BatsAndPray/lib/middleclass/spec/metamethods_spec.lua

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2020-09-19 01:53:57 -05:00
local class = require 'middleclass'
local function is_lua_5_2_compatible()
return type(rawlen) == 'function'
end
local function is_lua_5_3_compatible()
return type(string.unpack) == 'function'
end
if is_lua_5_2_compatible() then
require 'spec/metamethods_lua_5_2'
end
if is_lua_5_3_compatible() then
require 'spec.metamethods_lua_5_3'
end
describe('Metamethods', function()
describe('Custom Metamethods', function()
local Vector, v, w
before_each(function()
Vector= class('Vector')
function Vector.initialize(a,x,y,z) a.x, a.y, a.z = x,y,z end
function Vector.__tostring(a) return a.class.name .. '[' .. a.x .. ',' .. a.y .. ',' .. a.z .. ']' end
function Vector.__eq(a,b) return a.x==b.x and a.y==b.y and a.z==b.z end
function Vector.__lt(a,b) return a() < b() end
function Vector.__le(a,b) return a() <= b() end
function Vector.__add(a,b) return a.class:new(a.x+b.x, a.y+b.y ,a.z+b.z) end
function Vector.__sub(a,b) return a.class:new(a.x-b.x, a.y-b.y, a.z-b.z) end
function Vector.__div(a,s) return a.class:new(a.x/s, a.y/s, a.z/s) end
function Vector.__unm(a) return a.class:new(-a.x, -a.y, -a.z) end
function Vector.__concat(a,b) return a.x*b.x+a.y*b.y+a.z*b.z end
function Vector.__call(a) return math.sqrt(a.x*a.x+a.y*a.y+a.z*a.z) end
function Vector.__pow(a,b)
return a.class:new(a.y*b.z-a.z*b.y,a.z*b.x-a.x*b.z,a.x*b.y-a.y*b.x)
end
function Vector.__mul(a,b)
if type(b)=="number" then return a.class:new(a.x*b, a.y*b, a.z*b) end
if type(a)=="number" then return b.class:new(a*b.x, a*b.y, a*b.z) end
end
Vector.__metatable = "metatable of a vector"
Vector.__mode = "k"
v = Vector:new(1,2,3)
w = Vector:new(2,4,6)
end)
it('implements __tostring', function()
assert.equal(tostring(v), "Vector[1,2,3]")
end)
it('implements __eq', function()
assert.equal(v, v)
end)
it('implements __lt', function()
assert.is_true(v < w)
end)
it('implements __le', function()
assert.is_true(v <= w)
end)
it('implements __add', function()
assert.equal(v+w, Vector(3,6,9))
end)
it('implements __sub', function()
assert.equal(w-v, Vector(1,2,3))
end)
it('implements __div', function()
assert.equal(w/2, Vector(1,2,3))
end)
it('implements __concat', function()
assert.equal(v..w, 28)
end)
it('implements __call', function()
assert.equal(v(), math.sqrt(14))
end)
it('implements __pow', function()
assert.equal(v^w, Vector(0,0,0))
end)
it('implements __mul', function()
assert.equal(4*v, Vector(4,8,12))
end)
it('implements __metatable', function()
assert.equal("metatable of a vector", getmetatable(v))
end)
it('implements __mode', function()
v[{}] = true
collectgarbage()
for k in pairs(v) do assert.not_table(k) end
end)
--[[
it('implements __index', function()
assert.equal(b[1], 3)
end)
--]]
describe('Inherited Metamethods', function()
local Vector2, v2, w2
before_each(function()
Vector2= class('Vector2', Vector)
function Vector2:initialize(x,y,z) Vector.initialize(self,x,y,z) end
v2 = Vector2:new(1,2,3)
w2 = Vector2:new(2,4,6)
end)
it('implements __tostring', function()
assert.equal(tostring(v2), "Vector2[1,2,3]")
end)
it('implements __eq', function()
assert.equal(v2, v2)
end)
it('implements __lt', function()
assert.is_true(v2 < w2)
end)
it('implements __le', function()
assert.is_true(v2 <= w2)
end)
it('implements __add', function()
assert.equal(v2+w2, Vector2(3,6,9))
end)
it('implements __sub', function()
assert.equal(w2-v2, Vector2(1,2,3))
end)
it('implements __div', function()
assert.equal(w2/2, Vector2(1,2,3))
end)
it('implements __concat', function()
assert.equal(v2..w2, 28)
end)
it('implements __call', function()
assert.equal(v2(), math.sqrt(14))
end)
it('implements __pow', function()
assert.equal(v2^w2, Vector2(0,0,0))
end)
it('implements __mul', function()
assert.equal(4*v2, Vector2(4,8,12))
end)
it('implements __metatable', function()
assert.equal("metatable of a vector", getmetatable(v2))
end)
it('implements __mode', function()
v2[{}] = true
collectgarbage()
for k in pairs(v2) do assert.not_table(k) end
end)
it('allows inheriting further', function()
local Vector3 = class('Vector3', Vector2)
local v3 = Vector3(1,2,3)
local w3 = Vector3(3,4,5)
assert.equal(v3+w3, Vector3(4,6,8))
end)
describe('Updates', function()
it('overrides __add', function()
Vector2.__add = function(a, b) return Vector.__add(a, b)/2 end
assert.equal(v2+w2, Vector2(1.5,3,4.5))
end)
it('updates __add', function()
Vector.__add = Vector.__sub
assert.equal(v2+w2, Vector2(-1,-2,-3))
end)
it('does not update __add after overriding', function()
Vector2.__add = function(a, b) return Vector.__add(a, b)/2 end
Vector.__add = Vector.__sub
assert.equal(v2+w2, Vector2(-0.5,-1,-1.5))
end)
it('reverts __add override', function()
Vector2.__add = function(a, b) return Vector.__add(a, b)/2 end
Vector2.__add = nil
assert.equal(v2+w2, Vector2(3,6,9))
end)
end)
end)
end)
describe('Custom __index and __newindex', function()
describe('Tables', function()
local Proxy, fallback, p
before_each(function()
Proxy = class('Proxy')
fallback = {foo = 'bar', common = 'fallback'}
Proxy.__index = fallback
Proxy.__newindex = fallback
Proxy.common = 'class'
p = Proxy()
end)
it('uses __index', function()
assert.equal(p.foo, 'bar')
end)
it('does not use __index when field exists in class', function()
assert.equal(p.common, 'class')
end)
it('uses __newindex', function()
p.key = 'value'
assert.equal(fallback.key, 'value')
end)
it('uses __newindex when field exists in class', function()
p.common = 'value'
assert.equal(p.common, 'class')
assert.equal(Proxy.common, 'class')
assert.equal(fallback.common, 'value')
end)
end)
describe('Functions', function()
local Namespace, Rectangle, r
before_each(function()
Namespace = class('Namespace')
function Namespace:__index(name)
local getter = self.class[name.."Getter"]
if getter then return getter(self) end
end
function Namespace:__newindex(name, value)
local setter = self.class[name.."Setter"]
if setter then setter(self, value) else rawset(self, name, value) end
end
Rectangle = class('Rectangle', Namespace)
function Rectangle:initialize(x, y, scale)
self._scale, self.x, self.y = 1, x, y
self.scale = scale
end
function Rectangle:scaleGetter() return self._scale end
function Rectangle:scaleSetter(v)
self.x = self.x*v/self._scale
self.y = self.y*v/self._scale
self._scale = v
end
function Rectangle:areaGetter() return self.x * self.y end
r = Rectangle(3, 4, 2)
end)
it('uses setter', function()
assert.equal(r.x, 6)
assert.equal(r.y, 8)
r.scale = 3
assert.equal(r.x, 9)
assert.equal(r.y, 12)
end)
it('uses getters', function()
assert.equal(r.scale, 2)
assert.equal(r.area, 48)
end)
it('updates inherited __index', function()
function Namespace.__index() return 42 end
assert.equal(r.area, 42)
function Rectangle.__index() return 24 end
assert.equal(r.area, 24)
function Namespace.__index() return 96 end
assert.equal(r.area, 24)
Rectangle.__index = nil
assert.equal(r.area, 96)
end)
end)
end)
describe('Default Metamethods', function()
local Peter, peter
before_each(function()
Peter = class('Peter')
peter = Peter()
end)
describe('A Class', function()
it('has a call metamethod properly set', function()
assert.is_true(peter:isInstanceOf(Peter))
end)
it('has a tostring metamethod properly set', function()
assert.equal(tostring(Peter), 'class Peter')
end)
end)
describe('An instance', function()
it('has a tostring metamethod, returning a different result from Object.__tostring', function()
assert.equal(tostring(peter), 'instance of class Peter')
end)
end)
end)
end)