luau/tests/conformance/closure.lua

-- This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
-- This file is based on Lua 5.x tests -- https://github.com/lua/lua/tree/master/testes
print "testing closures and coroutines"

local unpack = table.unpack

local A,B = 0,{g=10}
function f(x)
  local a = {}
  for i=1,1000 do
    local y = 0
    do
      a[i] = function () B.g = B.g+1; y = y+x; return y+A end
    end
  end
  local dummy = function () return a[A] end
  collectgarbage()
  A = 1; assert(dummy() == a[1]); A = 0;
  assert(a[1]() == x)
  assert(a[3]() == x)
  collectgarbage()
  assert(B.g == 12)
  return a
end

a = f(10)
-- force a GC in this level
local x = {[1] = {}}   -- to detect a GC
setmetatable(x, {__mode = 'kv'})
while x[1] do   -- repeat until GC
  local a = A..A..A..A  -- create garbage
  A = A+1
end
assert(a[1]() == 20+A)
assert(a[1]() == 30+A)
assert(a[2]() == 10+A)
collectgarbage()
assert(a[2]() == 20+A)
assert(a[2]() == 30+A)
assert(a[3]() == 20+A)
assert(a[8]() == 10+A)
assert(getmetatable(x).__mode == 'kv')
assert(B.g == 19)

-- testing closures with 'for' control variable
a = {}
for i=1,10 do
  a[i] = {set = function(x) i=x end, get = function () return i end}
  if i == 3 then break end
end
assert(a[4] == nil)
a[1].set(10)
assert(a[2].get() == 2)
a[2].set('a')
assert(a[3].get() == 3)
assert(a[2].get() == 'a')

a = {}
for i, k in pairs{'a', 'b'} do
  a[i] = {set = function(x, y) i=x; k=y end,
          get = function () return i, k end}
  if i == 2 then break end
end
a[1].set(10, 20)
local r,s = a[2].get()
assert(r == 2 and s == 'b')
r,s = a[1].get()
assert(r == 10 and s == 20)
a[2].set('a', 'b')
r,s = a[2].get()
assert(r == "a" and s == "b")


-- testing closures with 'for' control variable x break
for i=1,3 do
  f = function () return i end
  break
end
assert(f() == 1)

for k, v in pairs{"a", "b"} do
  f = function () return k, v end
  break
end
assert(({f()})[1] == 1)
assert(({f()})[2] == "a")


-- testing closure x break x return x errors

local b
function f(x)
  local first = 1
  while 1 do
    if x == 3 and not first then return end
    local a = 'xuxu'
    b = function (op, y)
          if op == 'set' then
            a = x+y
          else
            return a
          end
        end
    if x == 1 then do break end
    elseif x == 2 then return
    else if x ~= 3 then error() end
    end
    first = nil
  end
end

for i=1,3 do
  f(i)
  assert(b('get') == 'xuxu')
  b('set', 10); assert(b('get') == 10+i)
  b = nil
end

pcall(f, 4);
assert(b('get') == 'xuxu')
b('set', 10); assert(b('get') == 14)


local w
-- testing multi-level closure
function f(x)
  return function (y)
    return function (z) return w+x+y+z end
  end
end

y = f(10)
w = 1.345
assert(y(20)(30) == 60+w)

-- testing closures x repeat-until

local a = {}
local i = 1
repeat
  local x = i
  a[i] = function () i = x+1; return x end
until i > 10 or a[i]() ~= x
assert(i == 11 and a[1]() == 1 and a[3]() == 3 and i == 4)

print'+'


-- test for correctly closing upvalues in tail calls of vararg functions
local function t ()
  local function c(a,b) assert(a=="test" and b=="OK") end
  local function v(f, ...) c("test", f() ~= 1 and "FAILED" or "OK") end
  local x = 1
  return v(function() return x end)
end
t()


-- coroutine tests

local f

-- assert(coroutine.running() == nil)


-- tests for global environment
local _G = getfenv()

local function foo (a)
  setfenv(0, a)
  coroutine.yield(getfenv())
  assert(getfenv(0) == a)
  assert(getfenv(1) == _G)
  assert(getfenv(loadstring"") == a)
  return getfenv()
end

f = coroutine.wrap(foo)
local a = {}
assert(f(a) == _G)
local a,b = pcall(f)
assert(a and b == _G)


-- tests for multiple yield/resume arguments

local function eqtab (t1, t2)
  assert(table.getn(t1) == table.getn(t2))
  for i,v in ipairs(t1) do
    assert(t2[i] == v)
  end
end

_G.x = nil   -- declare x
function foo (a, ...)
  assert(coroutine.running() == f)
  assert(coroutine.status(f) == "running")
  local arg = {...}
  for i=1,table.getn(arg) do
    _G.x = {coroutine.yield(unpack(arg[i]))}
  end
  return unpack(a)
end

f = coroutine.create(foo)
assert(type(f) == "thread" and coroutine.status(f) == "suspended")
assert(string.find(tostring(f), "thread"))
local s,a,b,c,d
s,a,b,c,d = coroutine.resume(f, {1,2,3}, {}, {1}, {'a', 'b', 'c'})
assert(s and a == nil and coroutine.status(f) == "suspended")
s,a,b,c,d = coroutine.resume(f)
eqtab(_G.x, {})
assert(s and a == 1 and b == nil)
s,a,b,c,d = coroutine.resume(f, 1, 2, 3)
eqtab(_G.x, {1, 2, 3})
assert(s and a == 'a' and b == 'b' and c == 'c' and d == nil)
s,a,b,c,d = coroutine.resume(f, "xuxu")
eqtab(_G.x, {"xuxu"})
assert(s and a == 1 and b == 2 and c == 3 and d == nil)
assert(coroutine.status(f) == "dead")
s, a = coroutine.resume(f, "xuxu")
assert(not s and string.find(a, "dead") and coroutine.status(f) == "dead")


-- yields in tail calls
local function foo (i) return coroutine.yield(i) end
f = coroutine.wrap(function ()
  for i=1,10 do
    assert(foo(i) == _G.x)
  end
  return 'a'
end)
for i=1,10 do _G.x = i; assert(f(i) == i) end
_G.x = 'xuxu'; assert(f('xuxu') == 'a')

-- recursive
function pf (n, i)
  coroutine.yield(n)
  pf(n*i, i+1)
end

f = coroutine.wrap(pf)
local s=1
for i=1,10 do
  assert(f(1, 1) == s)
  s = s*i
end

-- sieve
function gen (n)
  return coroutine.wrap(function ()
    for i=2,n do coroutine.yield(i) end
  end)
end


function filter (p, g)
  return coroutine.wrap(function ()
    while 1 do
      local n = g()
      if n == nil then return end
      if n%p ~= 0 then coroutine.yield(n) end
    end
  end)
end

local x = gen(100)
local a = {}
while 1 do
  local n = x()
  if n == nil then break end
  table.insert(a, n)
  x = filter(n, x)
end

assert(table.getn(a) == 25 and a[table.getn(a)] == 97)


-- errors in coroutines
function foo ()
  -- assert(debug.getinfo(1).currentline == debug.getinfo(foo).linedefined + 1)
  -- assert(debug.getinfo(2).currentline == debug.getinfo(goo).linedefined)
  coroutine.yield(3)
  error("foo")
end

local fooerr = "closure.lua:284: foo"

function goo() foo() end
x = coroutine.wrap(goo)
assert(x() == 3)
local a,b = pcall(x)
assert(not a and b == fooerr)

x = coroutine.create(goo)
a,b = coroutine.resume(x)
assert(a and b == 3)
a,b = coroutine.resume(x)
assert(not a and b == fooerr and coroutine.status(x) == "dead")
a,b = coroutine.resume(x)
assert(not a and string.find(b, "dead") and coroutine.status(x) == "dead")


-- co-routines x for loop
function all (a, n, k)
  if k == 0 then coroutine.yield(a)
  else
    for i=1,n do
      a[k] = i
      all(a, n, k-1)
    end
  end
end

local a = 0
for t in coroutine.wrap(function () all({}, 5, 4) end) do
  a = a+1
end
assert(a == 5^4)


-- access to locals of collected coroutines
local C = {}; setmetatable(C, {__mode = "kv"})
local x = coroutine.wrap (function ()
            local a = 10
            local function f () a = a+10; return a end
            while true do
              a = a+1
              coroutine.yield(f)
            end
          end)

C[1] = x;

local f = x()
assert(f() == 21 and x()() == 32 and x() == f)
x = nil
collectgarbage()
-- assert(C[1] == nil)
assert(f() == 43 and f() == 53)


-- old bug: attempt to resume itself

function co_func (current_co)
  assert(coroutine.running() == current_co)
  assert(coroutine.resume(current_co) == false)
  assert(coroutine.resume(current_co) == false)
  return 10
end

local co = coroutine.create(co_func)
local a,b = coroutine.resume(co, co)
assert(a == true and b == 10)
assert(coroutine.resume(co, co) == false)
assert(coroutine.resume(co, co) == false)

-- access to locals of erroneous coroutines
local x = coroutine.create (function ()
            local a = 10
            _G.f = function () a=a+1; return a end
            error('x')
          end)

assert(not coroutine.resume(x))

-- overwrite previous position of local `a'
assert(not coroutine.resume(x, 1, 1, 1, 1, 1, 1, 1))
assert(_G.f() == 11)
assert(_G.f() == 12)

-- leaving a pending coroutine open
_X = coroutine.wrap(function ()
      local a = 10
      local x = function () a = a+1 end
      coroutine.yield()
    end)

_X()


-- coroutine environments
co = coroutine.create(function ()
       coroutine.yield(getfenv(0))
       return loadstring("return a")()
     end)

-- large closure size
do
  local a1, a2, a3, a4, a5, a6, a7, a8, a9, a0
  local b1, b2, b3, b4, b5, b6, b7, b8, b9, b0
  local c1, c2, c3, c4, c5, c6, c7, c8, c9, c0
  local d1, d2, d3, d4, d5, d6, d7, d8, d9, d0

  local f = function()
    return
      a1 + a2 + a3 + a4 + a5 + a6 + a7 + a8 + a9 + a0 +
      b1 + b2 + b3 + b4 + b5 + b6 + b7 + b8 + b9 + b0 +
      c1 + c2 + c3 + c4 + c5 + c6 + c7 + c8 + c9 + c0 +
      d1 + d2 + d3 + d4 + d5 + d6 + d7 + d8 + d9 + d0
  end
end

return 'OK'