swc-project/swc · error · Error

Unexpected token

Error message

Unexpected token

What it means

While parsing a style block's rule list, a QualifiedRule failed to parse; recovery pushes this error into self.errors and skips tokens to continue. 'Unexpected token' marks input at that position that the rule grammar cannot accept.

Source

Thrown at crates/swc_css_parser/src/parser/syntax/mod.rs:441

                    let state = self.input.state();
                    let qualified_rule = self
                        .with_ctx(Ctx {
                            block_contents_grammar: BlockContentsGrammar::StyleBlock,
                            mixed_with_declarations: true,
                            ..self.ctx
                        })
                        .parse_as::<Box<QualifiedRule>>();

                    match qualified_rule {
                        Ok(i) => rules.push(StyleBlock::QualifiedRule(i)),
                        Err(err) => {
                            self.errors.push(err);
                            self.input.reset(&state);

                            let span = self.input.cur_span();

                            self.errors
                                .push(Error::new(span, ErrorKind::Unexpected("token")));

                            // For recovery mode
                            let mut list_of_component_values = ListOfComponentValues {
                                span: Default::default(),
                                children: Vec::new(),
                            };

                            while !is_one_of!(self, ";", EOF) {
                                let component_value = self.parse_as::<ComponentValue>()?;

                                list_of_component_values.children.push(component_value);
                            }

                            list_of_component_values.span = span!(self, span.lo);

                            declarations.push(StyleBlock::ListOfComponentValues(Box::new(
                                list_of_component_values,
                            )));

View on GitHub (pinned to 5176682b65)

Solutions

1. Inspect the collected errors to locate the offending token
2. Fix the selector/rule syntax in the style block
3. Use the recovery results to skip and keep parsing the rest of the sheet

When it happens

Trigger: Thrown at crates/swc_css_parser/src/parser/syntax/mod.rs:441 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of swc-project/swc@5176682b65 (2026-08-17). Data as JSON: /api/errors/949d4ff414678b4d. Report an issue: GitHub.