LuaLS / LuaLS/lua-language-server
Inference failure when conditionally swapping variable?
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Description
Is the following expected? Why does inference fail at all?
```lua
local a, b = 5, 8
if a < b then
b, a = a, b
-- ^ Unknown: cannot infer type.
end
print("(" .. a .. ", " .. b .. ")")
```
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the conditional multiple-assignment example from the issue and inspect the inference path for `b, a = a, b`. Trace why the reassignment produces an unknown-type diagnostic, then verify that the snippet no longer reports the diagnostic while preserving the inferred types of `a` and `b`.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- lua
- Domain
- devtools
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Quiet
- Clarity
- Mostly clear
- Newbie friendliness
- 55/100