rust-lang / rust-lang/rust-analyzer
Generate function assist should generate async fn if return type is meant to impl Future
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A-assists
C-feature
S-actionable
- Dominant language
- Rust
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Description
I wrote this:
tokio::spawn(function_that_does_not_yet_exist());
and rust-analyzer generated
fn function_that_does_not_yet_exist() -> _ {
}
when I think it should have generated
async fn function_that_does_not_yet_exist() -> _ {
}
because tokio::spawn expects a T that implements Future, which a function call most commonly returns if the function is async.
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 example in the generate function assist, using tokio::spawn with a missing function call. Trace the assist's handling of the expected return type and verify that the generated declaration is async when the call is expected to implement Future; done when the behavior is covered by a regression test.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- rust
- Domain
- devtools
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100