Diesel traits / methods are not resolved properly.

[oslac]

• rust-analyzer version: rust-analyzer version: 0.0.0 (427061da1 2022-06-19)
• rustc version: rustc 1.63.0-nightly (bb8c2f411 2022-06-19)
• relevant settings: None.

Issue: Rust-Analyzer fails to resolve some methods when using the Diesel ORM library. These would be the eq in diesel::ExpressionMethods and execute in diesel::RunQueryDsl as far as I can tell.

Example is available here: https://github.com/oslac/ra-diesel-traits

Expected: that RA properly resolves the traits / methods.

[bjorn3]

Does https://github.com/oslac/ra-diesel-traits/blob/fa1b4e62ba5abf4df7847f2fe8c1cf545e9faea8/src/schema.rs#L1 get expanded or does rust-analyzer show an error for it?

[oslac]

Does https://github.com/oslac/ra-diesel-traits/blob/fa1b4e62ba5abf4df7847f2fe8c1cf545e9faea8/src/schema.rs#L1 get expanded or does rust-analyzer show an error for it?

No errors from the schema.rs on my end. I can see the documentation pop up when I hover over the table! etc.

[bmisiak]

Database connectors are tricky for rust-analyzer. #6833 (comment)

[QuadraticKid]

Issue is still present on 2022-09-19 and nightly.
This issue was previously referenced, and is now merged; however it appears to have not been the solution.

Potentially related error log

[longsleep]

This problem seems to happen pretty much for every Diesel dsl lines.

        let mut result = users::table
            .select(User::as_select())
            .filter(users::username.eq(username))
            .load::<User>(&mut db)?;

The result variable type is {unknown}.

[Veykril]

This works with the latest master branch of diesel, cause was their proc-macros using 2015 name resolution which r-a does not support currently

[weiznich]

@Veykril It's fine to close these issues, but you probably want to link them to an root issue for 2015 style name resolution, because that's an actual bug/missing feature in rust-analyzer.

[QuadraticKid]

Issue still present on nightly, even building off of diesel's master branch. (Tests per diesel-rs/diesel 4b2ebca)

Tested with diesel's examples on schema dsl operations- the first operation resolves successfully (filter), however everything after that fails.

[weiznich]

@QuadraticKid The specific instances that are reported in this issue are resolved. What you likely see is another bug that surfaced after working around the first one. The type inference breakes as soon as a .filter()/.inner_join()/.left_join() appears in your query.

@Veykril Should I fill new issues for the broken case or do you want to reopen the existing ones?

[Veykril]

New one sounds better (with crosslinking for context maybe)

[weiznich]

I submitted #14607