rust-tools.nvim RustHoverActions doesn't work for async main functions and tests

RustHoverActions doesn't work for async main functions and tests

Open poljar opened this issue 2 years ago • 4 comments

Tokio, and other async runtimes, tend to have nice macros to use async functions as a main function or as a test. Async functions annotated with #[tokio::main] and #[tokio::test] can be used normally as the main function, and test functions respectively, without any additional setup.

Those functions can be run and debugged with the vim.lsp.codelens.refresh() and vim.lsp.codelens.run() lua methods just fine:

However, RustHoverActions doesn't display anything sensible:

RustHoverActions works fine if we convert the method back to a non-async one and do the async plumbing #[tokio::main] does for us manually:

The minimal reproducer is:

use std::time::Duration;

#[tokio::main]
async fn main() {
    println!("Sleeping, world!");
    tokio::time::sleep(Duration::from_secs(10)).await;
    println!("Hello, world!");
}

While the working non-async variant is:

use std::time::Duration;

fn main() -> anyhow::Result<()> {
    let runtime = tokio::runtime::Runtime::new()?;

    runtime.block_on(async {
        println!("Sleeping, world!");
        tokio::time::sleep(Duration::from_secs(10)).await;
        println!("Hello, world!");
    });

    Ok(())
}

Both work with the following Cargo.toml file:

[package]
name = "test-tokio-rust-tools"
version = "0.1.0"
edition = "2021"

[dependencies]
anyhow = "1"
tokio = { version = "1.20.1", features = ["rt-multi-thread", "macros", "time"] }