No signature help returned at ':'

[gfreezy]

This test should pass.

#[test]
fn test_enum_in_nested_method_in_lambda() {
    check(
        r#"
enum A {
    A,
    B
}

fn bar(_: A) { }

fn main() {
    let foo = Foo;
    std::thread::spawn(move || { bar(A:$0) } );
}
"#,
        expect![[r#"
                fn bar(_: A)
                (<_: A>)
            "#]],
    );
}

Related ast is as below:

              [email protected]
                [email protected] "{"
                [email protected] "\n        "
                [email protected]
                  [email protected]
                    [email protected]
                      [email protected]
                        [email protected]
                          [email protected]
                            [email protected] "bar"
                    [email protected]
                      [email protected] "("
                      [email protected]
                        [email protected]
                          [email protected]
                            [email protected]
                              [email protected] "A"
                [email protected]
                  [email protected]
                    [email protected] ":"   <-------- here
                [email protected]
                  [email protected] ")"
                [email protected] "\n    "
                [email protected] "}"

[bjorn3]

bar(A:$0)

This is not valid rust syntax. You need to remove the :.

[lnicola]

Yeah, it works with both A and A::.

[gfreezy]

Screen.Recording.2021-09-07.at.2.02.06.PM.mov

[gfreezy]

The signature flips when typing A, A:, A::. It's disturbing.

It always show the outer function signature when the cursor is at an invalid syntax node instead of the current function.

[lnicola]

Interestingly, I don't get the thread::spawn docs:

signature.mp4

EDIT:

[gfreezy]

You need to trigger the bar signature first.
It seems to be the vscode behavior. When language server returns empty signature, vscode show the previous one.

input bar( => bar signature => input A: => spawn signature => input A:: => bar signature

[lnicola]

Nope, I still don't see it. But I do get your point.

[gfreezy]

rust-analyzer version: 3dae94bf2 2021-09-07 nightly

vscode

Version: 1.60.0
Commit: e7d7e9a9348e6a8cc8c03f877d39cb72e5dfb1ff
Date: 2021-09-01T10:54:53.442Z
Electron: 13.1.8
Chrome: 91.0.4472.164
Node.js: 14.16.0
V8: 9.1.269.39-electron.0
OS: Darwin x64 20.6.0

[lnicola]

Yeah, I'm on the same Code version. Does it happen with the code in your test?

[gfreezy]

Yeah, I'm on the same Code version. Does it happen with the code in your test?

enum A {
    A,
    B
}

fn bar(_: A) { }

fn main() {
    let foo = Foo;
    std::thread::spawn(move || { 
        bar(A:$0) 
    } // braces is needed 
    );
}

[lnicola]

Ah, right. My rustfmt ate those.

[Veykril]

Closed by #14128