else
          @["_#{name}"]

  class Robot extends Base
    @attr 'power'
    @attr 'speed'

  robby = new Robot

  ok robby.power() is undefined

  robby.power 11
  robby.speed Infinity

  eq robby.power(), 11
  eq robby.speed(), Infinity


test "namespaced classes do not reserve their function name in outside scope", ->

  one = {}
  two = {}

  class one.Klass
    @label = "one"

  class two.Klass
    @label = "two"

  eq typeof Klass, 'undefined'
  eq one.Klass.label, 'one'
  eq two.Klass.label, 'two'


test "nested classes", ->

  class Outer
    constructor: ->
      @label = 'outer'

    class @Inner
      constructor: ->
        @label = 'inner'

  eq (new Outer).label, 'outer'
  eq (new Outer.Inner).label, 'inner'


test "variables in constructor bodies are correctly scoped", ->

  class A
    x = 1
    constructor: ->
      x = 10
      y = 20
    y = 2
    captured: ->
      {x, y}

  a = new A
  eq a.captured().x, 10
  eq a.captured().y, 2


test "Issue #924: Static methods in nested classes", ->

  class A
    @B: class
      @c = -> 5

  eq A.B.c(), 5


test "`class extends this`", ->

  class A
    func: -> 'A'

  B = null
  makeClass = ->
    B = class extends this
      func: -> super + ' B'

  makeClass.call A

  eq (new B()).func(), 'A B'


test "ensure that constructors invoked with splats return a new object", ->

  args = [1, 2, 3]
  Type = (@args) ->
  type = new Type args

  ok type and type instanceof Type
  ok type.args and type.args instanceof Array
  ok v is args[i] for v, i in type.args

  Type1 = (@a, @b, @c) ->
  type1 = new Type1 args...

  ok type1 instanceof   Type1
  eq type1.constructor, Type1
  ok type1.a is args[0] and type1.b is args[1] and type1.c is args[2]

  # Ensure that constructors invoked with splats cache the function.
  called = 0
  get = -> if called++ then false else class Type
  new get() args...

test "`new` shouldn't add extra parens", ->

  ok new Date().constructor is Date


test "`new` works against bare function", ->

  eq Date, new ->
    eq this, new => this
    Date


test "#1182: a subclass should be able to set its constructor to an external function", ->
  ctor = ->
    @val = 1
  class A
  class B extends A
    constructor: ctor
  eq (new B).val, 1

test "#1182: external constructors continued", ->
  ctor = ->
  class A
  class B extends A
    method: ->
    constructor: ctor
  eq ctor, B
  ok B::method

test "#1313: misplaced __extends", ->
  nonce = {}
  class A
  class B extends A
    prop: nonce
    constructor: ->
  eq nonce, B::prop

test "#1182: execution order needs to be considered as well", ->
  counter = 0
  makeFn = (n) -> eq n, ++counter; ->
  class B extends (makeFn 1)
    @B: makeFn 2
    constructor: makeFn 3

test "#1182: external constructors with bound functions", ->
  fn = ->
  class B
  class A
    constructor: fn
    method: => this instanceof A
  ok (new A).method.call(new B)