`---@cast` annotation doesn't respect scope rules

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

The ---@cast annotation should respect Lua scoping rules.

Actual Behaviour

Let's consider:

--- @class foo
--- @field a number

--- @class bar
--- @field b string

--- @type { [integer]: foo|bar }
local array = {}

for i, instance in ipairs(array) do
	if instance.a then
                -- First if block
		--- @cast instance foo
	end

	if instance.b then
                -- Second if block
	end
end

In the first if block, we cast the instance to the foo type. When hovering over the instance variable in the second if block we can see its type is foo. It would be expected for its type to be bar since the ---@cast happened in different scope.

Reproduction steps

1. Copy-paste the given example code into your text editor.
2. Hover over the instance variable in the second if block.
3. See the error in the popup.

Additional Notes

No response

Log File

No response

首先，在 Visual Studio Code 擴充功能中使用提供的 Lua 範例重現問題，並檢查型別檢查如何處理兩個 if 區塊的作用域。完成條件是，對 foo 的 cast 僅在第一個區塊內套用，而第二個區塊中的執行個體保留適當的推斷型別，而不是 foo。