1 files changed, 60 insertions, 0 deletions
diff --git a/test/lua/busted/compatibility.lua b/test/lua/busted/compatibility.lua
new file mode 100644
index 000000000..7837656fb
--- /dev/null
+++ b/test/lua/busted/compatibility.lua
@@ -0,0 +1,60 @@
+return {
+  getfenv = getfenv or function(f)
+    f = (type(f) == 'function' and f or debug.getinfo(f + 1, 'f').func)
+    local name, value
+    local up = 0
+
+    repeat
+      up = up + 1
+      name, value = debug.getupvalue(f, up)
+    until name == '_ENV' or name == nil
+
+    return value
+  end,
+
+  setfenv = setfenv or function(f, t)
+    f = (type(f) == 'function' and f or debug.getinfo(f + 1, 'f').func)
+    local name
+    local up = 0
+
+    repeat
+      up = up + 1
+      name = debug.getupvalue(f, up)
+    until name == '_ENV' or name == nil
+
+    if name then
+      debug.upvaluejoin(f, up, function() return name end, 1)
+      debug.setupvalue(f, up, t)
+    end
+
+    if f ~= 0 then return f end
+  end,
+
+  unpack = table.unpack or unpack,
+
+  osexit = function(code, close)
+    if close and _VERSION == 'Lua 5.1' then
+      -- From Lua 5.1 manual:
+      -- > The userdata itself is freed only in the next
+      -- > garbage-collection cycle.
+      -- Call collectgarbage() while collectgarbage('count')
+      -- changes + 3 times, at least 3 times,
+      -- at max 100 times (to prevent infinite loop).
+      local times_const = 0
+      for i = 1, 100 do
+        local count_before = collectgarbage("count")
+        collectgarbage()
+        local count_after = collectgarbage("count")
+        if count_after == count_before then
+          times_const = times_const + 1
+          if times_const > 3 then
+            break
+          end
+        else
+          times_const = 0
+        end
+      end
+    end
+    os.exit(code, close)
+  end,
+}