Enum type is lost when given as union

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Windows WSL

What is the issue affecting?

Type Checking

Expected Behaviour

A parameter of union of enum entries should accept those entries.

Actual Behaviour

---Command constants.
---
---@enum CMD
CMD = {
	---@type 40
	REPAIR = nil,

	---@type 90
	RECLAIM = nil,

	---@type 110
	RESTORE = nil,

	---@type 125
	RESURRECT = nil,

	---@type 130
	CAPTURE = nil,
}

---Called when a construction unit wants to "use his nano beams".
---
---@param unitID integer
---@param unitDefID integer
---@param action
---  | -1 # Build
---  | CMD.REPAIR # Repair
---  | CMD.RECLAIM # Reclaim
---  | CMD.RESTORE # Restore
---  | CMD.RESURRECT # Resurrect
---  | CMD.CAPTURE # Capture
---@return boolean actionAllowed
function SyncedCallins:AllowBuilderHoldFire(unitID, unitDefID, action) end

local x = nil ---@type SyncedCallins
local y = x:AllowBuilderHoldFire(5, 3, CMD.REPAIR)

The enum type is being resolved to 40 and losing information about it being an enum.

[{
	"resource": "/home/rhys/spring/rts/Lua/library/generated/library.lua",
	"owner": "_generated_diagnostic_collection_name_#1",
	"code": "param-type-mismatch",
	"severity": 4,
	"message": "Cannot assign `40` to parameter `-1|CMD.CAPTURE|CMD.RECLAIM|CMD.REPAIR|CMD.RESTORE...(+1)`.\n- `40` cannot match `-1|CMD.CAPTURE|CMD.RECLAIM|CMD.REPAIR|CMD.RESTORE...(+1)`\n- `40` cannot match any subtypes in `-1|CMD.CAPTURE|CMD.RECLAIM|CMD.REPAIR|CMD.RESTORE...(+1)`\n- Type `40` cannot match `CMD.CAPTURE`\n- Type `number` cannot match `CMD.CAPTURE`\n- Type `40` cannot match `CMD.RESURRECT`\n- Type `number` cannot match `CMD.RESURRECT`\n- Type `40` cannot match `CMD.RESTORE`\n- Type `number` cannot match `CMD.RESTORE`\n- Type `40` cannot match `CMD.RECLAIM`\n- Type `number` cannot match `CMD.RECLAIM`\n- Type `40` cannot match `CMD.REPAIR`\n- Type `number` cannot match `CMD.REPAIR`\n- Literal `40` cannot match integer `-1`",
	"source": "Lua Diagnostics.",
	"startLineNumber": 3090,
	"startColumn": 40,
	"endLineNumber": 3090,
	"endColumn": 50
}]

Reproduction steps

Paste code example above into VSCode.

Additional Notes

No response

Log File

No response

使用 issue 中的 Lua 示例在 Visual Studio Code 中复现该诊断，然后检查针对 generated/library.lua 报告的类型检查路径。当 CMD.REPAIR 和其他枚举成员能够作为文档所述 union 的参数被接受，且没有 param-type-mismatch 诊断时，此更改即完成。