When trying to define a type using the type checker’s typeof() method, methods inherited through __index that assert self’s type as the type returned from typeof(), aren’t recognized.
Where it happens: Happens in Studio only
When it happens: I first noticed it August 16 2022 at 11:30 PM AST
Reproduction instructions:
This should reproduce the issue 100% of the time.
This happens in both nonstrict and strict modes, however only in strict does it emit a warning.
To reproduce, write the following in some LuaSourceContainer:
--!strict
local module = {}
module.__index = module
function module:method()
self = self :: ModuleType
end
function module.new()
return setmetatable({}, module)
end
export type ModuleType = typeof(module.new())
local m = module.new()
m:method()
Now, a warning will appear at m:method() telling you type “ModuleType” does not have key “method” despite inheriting the method through the __index metamethod. Lua does not error either.
This warning also disappears once you remove the self = self :: ModuleType line from the module:method() function.
The method does appear in the auto complete.