Module:No globals
Lua
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This module causes an error if any nil global is read or if any global is written to, with the exception of arg. To use, add require('Module:No globals')
to the top of the module using it. The arg variable is excluded because it is necessary for Scribunto's require function to work properly. (See the Scribunto source code here.)
Code
local mt = getmetatable(_G) or {}
local oldIndex = mt.__index or function() return nil end
mt.__index = function(t, k)
if k ~= 'name' and k ~= 'arg' then
error('Tried to read nil global ' .. tostring(k), 2)
end
return oldIndex(t, k)
end
local oldNewindex = mt.__newindex or rawset
function mt.__newindex(t, k, v)
if k ~= 'name' and k ~= 'arg' then
error('Tried to write global ' .. tostring(k), 2)
end
oldNewindex(t, k, v)
end
setmetatable(_G, mt)