# Assignment # ---------- # * Assignment # * Compound Assignment # * Destructuring Assignment # * Context Property (@) Assignment # * Existential Assignment (?=) 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) test "compound assignments should not declare", -> # TODO: make description more clear # TODO: remove reference to Math eq Math, (-> Math or= 0)() # 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 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 # 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", -> 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", -> eq 2 * [] = 3 + 5, 16 # 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 d ?= nonce eq nonce, d test "#1348, #1216: existential assignment comilation", -> nonce = {} a = nonce b = (a ?= 0) eq nonce, b