rust-lang / rust-lang/rust-analyzer

Inlining a method with an early return does not handle early return correctly.

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A-assists C-bug
Dominant language
Rust
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Description

rust-analyzer version: rust-analyzer version: 0.3.2319-standalone [/home/lennart/.vscode/extensions/rust-lang.rust-analyzer-0.3.2319-linux-x64/server/rust-analyzer]

rustc version: rustc 1.82.0 (f6e511eec 2024-10-15)

editor or extension: VSCode v0.3.2319

relevant settings: Base settings

repository link (if public, optional): https://github.com/pc2/sus-compiler

code snippet to reproduce:
Using the code action "Inline early_return" also inlines the return None statement unmodified, which does not match the original function's behavior

fn early_return() -> Option<()> {
    return None;
}
fn use_early_return() -> Option<()> {
    if early_return().is_none() {
        return Some(());
    }

    None
}

produces

fn use_early_return() -> Option<()> {
    if {
        return None;
    }.is_none() {
        return Some(());
    }

    None
}

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start from rust-analyzer's code action named Inline early_return and reproduce the issue with the Rust snippet provided. Compare the generated code's behavior with the original function; done means early returns preserve the original behavior and the regression is covered by a test.

Written by the indexing model from the issue text.

Assessment

Tech stack
rust
Domain
tooling
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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