swc-project/swc · error · Error

Expected whitespace, ';', '@', ident or EOF

Error message

Expected whitespace, ';', '@', ident or EOF

What it means

Fires in the declaration-or-at-rule parser when the current token cannot start a declaration or an at-rule. Per CSS Syntax Level 3, this is a parse error: the parser reconsumes the token and discards component values until a semicolon or EOF, recording this error so the invalid rule content is dropped rather than aborting the whole stylesheet.

Source

Thrown at crates/swc_css_parser/src/parser/syntax/mod.rs:563

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

                                DeclarationOrAtRule::ListOfComponentValues(Box::new(temporary_list))
                            }
                        };

                    declarations.push(decl_or_list_of_component_values);
                }
                // anything else
                // This is a parse error. Reconsume the current input token. As long as the next
                // input token is anything other than a <semicolon-token> or <EOF-token>, consume a
                // component value and throw away the returned value.
                //
                // We don't throw away the return value because of the recovery mode and return list
                // of components values in this case
                _ => {
                    let span = self.input.cur_span();

                    self.errors.push(Error::new(
                        span,
                        ErrorKind::Expected("whitespace, ';', '@', ident or EOF"),
                    ));

                    // 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);

View on GitHub (pinned to 5176682b65)

Solutions

1. Start declarations with a valid property ident or '@' for at-rules
2. Check for stray tokens (stray delimiters, unclosed strings) before the offending position
3. Remove or quote malformed content inside the rule block

When it happens

Trigger: Thrown at crates/swc_css_parser/src/parser/syntax/mod.rs:563 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/0051447e6d036291. Report an issue: GitHub.