extract_format_args assist escapes `\` character in `\n` etc.

[kartva]

rust-analyzer version: rust-analyzer version: 0.3.1860-standalone

rustc version: rustc 1.76.0 (07dca489a 2024-02-04)

code snippet to reproduce:
Add the following test in rust-analyzer/crates/ide-assists/src/handlers/extract_expressions_from_format_string.rs

    #[test]
    fn escaped_literals() {
        check_assist(
            extract_expressions_from_format_string,
            &add_macro_decl(
                r#"
fn main() {
    print!("\n {x + 1}$0");
}
            "#,
            ),
            &add_macro_decl(
                r#"
fn main() {
    print!("\n {}"$0, x + 1);
}
            "#,
            ),
        );
    }

fails and instead produces

fn main() {
    print!("\\n {}"$0, x + 1);
}

[Veykril]

not sure if this is related to your changes or not but it might so pinging @DropDemBits

[DropDemBits]

Looks like extract_expressions_from_format_string is using snippet stuff but not insert_snippet or replace_snippet, so I didn't catch it as part of the assists to migrate to the structured snippet API.

It also looks like parse_format_exprs is the one escaping the \:

rust-analyzer/crates/ide-db/src/syntax_helpers/format_string_exprs.rs

Lines 82 to 84 in 9f14343

	if matches!(chr, '\\' | '$') {
	output.push('\\');
	}

[DropDemBits]

I have some time today, so I'll take this up.
@rustbot claim