Module pl.strict

Checks uses of undeclared global variables.

All global variables must be 'declared' through a regular assignment (even assigning nil will do) in a main chunk before being used anywhere or assigned to inside a function. Existing metatables __newindex and __index metamethods are respected.

You can set any table to have strict behaviour using strict.module. Creating a new module with strict.closed_module makes the module immune to monkey-patching, if you don't wish to encourage monkey business.

If the global PENLIGHT_NO_GLOBAL_STRICT is defined, then this module won't make the global environment strict - if you just want to explicitly set table strictness.

Functions

module ([name[, mod[, predeclared]]]) make an existing table strict.
make_all_strict (T) make all tables in a table strict.
closed_module (mod, name) make a new module table which is closed to further changes.


Functions

module ([name[, mod[, predeclared]]])
make an existing table strict.

Parameters:

  • name string name of table (optional)
  • mod table the table to protect - if nil then we'll return a new table (optional)
  • predeclared table
    • table of variables that are to be considered predeclared.
    (optional)

Returns:

    the given table, or a new table

Usage:

    local M = { hello = "world" }
strict.module ("Awesome_Module", M, {
  Lua = true,  -- defines allowed keys
})

assert(M.hello == "world")
assert(M.Lua == nil)       -- access allowed, but has no value yet
M.Lua = "Rocks"
assert(M.Lua == "Rocks")
M.not_allowed = "bad boy"  -- throws an error
make_all_strict (T)
make all tables in a table strict. So strict.make_all_strict(_G) prevents monkey-patching of any global table

Parameters:

  • T table the table containing the tables to protect. Table T itself will NOT be protected.
closed_module (mod, name)
make a new module table which is closed to further changes.

Parameters:

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