moonpie.utility

ensureKey(tbl, key, default)

Makes sure that a table contains a key with a default value. Useful for state management in the store to make sure that values exist

isCallable(val)

Returns true if the parameter is either a function or a table with a metatable that implements __call.

local utility = require "moonpie.utility"
utility.isCallable(function() end) -- true
utility.isCallable({}) -- false
utility.isCallable(setmetatable({}, { __call = function() end })) -- true

swapFunction(tbl, functionName, override)

Replaces a table function with a new routine. This is most useful for testing scenarios to mock an API. :revert() can be used to unwind the swapped function.

local utility = require "moonpie.utility
local tbl = { f = function() end }
local new = function() end
utility.swapFunction(tbl, "f", new)
tbl:f() -- calls new(tbl)