swc-project/swc · error · Error

Expected integer type

Error message

Expected integer type

What it means

Fired by the Integer parser: a Number token was found but its type_flag is Number (has a fractional part or exponent), not Integer. Only <integer>-typed number tokens (e.g. '3', '-2') can become an Integer node; '3.5' or '1e2' are rejected.

Source

Thrown at crates/swc_css_parser/src/parser/values_and_units/mod.rs:1779

{
    fn parse(&mut self) -> PResult<Integer> {
        let span = self.input.cur_span();

        if !is!(self, Number) {
            return Err(Error::new(span, ErrorKind::ExpectedNumber));
        }

        let value = bump!(self);

        match value {
            Token::Number {
                value,
                raw,
                type_flag,
                ..
            } => {
                if type_flag == NumberType::Number {
                    return Err(Error::new(span, ErrorKind::Expected("integer type")));
                }

                Ok(Integer {
                    span,
                    value: value.round() as i64,
                    raw: Some(raw),
                })
            }
            _ => {
                unreachable!()
            }
        }
    }
}

impl<I> Parse<Number> for Parser<I>
where
    I: ParserInput,

View on GitHub (pinned to 5176682b65)

Solutions

1. Use a whole number without a decimal point or exponent
2. Round or floor the value if an integer is required by the grammar

When it happens

Trigger: Thrown at crates/swc_css_parser/src/parser/values_and_units/mod.rs:1779 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/16816032e831ea20. Report an issue: GitHub.