Function trailing_commas

libs/@local/hashql/syntax-jexpr/src/parser/array/error.rs:147–162

(spans: &[SpanId])

                                   `[item1, item2]` instead of `[item1, item2,]`";

pub(crate) fn trailing_commas(spans: &[SpanId]) -> ArrayDiagnostic {
    let (&first, rest) = spans.split_first().expect("spans must be non-empty");

    let mut diagnostic = Diagnostic::new(ArrayDiagnosticCategory::TrailingComma, Critical::ERROR)
        .primary(Label::new(first, "Remove this trailing comma"));

    for &span in rest {
        diagnostic
            .labels
            .push(Label::new(span, "... and this trailing comma"));
    }

    diagnostic.add_message(Message::help(TRAILING_COMMA_HELP));

    diagnostic
}

const LEADING_COMMA_HELP: &str =
    "J-Expr does not support leading commas in arrays. Use `[item1, item2]` format.";