Mixing #[rstest] and #[serial] breaks VS Code's IntelliSense with rust-analyzer

[mtilda]

Background

I am using the crates rstest and serial_test.

VS Code's IntelliSense stops working when I define a test function with both #[rstest] and #[serial].

IntelliSense is a VS Code feature (or rather a collection of features) that provide suggestions, information about symbols, and navigational tools.

The VS Code extension rust-analyzer provides support for the Rust language.

The root cause of this problem could be any one of the above mentioned technologies. Let me know if you think this issue does not belong on this repository.

Steps to reproduce

1. Install VS Code (I am on version 1.90.1)

2. Install the extension rust-analyzer (I am on version v0.3.2002)

3. Install Rust (I am on 1.78.0)

4. Use the command cargo init to create a new cargo package.

5. Add the necessary dependencies with the command cargo add rstest serial_test; or if you want the same versions as me, use the command cargo add rstest@0.21.0 serial_test@3.1.1

6. Open VS Code

7. Paste this in src/main.rs:

   mod tests;
   
   fn main() {
       println!("Hello, world!");
   }

8. Create src/tests.rs with the following content:

   #[cfg(test)]
   mod tests {
       use rstest::rstest;
       use serial_test::serial;
   
       #[rstest]
       fn test_a() {
           // IntelliSense works here
           let _example = vec![1,2,3];
       }
   
       #[test]
       #[serial]
       fn test_b() {
           // IntelliSense works here
           let _example = vec![1,2,3];
       }
   
       #[rstest]
       #[serial]
       fn test_c() {
           // IntelliSense does not work here
           let _example = vec![1,2,3];
       }
   }

Expected behavior

• Between _example and =, We should expect to see the inferred type Vec<i32>.
• Hover your mouse over the _example in each test function. We should expect to see a Peek.
• Type a . after vec![1,2,3] and before the ;. We should expect to see a drop down of suggestions (see screenshots).

Screenshots

[mtilda]

Cross-posted: la10736/rstest#262 (comment)

[palfrey]

Fixed by rust-lang/rust-analyzer#17462