Using postfix snippets on expressions containing '\\' results in it getting unescaped

[liquidev]

rust-analyzer version: 2022-03-28

rustc version: rustc 1.61.0-nightly (c5cf08d37 2022-03-30)

Example:

fn main() {
  let x = '\\'.ok|
}

(where | is the cursor)
Accepting the suggestion will result in this code:

fn main() {
  let x = Ok('\')|
}

which is invalid syntax.

It also seems that this happens with strings. Other escapes are intact, it's only \\ that gets mangled.

Also of note is that the escape may be nested in some deeper expression. For instance:

match x {
  true => '\\',
  false => 'a',
}.ok|

[Jesse-Bakker]

This is caused by the fact that \, $ and } are special tokens in a snippet, which should be escaped. RA returns these in the postfix completion snippet unescaped, causing them to disappear.

[logistic-bot]

This also happens in this situation, using rust-analyzer 46d7ee68f 2022-04-04 stable:

enum Test {
    Item1,
    Item2,
}

fn main() {
    let t = Test::Item2;

    match t {
        Test::Item1 => println!("\""),
    }
}

with the caret on the end of match t, and applying the suggestion fill match arms, results in the following code:

    match t {
        Test::Item1 => println!("""),
        Test::Item2 => todo!(),
    }