swc-project/swc · error · Error

Expected Ident

Error message

Expected Ident

What it means

Fired while parsing a CustomIdent: the current token was not an Ident, so no CSS-wide-keyword-excluded custom identifier could be produced. The `if !is!(self, Ident)` check is a validation guard; input at fault is a context expecting a custom ident (e.g. a counter style name, keyframes name) that receives a number, string, or other token.

Source

Thrown at crates/swc_css_parser/src/parser/values_and_units/mod.rs:1829

                value,
                raw: Some(raw),
            }),
            _ => {
                unreachable!()
            }
        }
    }
}

impl<I> Parse<CustomIdent> for Parser<I>
where
    I: ParserInput,
{
    fn parse(&mut self) -> PResult<CustomIdent> {
        let span = self.input.cur_span();

        if !is!(self, Ident) {
            return Err(Error::new(span, ErrorKind::Expected("Ident")));
        }

        match bump!(self) {
            Token::Ident { value, raw, .. } => {
                if matches_eq_ignore_ascii_case!(
                    value, "initial", "inherit", "unset", "revert", "default"
                ) {
                    return Err(Error::new(span, ErrorKind::InvalidCustomIdent(value)));
                }

                Ok(CustomIdent {
                    span,
                    value,
                    raw: Some(raw),
                })
            }
            _ => {
                unreachable!()

View on GitHub (pinned to 5176682b65)

Solutions

1. Provide an identifier token where a custom ident is expected
2. Quote strings explicitly if a string was intended

When it happens

Trigger: Thrown at crates/swc_css_parser/src/parser/values_and_units/mod.rs:1829 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of swc-project/swc@5176682b65 (2026-08-17). Data as JSON: /api/errors/80b4652373822ed6. Report an issue: GitHub.