[Bug] Union when combine table with classified type. Attributes of table are hidden.

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

Expected Behaviour

local data = {}
function data:set(k, v)
  rawset(self, k, v)
end

--- @class Person
local Person = {}
function Person:speak() end

--- @generic T
--- @param t T
--- @return T|Person
function merge(t, p)
-- ...
end

local m = merge(data, Person)
m:set -- Completion should show [set(k, v)] 应该提示 set(k,v)，对应 data:set(k,v)

Actual Behaviour

local data = {}
function data:set()
end

--- @class Person
local Person = {}
function Person:speak() end

--- @generic T
--- @param t T
--- @return T|Person
function merge(t, p)
-- ...
end

local m = merge(data, Person)
m:set -- doesn't complete this method, 没显示，只有一个单纯的文本补全

But .... 但是... 你换成 {} 而不去声明 @class Person 倒是会有的

local data = {}
function data:set()
end

local Person = {}
function Person:speak() end

--- @generic T
--- @param t T
--- @return T|{speak: function}  !!!!! See here !!! 看这里，换成纯粹的 table 到会有  
function merge(t, p)
-- ...
end

local m = merge(data, Person)
m:set -- Completion is right and show [set(k,v)]，补全正常显示

I guess the @class Person hides the origin type.

我认为 @class Person 把原本的 data 表 属性都给给覆盖掉了。

而且还有个诡异现象，如果 data 给一些 默认值：

local data = {value = 123}

不管哪种方式 都能把 默认属性 给补出来。

这很明显这个 luals 的 union 组合有 bug！

Reproduction steps

See obove

Additional Notes

No response

Log File

No response

Reproduzca el problema en la extensión de Visual Studio Code utilizando los ejemplos de Lua proporcionados y compare la unión con @class Person con el tipo de tabla inline. Rastree la comprobación de tipos y el manejo de la completion para el resultado de merge cuando se consulta m:set. Se considera terminado cuando la completion incluye data:set y conserva miembros de Person como speak.