mirror of
https://github.com/jashkenas/coffeescript.git
synced 2022-11-09 12:23:24 -05:00
6d9553a016
This let's you do things like:
fullName = ({first = 'John', last = 'Doe'}) -> "#{first} #{last}"
Note: CoffeeScrits treats `undefined` and `null` the same, and that's true in
the case of destructuring defaults as well, as opposed to ES2015 which only uses
the default value if the target is `undefined`. A similar ES2015 difference
already exists for function parameter defaults. It is important for CoffeeScript
to be consistent with itself.
fullName2 = (first = 'John', last = 'Doe') -> "#{first} #{last}"
assert fullName('Bob', null) is fullName2(first: 'Bob', last: null)
Fixes #1558, #3288 and #4005.
572 lines
14 KiB
CoffeeScript
572 lines
14 KiB
CoffeeScript
# Assignment
|
|
# ----------
|
|
|
|
# * Assignment
|
|
# * Compound Assignment
|
|
# * Destructuring Assignment
|
|
# * Context Property (@) Assignment
|
|
# * Existential Assignment (?=)
|
|
# * Assignment to variables similar to generated variables
|
|
|
|
test "context property assignment (using @)", ->
|
|
nonce = {}
|
|
addMethod = ->
|
|
@method = -> nonce
|
|
this
|
|
eq nonce, addMethod.call({}).method()
|
|
|
|
test "unassignable values", ->
|
|
nonce = {}
|
|
for nonref in ['', '""', '0', 'f()'].concat CoffeeScript.RESERVED
|
|
eq nonce, (try CoffeeScript.compile "#{nonref} = v" catch e then nonce)
|
|
|
|
# Compound Assignment
|
|
|
|
test "boolean operators", ->
|
|
nonce = {}
|
|
|
|
a = 0
|
|
a or= nonce
|
|
eq nonce, a
|
|
|
|
b = 1
|
|
b or= nonce
|
|
eq 1, b
|
|
|
|
c = 0
|
|
c and= nonce
|
|
eq 0, c
|
|
|
|
d = 1
|
|
d and= nonce
|
|
eq nonce, d
|
|
|
|
# ensure that RHS is treated as a group
|
|
e = f = false
|
|
e and= f or true
|
|
eq false, e
|
|
|
|
test "compound assignment as a sub expression", ->
|
|
[a, b, c] = [1, 2, 3]
|
|
eq 6, (a + b += c)
|
|
eq 1, a
|
|
eq 5, b
|
|
eq 3, c
|
|
|
|
# *note: this test could still use refactoring*
|
|
test "compound assignment should be careful about caching variables", ->
|
|
count = 0
|
|
list = []
|
|
|
|
list[++count] or= 1
|
|
eq 1, list[1]
|
|
eq 1, count
|
|
|
|
list[++count] ?= 2
|
|
eq 2, list[2]
|
|
eq 2, count
|
|
|
|
list[count++] and= 6
|
|
eq 6, list[2]
|
|
eq 3, count
|
|
|
|
base = ->
|
|
++count
|
|
base
|
|
|
|
base().four or= 4
|
|
eq 4, base.four
|
|
eq 4, count
|
|
|
|
base().five ?= 5
|
|
eq 5, base.five
|
|
eq 5, count
|
|
|
|
eq 5, base().five ?= 6
|
|
eq 6, count
|
|
|
|
test "compound assignment with implicit objects", ->
|
|
obj = undefined
|
|
obj ?=
|
|
one: 1
|
|
|
|
eq 1, obj.one
|
|
|
|
obj and=
|
|
two: 2
|
|
|
|
eq undefined, obj.one
|
|
eq 2, obj.two
|
|
|
|
test "compound assignment (math operators)", ->
|
|
num = 10
|
|
num -= 5
|
|
eq 5, num
|
|
|
|
num *= 10
|
|
eq 50, num
|
|
|
|
num /= 10
|
|
eq 5, num
|
|
|
|
num %= 3
|
|
eq 2, num
|
|
|
|
test "more compound assignment", ->
|
|
a = {}
|
|
val = undefined
|
|
val ||= a
|
|
val ||= true
|
|
eq a, val
|
|
|
|
b = {}
|
|
val &&= true
|
|
eq val, true
|
|
val &&= b
|
|
eq b, val
|
|
|
|
c = {}
|
|
val = null
|
|
val ?= c
|
|
val ?= true
|
|
eq c, val
|
|
|
|
test "#1192: assignment starting with object literals", ->
|
|
doesNotThrow (-> CoffeeScript.run "{}.p = 0")
|
|
doesNotThrow (-> CoffeeScript.run "{}.p++")
|
|
doesNotThrow (-> CoffeeScript.run "{}[0] = 1")
|
|
doesNotThrow (-> CoffeeScript.run """{a: 1, 'b', "#{1}": 2}.p = 0""")
|
|
doesNotThrow (-> CoffeeScript.run "{a:{0:{}}}.a[0] = 0")
|
|
|
|
|
|
# Destructuring Assignment
|
|
|
|
test "empty destructuring assignment", ->
|
|
{} = [] = undefined
|
|
|
|
test "chained destructuring assignments", ->
|
|
[a] = {0: b} = {'0': c} = [nonce={}]
|
|
eq nonce, a
|
|
eq nonce, b
|
|
eq nonce, c
|
|
|
|
test "variable swapping to verify caching of RHS values when appropriate", ->
|
|
a = nonceA = {}
|
|
b = nonceB = {}
|
|
c = nonceC = {}
|
|
[a, b, c] = [b, c, a]
|
|
eq nonceB, a
|
|
eq nonceC, b
|
|
eq nonceA, c
|
|
[a, b, c] = [b, c, a]
|
|
eq nonceC, a
|
|
eq nonceA, b
|
|
eq nonceB, c
|
|
fn = ->
|
|
[a, b, c] = [b, c, a]
|
|
arrayEq [nonceA,nonceB,nonceC], fn()
|
|
eq nonceA, a
|
|
eq nonceB, b
|
|
eq nonceC, c
|
|
|
|
test "#713: destructuring assignment should return right-hand-side value", ->
|
|
nonces = [nonceA={},nonceB={}]
|
|
eq nonces, [a, b] = [c, d] = nonces
|
|
eq nonceA, a
|
|
eq nonceA, c
|
|
eq nonceB, b
|
|
eq nonceB, d
|
|
|
|
test "destructuring assignment with splats", ->
|
|
a = {}; b = {}; c = {}; d = {}; e = {}
|
|
[x,y...,z] = [a,b,c,d,e]
|
|
eq a, x
|
|
arrayEq [b,c,d], y
|
|
eq e, z
|
|
|
|
test "deep destructuring assignment with splats", ->
|
|
a={}; b={}; c={}; d={}; e={}; f={}; g={}; h={}; i={}
|
|
[u, [v, w..., x], y..., z] = [a, [b, c, d, e], f, g, h, i]
|
|
eq a, u
|
|
eq b, v
|
|
arrayEq [c,d], w
|
|
eq e, x
|
|
arrayEq [f,g,h], y
|
|
eq i, z
|
|
|
|
test "destructuring assignment with objects", ->
|
|
a={}; b={}; c={}
|
|
obj = {a,b,c}
|
|
{a:x, b:y, c:z} = obj
|
|
eq a, x
|
|
eq b, y
|
|
eq c, z
|
|
|
|
test "deep destructuring assignment with objects", ->
|
|
a={}; b={}; c={}; d={}
|
|
obj = {
|
|
a
|
|
b: {
|
|
'c': {
|
|
d: [
|
|
b
|
|
{e: c, f: d}
|
|
]
|
|
}
|
|
}
|
|
}
|
|
{a: w, 'b': {c: d: [x, {'f': z, e: y}]}} = obj
|
|
eq a, w
|
|
eq b, x
|
|
eq c, y
|
|
eq d, z
|
|
|
|
test "destructuring assignment with objects and splats", ->
|
|
a={}; b={}; c={}; d={}
|
|
obj = a: b: [a, b, c, d]
|
|
{a: b: [y, z...]} = obj
|
|
eq a, y
|
|
arrayEq [b,c,d], z
|
|
|
|
test "destructuring assignment against an expression", ->
|
|
a={}; b={}
|
|
[y, z] = if true then [a, b] else [b, a]
|
|
eq a, y
|
|
eq b, z
|
|
|
|
test "bracket insertion when necessary", ->
|
|
[a] = [0] ? [1]
|
|
eq a, 0
|
|
|
|
# for implicit destructuring assignment in comprehensions, see the comprehension tests
|
|
|
|
test "destructuring assignment with context (@) properties", ->
|
|
a={}; b={}; c={}; d={}; e={}
|
|
obj =
|
|
fn: () ->
|
|
local = [a, {b, c}, d, e]
|
|
[@a, {b: @b, c: @c}, @d, @e] = local
|
|
eq undefined, obj[key] for key in ['a','b','c','d','e']
|
|
obj.fn()
|
|
eq a, obj.a
|
|
eq b, obj.b
|
|
eq c, obj.c
|
|
eq d, obj.d
|
|
eq e, obj.e
|
|
|
|
test "#1024: destructure empty assignments to produce javascript-like results", ->
|
|
eq 2 * [] = 3 + 5, 16
|
|
|
|
test "#1005: invalid identifiers allowed on LHS of destructuring assignment", ->
|
|
disallowed = ['eval', 'arguments'].concat CoffeeScript.RESERVED
|
|
throws (-> CoffeeScript.compile "[#{disallowed.join ', '}] = x"), null, 'all disallowed'
|
|
throws (-> CoffeeScript.compile "[#{disallowed.join '..., '}...] = x"), null, 'all disallowed as splats'
|
|
t = tSplat = null
|
|
for v in disallowed when v isnt 'class' # `class` by itself is an expression
|
|
throws (-> CoffeeScript.compile t), null, t = "[#{v}] = x"
|
|
throws (-> CoffeeScript.compile tSplat), null, tSplat = "[#{v}...] = x"
|
|
doesNotThrow ->
|
|
for v in disallowed
|
|
CoffeeScript.compile "[a.#{v}] = x"
|
|
CoffeeScript.compile "[a.#{v}...] = x"
|
|
CoffeeScript.compile "[@#{v}] = x"
|
|
CoffeeScript.compile "[@#{v}...] = x"
|
|
|
|
test "#2055: destructuring assignment with `new`", ->
|
|
{length} = new Array
|
|
eq 0, length
|
|
|
|
test "#156: destructuring with expansion", ->
|
|
array = [1..5]
|
|
[first, ..., last] = array
|
|
eq 1, first
|
|
eq 5, last
|
|
[..., lastButOne, last] = array
|
|
eq 4, lastButOne
|
|
eq 5, last
|
|
[first, second, ..., last] = array
|
|
eq 2, second
|
|
[..., last] = 'strings as well -> x'
|
|
eq 'x', last
|
|
throws (-> CoffeeScript.compile "[1, ..., 3]"), null, "prohibit expansion outside of assignment"
|
|
throws (-> CoffeeScript.compile "[..., a, b...] = c"), null, "prohibit expansion and a splat"
|
|
throws (-> CoffeeScript.compile "[...] = c"), null, "prohibit lone expansion"
|
|
|
|
test "destructuring with dynamic keys", ->
|
|
{"#{'a'}": a, """#{'b'}""": b, c} = {a: 1, b: 2, c: 3}
|
|
eq 1, a
|
|
eq 2, b
|
|
eq 3, c
|
|
throws -> CoffeeScript.compile '{"#{a}"} = b'
|
|
|
|
test "simple array destructuring defaults", ->
|
|
[a = 1] = []
|
|
eq 1, a
|
|
[a = 2] = [undefined]
|
|
eq 2, a
|
|
[a = 3] = [null]
|
|
eq 3, a
|
|
[a = 4] = [0]
|
|
eq 0, a
|
|
arr = [a = 5]
|
|
eq 5, a
|
|
arrayEq [5], arr
|
|
|
|
test "simple object destructuring defaults", ->
|
|
{b = 1} = {}
|
|
eq b, 1
|
|
{b = 2} = {b: undefined}
|
|
eq b, 2
|
|
{b = 3} = {b: null}
|
|
eq b, 3
|
|
{b = 4} = {b: 0}
|
|
eq b, 0
|
|
|
|
{b: c = 1} = {}
|
|
eq c, 1
|
|
{b: c = 2} = {b: undefined}
|
|
eq c, 2
|
|
{b: c = 3} = {b: null}
|
|
eq c, 3
|
|
{b: c = 4} = {b: 0}
|
|
eq c, 0
|
|
|
|
test "multiple array destructuring defaults", ->
|
|
[a = 1, b = 2, c] = [null, 12, 13]
|
|
eq a, 1
|
|
eq b, 12
|
|
eq c, 13
|
|
[a, b = 2, c = 3] = [null, 12, 13]
|
|
eq a, null
|
|
eq b, 12
|
|
eq c, 13
|
|
[a = 1, b, c = 3] = [11, 12]
|
|
eq a, 11
|
|
eq b, 12
|
|
eq c, 3
|
|
|
|
test "multiple object destructuring defaults", ->
|
|
{a = 1, b: bb = 2, 'c': c = 3, "#{0}": d = 4} = {"#{'b'}": 12}
|
|
eq a, 1
|
|
eq bb, 12
|
|
eq c, 3
|
|
eq d, 4
|
|
|
|
test "array destructuring defaults with splats", ->
|
|
[..., a = 9] = []
|
|
eq a, 9
|
|
[..., b = 9] = [19]
|
|
eq b, 19
|
|
|
|
test "deep destructuring assignment with defaults", ->
|
|
[a, [{b = 1, c = 3}] = [c: 2]] = [0]
|
|
eq a, 0
|
|
eq b, 1
|
|
eq c, 2
|
|
|
|
test "destructuring assignment with context (@) properties and defaults", ->
|
|
a={}; b={}; c={}; d={}; e={}
|
|
obj =
|
|
fn: () ->
|
|
local = [a, {b, c: null}, d]
|
|
[@a, {b: @b = b, @c = c}, @d, @e = e] = local
|
|
eq undefined, obj[key] for key in ['a','b','c','d','e']
|
|
obj.fn()
|
|
eq a, obj.a
|
|
eq b, obj.b
|
|
eq c, obj.c
|
|
eq d, obj.d
|
|
eq e, obj.e
|
|
|
|
test "destructuring assignment with defaults single evaluation", ->
|
|
callCount = 0
|
|
fn = -> callCount++
|
|
[a = fn()] = []
|
|
eq 0, a
|
|
eq 1, callCount
|
|
[a = fn()] = [10]
|
|
eq 10, a
|
|
eq 1, callCount
|
|
{a = fn(), b: c = fn()} = {a: 20, b: null}
|
|
eq 20, a
|
|
eq c, 1
|
|
eq callCount, 2
|
|
|
|
|
|
# Existential Assignment
|
|
|
|
test "existential assignment", ->
|
|
nonce = {}
|
|
a = false
|
|
a ?= nonce
|
|
eq false, a
|
|
b = undefined
|
|
b ?= nonce
|
|
eq nonce, b
|
|
c = null
|
|
c ?= nonce
|
|
eq nonce, c
|
|
|
|
test "#1627: prohibit conditional assignment of undefined variables", ->
|
|
throws (-> CoffeeScript.compile "x ?= 10"), null, "prohibit (x ?= 10)"
|
|
throws (-> CoffeeScript.compile "x ||= 10"), null, "prohibit (x ||= 10)"
|
|
throws (-> CoffeeScript.compile "x or= 10"), null, "prohibit (x or= 10)"
|
|
throws (-> CoffeeScript.compile "do -> x ?= 10"), null, "prohibit (do -> x ?= 10)"
|
|
throws (-> CoffeeScript.compile "do -> x ||= 10"), null, "prohibit (do -> x ||= 10)"
|
|
throws (-> CoffeeScript.compile "do -> x or= 10"), null, "prohibit (do -> x or= 10)"
|
|
doesNotThrow (-> CoffeeScript.compile "x = null; x ?= 10"), "allow (x = null; x ?= 10)"
|
|
doesNotThrow (-> CoffeeScript.compile "x = null; x ||= 10"), "allow (x = null; x ||= 10)"
|
|
doesNotThrow (-> CoffeeScript.compile "x = null; x or= 10"), "allow (x = null; x or= 10)"
|
|
doesNotThrow (-> CoffeeScript.compile "x = null; do -> x ?= 10"), "allow (x = null; do -> x ?= 10)"
|
|
doesNotThrow (-> CoffeeScript.compile "x = null; do -> x ||= 10"), "allow (x = null; do -> x ||= 10)"
|
|
doesNotThrow (-> CoffeeScript.compile "x = null; do -> x or= 10"), "allow (x = null; do -> x or= 10)"
|
|
|
|
throws (-> CoffeeScript.compile "-> -> -> x ?= 10"), null, "prohibit (-> -> -> x ?= 10)"
|
|
doesNotThrow (-> CoffeeScript.compile "x = null; -> -> -> x ?= 10"), "allow (x = null; -> -> -> x ?= 10)"
|
|
|
|
test "more existential assignment", ->
|
|
global.temp ?= 0
|
|
eq global.temp, 0
|
|
global.temp or= 100
|
|
eq global.temp, 100
|
|
delete global.temp
|
|
|
|
test "#1348, #1216: existential assignment compilation", ->
|
|
nonce = {}
|
|
a = nonce
|
|
b = (a ?= 0)
|
|
eq nonce, b
|
|
#the first ?= compiles into a statement; the second ?= compiles to a ternary expression
|
|
eq a ?= b ?= 1, nonce
|
|
|
|
if a then a ?= 2 else a = 3
|
|
eq a, nonce
|
|
|
|
test "#1591, #1101: splatted expressions in destructuring assignment must be assignable", ->
|
|
nonce = {}
|
|
for nonref in ['', '""', '0', 'f()', '(->)'].concat CoffeeScript.RESERVED
|
|
eq nonce, (try CoffeeScript.compile "[#{nonref}...] = v" catch e then nonce)
|
|
|
|
test "#1643: splatted accesses in destructuring assignments should not be declared as variables", ->
|
|
nonce = {}
|
|
accesses = ['o.a', 'o["a"]', '(o.a)', '(o.a).a', '@o.a', 'C::a', 'C::', 'f().a', 'o?.a', 'o?.a.b', 'f?().a']
|
|
for access in accesses
|
|
for i,j in [1,2,3] #position can matter
|
|
code =
|
|
"""
|
|
nonce = {}; nonce2 = {}; nonce3 = {};
|
|
@o = o = new (class C then a:{}); f = -> o
|
|
[#{new Array(i).join('x,')}#{access}...] = [#{new Array(i).join('0,')}nonce, nonce2, nonce3]
|
|
unless #{access}[0] is nonce and #{access}[1] is nonce2 and #{access}[2] is nonce3 then throw new Error('[...]')
|
|
"""
|
|
eq nonce, unless (try CoffeeScript.run code, bare: true catch e then true) then nonce
|
|
# subpatterns like `[[a]...]` and `[{a}...]`
|
|
subpatterns = ['[sub, sub2, sub3]', '{0: sub, 1: sub2, 2: sub3}']
|
|
for subpattern in subpatterns
|
|
for i,j in [1,2,3]
|
|
code =
|
|
"""
|
|
nonce = {}; nonce2 = {}; nonce3 = {};
|
|
[#{new Array(i).join('x,')}#{subpattern}...] = [#{new Array(i).join('0,')}nonce, nonce2, nonce3]
|
|
unless sub is nonce and sub2 is nonce2 and sub3 is nonce3 then throw new Error('[sub...]')
|
|
"""
|
|
eq nonce, unless (try CoffeeScript.run code, bare: true catch e then true) then nonce
|
|
|
|
test "#1838: Regression with variable assignment", ->
|
|
name =
|
|
'dave'
|
|
|
|
eq name, 'dave'
|
|
|
|
test '#2211: splats in destructured parameters', ->
|
|
doesNotThrow -> CoffeeScript.compile '([a...]) ->'
|
|
doesNotThrow -> CoffeeScript.compile '([a...],b) ->'
|
|
doesNotThrow -> CoffeeScript.compile '([a...],[b...]) ->'
|
|
throws -> CoffeeScript.compile '([a...,[a...]]) ->'
|
|
doesNotThrow -> CoffeeScript.compile '([a...,[b...]]) ->'
|
|
|
|
test '#2213: invocations within destructured parameters', ->
|
|
throws -> CoffeeScript.compile '([a()])->'
|
|
throws -> CoffeeScript.compile '([a:b()])->'
|
|
throws -> CoffeeScript.compile '([a:b.c()])->'
|
|
throws -> CoffeeScript.compile '({a()})->'
|
|
throws -> CoffeeScript.compile '({a:b()})->'
|
|
throws -> CoffeeScript.compile '({a:b.c()})->'
|
|
|
|
test '#2532: compound assignment with terminator', ->
|
|
doesNotThrow -> CoffeeScript.compile """
|
|
a = "hello"
|
|
a +=
|
|
"
|
|
world
|
|
!
|
|
"
|
|
"""
|
|
|
|
test "#2613: parens on LHS of destructuring", ->
|
|
a = {}
|
|
[(a).b] = [1, 2, 3]
|
|
eq a.b, 1
|
|
|
|
test "#2181: conditional assignment as a subexpression", ->
|
|
a = false
|
|
false && a or= true
|
|
eq false, a
|
|
eq false, not a or= true
|
|
|
|
test "#1500: Assignment to variables similar to generated variables", ->
|
|
len = 0
|
|
x = ((results = null; n) for n in [1, 2, 3])
|
|
arrayEq [1, 2, 3], x
|
|
eq 0, len
|
|
|
|
for x in [1, 2, 3]
|
|
f = ->
|
|
i = 0
|
|
f()
|
|
eq 'undefined', typeof i
|
|
|
|
ref = 2
|
|
x = ref * 2 ? 1
|
|
eq x, 4
|
|
eq 'undefined', typeof ref1
|
|
|
|
x = {}
|
|
base = -> x
|
|
name = -1
|
|
base()[-name] ?= 2
|
|
eq x[1], 2
|
|
eq base(), x
|
|
eq name, -1
|
|
|
|
f = (@a, a) -> [@a, a]
|
|
arrayEq [1, 2], f.call scope = {}, 1, 2
|
|
eq 1, scope.a
|
|
|
|
try throw 'foo'
|
|
catch error
|
|
eq error, 'foo'
|
|
|
|
eq error, 'foo'
|
|
|
|
doesNotThrow -> CoffeeScript.compile '(@slice...) ->'
|
|
|
|
test "Assignment to variables similar to helper functions", ->
|
|
f = (slice...) -> slice
|
|
arrayEq [1, 2, 3], f 1, 2, 3
|
|
eq 'undefined', typeof slice1
|
|
|
|
class A
|
|
class B extends A
|
|
extend = 3
|
|
hasProp = 4
|
|
value: 5
|
|
method: (bind, bind1) => [bind, bind1, extend, hasProp, @value]
|
|
{method} = new B
|
|
arrayEq [1, 2, 3, 4, 5], method 1, 2
|
|
|
|
modulo = -1 %% 3
|
|
eq 2, modulo
|
|
|
|
indexOf = [1, 2, 3]
|
|
ok 2 in indexOf
|