Union table|class doesn't accept a generic table and only accepts a class instance (causing false missing-fields diagnostic)

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Windows

What is the issue affecting?

Type Checking, Diagnostics/Syntax Checking

Expected Behaviour

When a function is declared as accepting both table and a custom class type, it should accept getting passed a generic table.

Actual Behaviour

LLS insists on a table matching the class being passed (with all the fields set) and reports the missing-fields diagnostic when passing a generic table.

Reproduction steps

LLS definition file contains the following:

---@meta

---@class TestClass
---@field TestField number A test field in test class
TestClass = {}

-- TestFunction1
---@param generic_table_or_testclass_instance table|TestClass
function TestFunction1(generic_table_or_testclass_instance) end

-- TestFunction2
---@param generic_table table
---@param testclass_instance TestClass
---@overload fun(generic_table: table)
---@overload fun(testclass_instance: TestClass)
function TestFunction2(generic_table, testclass_instance) end

-- TestFunction3
---@param generic_table table
function TestFunction3(generic_table) end

-- TestFunction3
---@param testclass_instance TestClass
function TestFunction3(testclass_instance) end

And then a lua code file contains a call to either test function like

TestFunction1({1,2,3})
TestFunction2({1,2,3})
TestFunction3({1,2,3})

LLS reports Missing required fields in type ``TestClass``: ``TestField`` Lua Diagnostics.(missing-fields) for all 3 calls. Instead it should accept the table as input parameter for the 3 functions.

Additional Notes

No response

Log File

No response

Commencez par Lua et les annotations de types de la reproduction, puis suivez le chemin de vérification des types qui produit le diagnostic de champs manquants pour les paramètres d’union et de surcharge. C’est terminé lorsque les tables génériques sont acceptées pour les trois appels sans signaler l’absence de TestClass.TestField ; aucun fichier source ni test n’est nommé dans l’issue.