rust-analyzer/crates/ide-diagnostics/src/handlers/undeclared_label.rs

use crate::{Diagnostic, DiagnosticsContext};

// Diagnostic: undeclared-label
pub(crate) fn undeclared_label(
    ctx: &DiagnosticsContext<'_>,
    d: &hir::UndeclaredLabel,
) -> Diagnostic {
    let name = &d.name;
    Diagnostic::new(
        "undeclared-label",
        format!("use of undeclared label `{name}`"),
        ctx.sema.diagnostics_display_range(d.node.clone().map(|it| it.into())).range,
    )
}

#[cfg(test)]
mod tests {
    use crate::tests::check_diagnostics;

    #[test]
    fn smoke_test() {
        check_diagnostics(
            r#"
fn foo() {
    break 'a;
        //^^ error: use of undeclared label `'a`
    continue 'a;
           //^^ error: use of undeclared label `'a`
}
"#,
        );
    }

    #[test]
    fn try_operator_desugar_works() {
        check_diagnostics(
            r#"
//- minicore: option, try
fn foo() {
    None?;
}
"#,
        );
        check_diagnostics(
            r#"
//- minicore: option, try, future
async fn foo() {
    None?;
}
"#,
        );
        check_diagnostics(
            r#"
//- minicore: option, try, future, fn
async fn foo() {
    || None?;
}
"#,
        );
    }
}