Module:No globals

English

Lua error in Module:TNT at line 158: Missing JsonConfig extension; Cannot load https://commons.wikimedia.org/wiki/Data:I18n/Shared Template Warning.tab.

Lua error in Module:TNT at line 158: Missing JsonConfig extension; Cannot load https://commons.wikimedia.org/wiki/Data:I18n/Shared Template Warning.tab.
Lua error in Module:TNT at line 158: Missing JsonConfig extension; Cannot load https://commons.wikimedia.org/wiki/Data:I18n/Shared Template Warning.tab.

<translate> This module is rated as [[<tvar name=1>Special:MyLanguage/Category:Modules for general use</tvar>|ready for general use]].</translate> <translate> It has reached a mature form and is thought to be bug-free and ready for use wherever appropriate.</translate> <translate> It is ready to mention on help pages and other resources as an option for new users to learn.</translate> <translate> To reduce server load and bad output, it should be improved by sandbox testing rather than repeated trial-and-error editing.</translate>

<translate> This module is [[<tvar name=1>Special:MyLanguage/Category:Modules subject to page protection</tvar>|subject to {{<tvar name=2>#if:</tvar>|cascading|page}} protection]].</translate> <translate> It is a highly visible module in use by a very large number of pages.</translate> <translate> Because vandalism or mistakes would affect many pages, and even trivial editing might cause substantial load on the servers, it is [[<tvar name=1>Special:MyLanguage/Project:Protected page</tvar>|protected]] from editing.</translate>

Usage

Include this module at the top of your code. An error will be raised any time your code tries to read or write to a non-local (undeclared) variable.

Tests

**Lua error in Module:TNT at line 158: Missing JsonConfig extension; Cannot load https://commons.wikimedia.org/wiki/Data:I18n/ModuleQuality.tab.**
Module:No globals	success: 1, error: 0, skipped: 0
Module:No globals/sandbox	success: 0, error: 1, skipped: 0

Lua error in Module:TNT at line 158: Missing JsonConfig extension; Cannot load https://commons.wikimedia.org/wiki/Data:I18n/ModuleQuality.tab.
Lua error in Module:TNT at line 158: Missing JsonConfig extension; Cannot load https://commons.wikimedia.org/wiki/Data:I18n/ModuleQuality.tab.

[[Category:Modules{{#translation:}}]]

local mt = getmetatable(_G) or {}
function mt.__index (t, k)
	if k ~= 'arg' then
		error('Tried to read nil global ' .. tostring(k), 2)
	end
	return nil
end
function mt.__newindex(t, k, v)
	if k ~= 'arg' then
		error('Tried to write global ' .. tostring(k), 2)
	end
	rawset(t, k, v)
end
setmetatable(_G, mt)