swc-project/swc · error · Error

Unexpected ')' in declaration value

Error message

Unexpected ')' in declaration value

What it means

Fired by the declaration-value validator: a preserved ')' token (or other listed invalid preserved token such as bad string/bad url) appears inside a declaration value where no matching open block exists. Unbalanced closers are a CSS parse error, so the value is reported as invalid.

Source

Thrown at crates/swc_css_parser/src/parser/util.rs:386

        &mut self,
        component_value: &ComponentValue,
    ) -> PResult<()> {
        let ComponentValue::PreservedToken(preserved_token) = component_value else {
            return Ok(());
        };

        let kind = match preserved_token.token {
            Token::BadString { .. } => ErrorKind::Unexpected("bad string in declaration value"),
            Token::BadUrl { .. } => ErrorKind::Unexpected("bad url in declaration value"),
            Token::RParen => ErrorKind::Unexpected("')' in declaration value"),
            Token::RBracket => ErrorKind::Unexpected("']' in declaration value"),
            Token::RBrace => ErrorKind::Unexpected("'}' in declaration value"),
            Token::Semi => ErrorKind::Unexpected("';' in declaration value"),
            Token::Delim { value: '!' } => ErrorKind::Unexpected("'!' in declaration value"),
            _ => return Ok(()),
        };

        Err(Error::new(preserved_token.span, kind))
    }
}

pub(super) struct WithCtx<'w, I: 'w + ParserInput> {
    inner: &'w mut Parser<I>,
    orig_ctx: Ctx,
}

impl<I: ParserInput> Deref for WithCtx<'_, I> {
    type Target = Parser<I>;

    fn deref(&self) -> &Parser<I> {
        self.inner
    }
}
impl<I: ParserInput> DerefMut for WithCtx<'_, I> {
    fn deref_mut(&mut self) -> &mut Parser<I> {
        self.inner

View on GitHub (pinned to 5176682b65)

Solutions

1. Remove the stray ')' or add the matching opening '(' block
2. Rebalance parentheses inside the declaration value

When it happens

Trigger: Thrown at crates/swc_css_parser/src/parser/util.rs:386 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/0b900e9137b9d93e. Report an issue: GitHub.