diff --git a/scripts/layers.lua b/scripts/layers.lua
index ca0edc9c5..344fe8f7f 100644
--- a/scripts/layers.lua
+++ b/scripts/layers.lua
@@ -1,3 +1,4 @@
+-- Copyright (C) 2019  Igara Studio S.A.
 -- Copyright (C) 2018  David Capello
 --
 -- This file is released under the terms of the MIT license.
@@ -28,3 +29,80 @@ do
   assert(s.layers[1] == a)
   assert(s.layers[2] == c)
 end
+
+-- Test groups
+
+do
+  local s = Sprite(32, 64)
+  local l = s.layers[1]
+  assert(#s.layers == 1)
+  local g = s:newGroup()
+  assert(#s.layers == 2)
+  assert(l.parent == s)
+  assert(g.parent == s)
+  assert(s.layers[1] == l)
+  assert(s.layers[2] == g)
+
+  l.parent = g
+  assert(g.parent == s)
+  assert(l.parent == g)
+
+  assert(#s.layers == 1)
+  assert(s.layers[1] == g)
+  assert(#s.layers[1].layers == 1)
+  assert(s.layers[1].layers[1] == l)
+end
+
+do
+  local s = Sprite(4, 4)
+  -- 4 layers
+  local a = s.layers[1]    a.name = "a"
+  local b = s:newLayer()   b.name = "b"
+  local c = s:newLayer()   c.name = "c"
+  local d = s:newLayer()   d.name = "d"
+  -- 3 groups
+  local e = s:newGroup()   e.name = "e"
+  local f = s:newGroup()   f.name = "f"
+  local g = s:newGroup()   g.name = "g"
+
+  e.parent = f
+  a.parent = f
+  b.parent = f
+  c.parent = g
+  d.parent = g
+
+  assert(#s.layers == 2)
+  assert(s.layers[1] == f)
+  assert(s.layers[2] == g)
+  assert(s.layers["f"] == f)
+  assert(s.layers["g"] == g)
+  assert(f.stackIndex == 1)
+  assert(g.stackIndex == 2)
+
+  assert(#f.layers == 3)
+  assert(f.layers[1] == e)
+  assert(f.layers[2] == a)
+  assert(f.layers[3] == b)
+  assert(f.layers["e"] == e)
+  assert(f.layers["a"] == a)
+  assert(f.layers["b"] == b)
+  assert(e.stackIndex == 1)
+  assert(a.stackIndex == 2)
+  assert(b.stackIndex == 3)
+
+  assert(#g.layers == 2)
+  assert(g.layers[1] == c)
+  assert(g.layers[2] == d)
+  assert(g.layers["c"] == c)
+  assert(g.layers["d"] == d)
+  assert(c.stackIndex == 1)
+  assert(d.stackIndex == 2)
+
+  d.stackIndex = 1
+  assert(d.stackIndex == 1)
+  assert(c.stackIndex == 2)
+
+  d.stackIndex = 3
+  assert(c.stackIndex == 1)
+  assert(d.stackIndex == 2)
+end