Casting an otherwise unused variable in a block preserves the cast outside of block

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

Any casts inside a block should not be maintained once leaving that block.

Actual Behaviour

Type cast is maintained even after the block in which the variable was cast if and only if the variable was not used in that block.

Reproduction steps

This is incorrect:

---@type number|string
local i
if true then --can be `false` or any other logical
  ---@cast i number
  local _ = 0 --not referencing variable `i` that was cast above
end
local j = i --type of j is `number`, should be `number|string`

This is correct:

---@type number|string
local i
if true then --can be `false` or any other logical
  ---@cast i number
  local _ = i -- referencing variable `i` that was cast above
end
local j = i --type of j is `number|string`

Additional Notes

No response

Log File

No response

通过 Visual Studio Code 扩展重现两个 Lua 代码片段，并比较块之后 j 的推断类型。跟踪 cast 变量未使用时 @cast 处理的类型检查路径，然后验证 cast 不会保留到块之外，同时块内引用的情况仍然正确。