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# Function Literals
# -----------------
# TODO: add indexing and method invocation tests: (->)[0], (->).call()
# * Function Definition
# * Bound Function Definition
# * Parameter List Features
# * Splat Parameters
# * Context (@) Parameters
# * Parameter Destructuring
# * Default Parameters
# Function Definition
x = 1
y = {}
y.x = -> 3
ok x is 1
ok typeof(y.x) is 'function'
ok y.x instanceof Function
ok y.x() is 3
# The empty function should not cause a syntax error.
->
() ->
# Multiple nested function declarations mixed with implicit calls should not
# cause a syntax error.
(one) -> (two) -> three four, (five) -> six seven, eight, (nine) ->
# with multiple single-line functions on the same line.
func = (x) -> (x) -> (x) -> x
ok func(1)(2)(3) is 3
# Make incorrect indentation safe.
func = ->
obj = {
key: 10
}
obj.key - 5
eq func(), 5
# Ensure that functions with the same name don't clash with helper functions.
del = -> 5
ok del() is 5
# Bound Function Definition
obj =
bound: ->
(=> this)()
unbound: ->
(-> this)()
nested: ->
(=>
(=>
(=> this)()
)()
)()
eq obj, obj.bound()
ok obj isnt obj.unbound()
eq obj, obj.nested()
test "even more fancy bound functions", ->
obj =
one: ->
do =>
return this.two()
two: ->
do =>
do =>
do =>
return this.three
three: 3
eq obj.one(), 3
test "self-referencing functions", ->
changeMe = ->
changeMe = 2
changeMe()
eq changeMe, 2
# Parameter List Features
test "splats", ->
arrayEq [0, 1, 2], (((splat...) -> splat) 0, 1, 2)
arrayEq [2, 3], (((_, _1, splat...) -> splat) 0, 1, 2, 3)
arrayEq [0, 1], (((splat..., _, _1) -> splat) 0, 1, 2, 3)
arrayEq [2], (((_, _1, splat..., _2) -> splat) 0, 1, 2, 3)
test "destructured splatted parameters", ->
arr = [0,1,2]
splatArray = ([a...]) -> a
splatArrayRest = ([a...],b...) -> arrayEq(a,b); b
arrayEq splatArray(arr), arr
arrayEq splatArrayRest(arr,0,1,2), arr
test "@-parameters: automatically assign an argument's value to a property of the context", ->
nonce = {}
((@prop) ->).call context = {}, nonce
eq nonce, context.prop
# allow splats along side the special argument
((splat..., @prop) ->).apply context = {}, [0, 0, nonce]
eq nonce, context.prop
# allow the argument itself to be a splat
((@prop...) ->).call context = {}, 0, nonce, 0
eq nonce, context.prop[1]
# the argument should still be able to be referenced normally
eq nonce, (((@prop) -> prop).call {}, nonce)
test "@-parameters and splats with constructors", ->
a = {}
b = {}
class Klass
constructor: (@first, splat..., @last) ->
obj = new Klass a, 0, 0, b
eq a, obj.first
eq b, obj.last
test "destructuring in function definition", ->
(([{a: [b], c}]...) ->
eq 1, b
eq 2, c
) {a: [1], c: 2}
test "default values", ->
nonceA = {}
nonceB = {}
a = (_,_1,arg=nonceA) -> arg
eq nonceA, a()
eq nonceA, a(0)
eq nonceB, a(0,0,nonceB)
eq nonceA, a(0,0,undefined)
eq nonceA, a(0,0,null)
eq false , a(0,0,false)
eq nonceB, a(undefined,undefined,nonceB,undefined)
b = (_,arg=nonceA,_1,_2) -> arg
eq nonceA, b()
eq nonceA, b(0)
eq nonceB, b(0,nonceB)
eq nonceA, b(0,undefined)
eq nonceA, b(0,null)
eq false , b(0,false)
eq nonceB, b(undefined,nonceB,undefined)
c = (arg=nonceA,_,_1) -> arg
eq nonceA, c()
eq 0, c(0)
eq nonceB, c(nonceB)
eq nonceA, c(undefined)
eq nonceA, c(null)
eq false , c(false)
eq nonceB, c(nonceB,undefined,undefined)
test "default values with @-parameters", ->
a = {}
b = {}
obj = f: (q = a, @p = b) -> q
eq a, obj.f()
eq b, obj.p
test "default values with splatted arguments", ->
withSplats = (a = 2, b..., c = 3, d = 5) -> a * (b.length + 1) * c * d
eq 30, withSplats()
eq 15, withSplats(1)
eq 5, withSplats(1,1)
eq 1, withSplats(1,1,1)
eq 2, withSplats(1,1,1,1)
test "default values with function calls", ->
doesNotThrow -> CoffeeScript.compile "(x = f()) ->"
test "arguments vs parameters", ->
doesNotThrow -> CoffeeScript.compile "f(x) ->"
f = (g) -> g()
eq 5, f (x) -> 5
test "#1844: bound functions in nested comprehensions causing empty var statements", ->
a = ((=>) for a in [0] for b in [0])
eq 1, a.length
test "#1859: inline function bodies shouldn't modify prior postfix ifs", ->
list = [1, 2, 3]
ok true if list.some (x) -> x is 2
test "#2258: allow whitespace-style parameter lists in function definitions", ->
func = (
a, b, c
) -> c
eq func(1, 2, 3), 3
func = (
a
b
c
) -> b
eq func(1, 2, 3), 2
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