fix(css/parser): Fix a bug with scope in block (#6402)

crates/swc_css_parser/src/parser/at_rules/mod.rs

@@ -565,7 +565,7 @@ where
             | js_word!("-o-keyframes")
             | js_word!("-ms-keyframes") => {
                 let ctx = Ctx {
-                    block_contents_grammar: BlockContentsGrammar::DeclarationList,
+                    block_contents_grammar: BlockContentsGrammar::RuleList,
                     is_top_level: false,
                     in_keyframes_at_rule: true,
                     ..self.ctx

crates/swc_css_parser/src/parser/syntax/mod.rs

@@ -134,24 +134,18 @@ where
                 unreachable!()
             }
         };
-        let (normalized_at_rule_name, name) = if at_keyword_name.0.starts_with("--") {
+        let name = if at_keyword_name.0.starts_with("--") {
-            (
-                at_keyword_name.0.to_ascii_lowercase(),
             AtRuleName::DashedIdent(DashedIdent {
                 span: Span::new(span.lo + BytePos(1), span.hi, Default::default()),
                 value: at_keyword_name.0,
                 raw: Some(at_keyword_name.1),
-                }),
+            })
-            )
         } else {
-            (
-                at_keyword_name.0.to_ascii_lowercase(),
             AtRuleName::Ident(Ident {
                 span: Span::new(span.lo + BytePos(1), span.hi, Default::default()),
                 value: at_keyword_name.0,
                 raw: Some(at_keyword_name.1),
-                }),
+            })
-            )
         };
         let mut prelude = vec![];
         let mut at_rule = AtRule {
@@ -181,103 +175,31 @@ where
                 tok!(";") => {
                     self.input.bump();
 
-                    let list_of_component_values = self.create_locv(prelude);
+                    at_rule.prelude = Some(Box::new(AtRulePrelude::ListOfComponentValues(
-
+                        self.create_locv(prelude),
-                    at_rule.prelude = match self
+                    )));
-                        .parse_according_to_grammar(&list_of_component_values, |parser| {
-                            parser.parse_at_rule_prelude(&normalized_at_rule_name)
-                        }) {
-                        Ok(at_rule_prelude) => match at_rule_prelude {
-                            None if normalized_at_rule_name == js_word!("layer") => {
-                                self.errors.push(Error::new(
-                                    span,
-                                    ErrorKind::Expected("at least one name"),
-                                ));
-
-                                Some(Box::new(AtRulePrelude::ListOfComponentValues(
-                                    list_of_component_values,
-                                )))
-                            }
-                            _ => at_rule_prelude.map(Box::new),
-                        },
-                        Err(err) => {
-                            if *err.kind() != ErrorKind::Ignore {
-                                self.errors.push(err);
-                            }
-
-                            if !list_of_component_values.children.is_empty() {
-                                Some(Box::new(AtRulePrelude::ListOfComponentValues(
-                                    list_of_component_values,
-                                )))
-                            } else {
-                                None
-                            }
-                        }
-                    };
                     at_rule.span = span!(self, span.lo);
 
+                    // Canonicalization against a grammar
+                    at_rule = self.canonicalize_at_rule_prelude(at_rule)?;
+
                     return Ok(at_rule);
                 }
                 // <{-token>
                 // Consume a simple block and assign it to the at-rule’s block. Return the at-rule.
                 tok!("{") => {
-                    let mut block = self.parse_as::<SimpleBlock>()?;
+                    let block = self.parse_as::<SimpleBlock>()?;
 
-                    let list_of_component_values = self.create_locv(prelude);
+                    at_rule.prelude = Some(Box::new(AtRulePrelude::ListOfComponentValues(
-
+                        self.create_locv(prelude),
-                    at_rule.prelude = match self
+                    )));
-                        .parse_according_to_grammar(&list_of_component_values, |parser| {
+                    at_rule.block = Some(block);
-                            parser.parse_at_rule_prelude(&normalized_at_rule_name)
-                        }) {
-                        Ok(at_rule_prelude) => match at_rule_prelude {
-                            Some(AtRulePrelude::LayerPrelude(LayerPrelude::NameList(
-                                name_list,
-                            ))) if name_list.name_list.len() > 1 => {
-                                self.errors.push(Error::new(
-                                    name_list.span,
-                                    ErrorKind::Expected("only one name"),
-                                ));
-
-                                Some(Box::new(AtRulePrelude::ListOfComponentValues(
-                                    list_of_component_values,
-                                )))
-                            }
-                            _ => at_rule_prelude.map(Box::new),
-                        },
-                        Err(err) => {
-                            if *err.kind() != ErrorKind::Ignore {
-                                self.errors.push(err);
-                            }
-
-                            if !list_of_component_values.children.is_empty() {
-                                Some(Box::new(AtRulePrelude::ListOfComponentValues(
-                                    list_of_component_values,
-                                )))
-                            } else {
-                                None
-                            }
-                        }
-                    };
-
-                    at_rule.block = match self.parse_according_to_grammar(
-                        &self.create_locv(block.value.clone()),
-                        |parser| parser.parse_at_rule_block(&normalized_at_rule_name),
-                    ) {
-                        Ok(block_contents) => {
-                            block.value = block_contents;
-
-                            Some(block)
-                        }
-                        Err(err) => {
-                            if *err.kind() != ErrorKind::Ignore {
-                                self.errors.push(err);
-                            }
-
-                            Some(block)
-                        }
-                    };
                     at_rule.span = span!(self, span.lo);
 
+                    // Canonicalization against a grammar
+                    at_rule = self.canonicalize_at_rule_prelude(at_rule)?;
+                    at_rule = self.canonicalize_at_rule_block(at_rule)?;
+
                     return Ok(at_rule);
                 }
                 // anything else
@@ -299,50 +221,10 @@ where
 {
     fn parse(&mut self) -> PResult<QualifiedRule> {
         // To consume a qualified rule:
-        let create_prelude =
-            |p: &mut Parser<I>, list: Vec<ComponentValue>| -> PResult<QualifiedRulePrelude> {
-                let list_of_component_values = p.create_locv(list);
 
-                if p.ctx.in_keyframes_at_rule {
-                    Ok(QualifiedRulePrelude::ListOfComponentValues(
-                        list_of_component_values,
-                    ))
-                } else if p.ctx.mixed_with_declarations {
-                    match p.parse_according_to_grammar::<RelativeSelectorList>(
-                        &list_of_component_values,
-                        |parser| parser.parse(),
-                    ) {
-                        Ok(relative_selector_list) => Ok(
-                            QualifiedRulePrelude::RelativeSelectorList(relative_selector_list),
-                        ),
-                        Err(err) => {
-                            p.errors.push(err);
-
-                            Ok(QualifiedRulePrelude::ListOfComponentValues(
-                                list_of_component_values,
-                            ))
-                        }
-                    }
-                } else {
-                    match p.parse_according_to_grammar::<SelectorList>(
-                        &list_of_component_values,
-                        |parser| parser.parse(),
-                    ) {
-                        Ok(selector_list) => Ok(QualifiedRulePrelude::SelectorList(selector_list)),
-                        Err(err) => {
-                            p.errors.push(err);
-
-                            Ok(QualifiedRulePrelude::ListOfComponentValues(
-                                list_of_component_values,
-                            ))
-                        }
-                    }
-                }
-            };
-
-        let span = self.input.cur_span();
         // Create a new qualified rule with its prelude initially set to an empty list,
         // and its value initially set to nothing.
+        let span = self.input.cur_span();
         let mut prelude = vec![];
 
         // Repeatedly consume the next input token:
@@ -375,30 +257,20 @@ where
                 // Consume a simple block and assign it to the qualified rule’s block. Return the
                 // qualified rule.
                 tok!("{") => {
-                    let mut block = self.parse_as::<SimpleBlock>()?;
+                    let block = self.parse_as::<SimpleBlock>()?;
-
+                    let mut qualified_rule = QualifiedRule {
-                    block.value = match self.ctx.block_contents_grammar {
+                        span: span!(self, span.lo),
-                        BlockContentsGrammar::DeclarationList => self
+                        prelude: QualifiedRulePrelude::ListOfComponentValues(
-                            .parse_according_to_grammar(&self.create_locv(block.value), |parser| {
+                            self.create_locv(prelude),
-                                parser.parse_as::<Vec<DeclarationOrAtRule>>()
+                        ),
-                            })?
+                        block,
-                            .into_iter()
-                            .map(ComponentValue::DeclarationOrAtRule)
-                            .collect(),
-                        _ => self
-                            .parse_according_to_grammar(&self.create_locv(block.value), |parser| {
-                                parser.parse_as::<Vec<StyleBlock>>()
-                            })?
-                            .into_iter()
-                            .map(ComponentValue::StyleBlock)
-                            .collect(),
                     };
 
-                    return Ok(QualifiedRule {
+                    // Canonicalization against a grammar
-                        span: span!(self, span.lo),
+                    qualified_rule = self.canonicalize_qualified_rule_prelude(qualified_rule)?;
-                        prelude: create_prelude(self, prelude)?,
+                    qualified_rule = self.canonicalize_qualified_rule_block(qualified_rule)?;
-                        block,
+
-                    });
+                    return Ok(qualified_rule);
                 }
                 // Reconsume the current input token. Consume a component value. Append the returned
                 // value to the qualified rule’s prelude.
@@ -458,12 +330,7 @@ where
                 // Reconsume the current input token. Consume an at-rule, and append the result to
                 // rules.
                 tok!("@") => {
-                    let at_rule = self
+                    let at_rule = self.parse()?;
-                        .with_ctx(Ctx {
-                            block_contents_grammar: BlockContentsGrammar::StyleBlock,
-                            ..self.ctx
-                        })
-                        .parse_as::<AtRule>()?;
 
                     rules.push(StyleBlock::AtRule(Box::new(at_rule)));
                 }
@@ -880,32 +747,8 @@ where
             return Ok(declaration);
         }
 
-        // Grammar parsing
+        // Canonicalization against a grammar
-        let list_of_component_values = self.create_locv(declaration.value);
+        declaration = self.canonicalize_declaration_value(declaration)?;
-
-        declaration.value =
-            match self.parse_according_to_grammar(&list_of_component_values, |parser| {
-                let mut values = vec![];
-
-                loop {
-                    if is!(parser, EOF) {
-                        break;
-                    }
-
-                    values.push(parser.parse_generic_value()?);
-                }
-
-                Ok(values)
-            }) {
-                Ok(values) => values,
-                Err(err) => {
-                    if *err.kind() != ErrorKind::Ignore {
-                        self.errors.push(err);
-                    }
-
-                    list_of_component_values.children
-                }
-            };
 
         // 8. Return the declaration.
         Ok(declaration)
@@ -1055,9 +898,8 @@ where
                 unreachable!()
             }
         };
-        let function_name = &*ident.0.to_ascii_lowercase();
         let name = Ident {
-            span: swc_common::Span::new(span.lo, span.hi - BytePos(1), Default::default()),
+            span: Span::new(span.lo, span.hi - BytePos(1), Default::default()),
             value: ident.0,
             raw: Some(ident.1),
         };
@@ -1101,26 +943,8 @@ where
 
         function.span = span!(self, span.lo);
 
-        // Grammar parsing
+        // Canonicalization against a grammar
-        match self.ctx.block_contents_grammar {
+        function = self.canonicalize_function_value(function)?;
-            BlockContentsGrammar::DeclarationList => {}
-            _ => {
-                let locv = self.create_locv(function.value);
-
-                function.value = match self.parse_according_to_grammar(&locv, |parser| {
-                    parser.parse_function_values(function_name)
-                }) {
-                    Ok(values) => values,
-                    Err(err) => {
-                        if *err.kind() != ErrorKind::Ignore {
-                            self.errors.push(err);
-                        }
-
-                        locv.children
-                    }
-                };
-            }
-        }
 
         return Ok(function);
     }

crates/swc_css_parser/src/parser/util.rs

@@ -1,5 +1,6 @@
 use std::ops::{Deref, DerefMut};
 
+use swc_atoms::js_word;
 use swc_common::{Span, Spanned, SyntaxContext, DUMMY_SP};
 use swc_css_ast::*;
 
@@ -7,7 +8,7 @@ use super::{
     input::{Input, InputType, ParserInput},
     Ctx, Error, PResult, Parse, Parser,
 };
-use crate::parser::BlockContentsGrammar;
+use crate::{error::ErrorKind, parser::BlockContentsGrammar};
 
 impl<I> Parser<I>
 where
@@ -74,6 +75,255 @@ where
         res
     }
 
+    pub(super) fn canonicalize_at_rule_prelude(&mut self, mut at_rule: AtRule) -> PResult<AtRule> {
+        let normalized_at_rule_name = match &at_rule.name {
+            AtRuleName::Ident(Ident { value, .. }) => value.to_ascii_lowercase(),
+            AtRuleName::DashedIdent(_) => return Ok(at_rule),
+        };
+
+        let list_of_component_values = match at_rule.prelude {
+            Some(at_rule_prelude) => match *at_rule_prelude {
+                AtRulePrelude::ListOfComponentValues(list_of_component_values) => {
+                    list_of_component_values
+                }
+                _ => {
+                    unreachable!();
+                }
+            },
+            _ => {
+                unreachable!();
+            }
+        };
+
+        at_rule.prelude = match self
+            .parse_according_to_grammar(&list_of_component_values, |parser| {
+                parser.parse_at_rule_prelude(&normalized_at_rule_name)
+            }) {
+            Ok(at_rule_prelude) => match at_rule_prelude {
+                Some(AtRulePrelude::LayerPrelude(LayerPrelude::NameList(name_list)))
+                    if name_list.name_list.len() > 1 && at_rule.block.is_some() =>
+                {
+                    self.errors.push(Error::new(
+                        name_list.span,
+                        ErrorKind::Expected("only one name"),
+                    ));
+
+                    Some(Box::new(AtRulePrelude::ListOfComponentValues(
+                        list_of_component_values,
+                    )))
+                }
+                None if *normalized_at_rule_name == js_word!("layer")
+                    && at_rule.block.is_none() =>
+                {
+                    self.errors.push(Error::new(
+                        at_rule.span,
+                        ErrorKind::Expected("at least one name"),
+                    ));
+
+                    Some(Box::new(AtRulePrelude::ListOfComponentValues(
+                        list_of_component_values,
+                    )))
+                }
+                _ => at_rule_prelude.map(Box::new),
+            },
+            Err(err) => {
+                if *err.kind() != ErrorKind::Ignore {
+                    self.errors.push(err);
+                }
+
+                if !list_of_component_values.children.is_empty() {
+                    Some(Box::new(AtRulePrelude::ListOfComponentValues(
+                        list_of_component_values,
+                    )))
+                } else {
+                    None
+                }
+            }
+        };
+
+        Ok(at_rule)
+    }
+
+    pub(super) fn canonicalize_at_rule_block(&mut self, mut at_rule: AtRule) -> PResult<AtRule> {
+        let normalized_at_rule_name = match &at_rule.name {
+            AtRuleName::Ident(Ident { value, .. }) => value.to_ascii_lowercase(),
+            AtRuleName::DashedIdent(_) => return Ok(at_rule),
+        };
+
+        let mut block = match at_rule.block {
+            Some(simple_block) => simple_block,
+            _ => {
+                unreachable!();
+            }
+        };
+
+        let list_of_component_values = self.create_locv(block.value);
+
+        block.value = match self.parse_according_to_grammar(&list_of_component_values, |parser| {
+            parser.parse_at_rule_block(&normalized_at_rule_name)
+        }) {
+            Ok(block_contents) => block_contents,
+            Err(err) => {
+                if *err.kind() != ErrorKind::Ignore {
+                    self.errors.push(err);
+                }
+
+                list_of_component_values.children
+            }
+        };
+
+        at_rule.block = Some(block);
+
+        Ok(at_rule)
+    }
+
+    pub(super) fn canonicalize_qualified_rule_prelude(
+        &mut self,
+        mut qualified_rule: QualifiedRule,
+    ) -> PResult<QualifiedRule> {
+        let list_of_component_values = match qualified_rule.prelude {
+            QualifiedRulePrelude::ListOfComponentValues(list_of_component_values) => {
+                list_of_component_values
+            }
+            _ => {
+                unreachable!();
+            }
+        };
+
+        qualified_rule.prelude = if self.ctx.in_keyframes_at_rule {
+            QualifiedRulePrelude::ListOfComponentValues(list_of_component_values)
+        } else if self.ctx.mixed_with_declarations {
+            match self.parse_according_to_grammar::<RelativeSelectorList>(
+                &list_of_component_values,
+                |parser| parser.parse(),
+            ) {
+                Ok(relative_selector_list) => {
+                    QualifiedRulePrelude::RelativeSelectorList(relative_selector_list)
+                }
+                Err(err) => {
+                    self.errors.push(err);
+
+                    QualifiedRulePrelude::ListOfComponentValues(list_of_component_values)
+                }
+            }
+        } else {
+            match self
+                .parse_according_to_grammar::<SelectorList>(&list_of_component_values, |parser| {
+                    parser.parse()
+                }) {
+                Ok(selector_list) => QualifiedRulePrelude::SelectorList(selector_list),
+                Err(err) => {
+                    self.errors.push(err);
+
+                    QualifiedRulePrelude::ListOfComponentValues(list_of_component_values)
+                }
+            }
+        };
+
+        Ok(qualified_rule)
+    }
+
+    pub(super) fn canonicalize_qualified_rule_block(
+        &mut self,
+        mut qualified_rule: QualifiedRule,
+    ) -> PResult<QualifiedRule> {
+        qualified_rule.block.value = match self.ctx.block_contents_grammar {
+            BlockContentsGrammar::RuleList if self.ctx.in_keyframes_at_rule => self
+                .parse_according_to_grammar(
+                    &self.create_locv(qualified_rule.block.value),
+                    |parser| {
+                        parser
+                            .with_ctx(Ctx {
+                                block_contents_grammar: BlockContentsGrammar::DeclarationList,
+                                ..parser.ctx
+                            })
+                            .parse_as::<Vec<DeclarationOrAtRule>>()
+                    },
+                )?
+                .into_iter()
+                .map(ComponentValue::DeclarationOrAtRule)
+                .collect(),
+            _ => self
+                .parse_according_to_grammar(
+                    &self.create_locv(qualified_rule.block.value),
+                    |parser| {
+                        parser
+                            .with_ctx(Ctx {
+                                block_contents_grammar: BlockContentsGrammar::StyleBlock,
+                                ..parser.ctx
+                            })
+                            .parse_as::<Vec<StyleBlock>>()
+                    },
+                )?
+                .into_iter()
+                .map(ComponentValue::StyleBlock)
+                .collect(),
+        };
+
+        Ok(qualified_rule)
+    }
+
+    pub(super) fn canonicalize_function_value(
+        &mut self,
+        mut function: Function,
+    ) -> PResult<Function> {
+        match self.ctx.block_contents_grammar {
+            BlockContentsGrammar::DeclarationList => {}
+            _ => {
+                let function_name = function.name.value.to_ascii_lowercase();
+
+                let locv = self.create_locv(function.value);
+
+                function.value = match self.parse_according_to_grammar(&locv, |parser| {
+                    parser.parse_function_values(&function_name)
+                }) {
+                    Ok(values) => values,
+                    Err(err) => {
+                        if *err.kind() != ErrorKind::Ignore {
+                            self.errors.push(err);
+                        }
+
+                        locv.children
+                    }
+                };
+            }
+        }
+
+        Ok(function)
+    }
+
+    pub(super) fn canonicalize_declaration_value(
+        &mut self,
+        mut declaration: Declaration,
+    ) -> PResult<Declaration> {
+        let locv = self.create_locv(declaration.value);
+
+        declaration.value = match self.parse_according_to_grammar(&locv, |parser| {
+            let mut values = vec![];
+
+            loop {
+                if is!(parser, EOF) {
+                    break;
+                }
+
+                values.push(parser.parse_generic_value()?);
+            }
+
+            Ok(values)
+        }) {
+            Ok(values) => values,
+            Err(err) => {
+                if *err.kind() != ErrorKind::Ignore {
+                    self.errors.push(err);
+                }
+
+                locv.children
+            }
+        };
+
+        Ok(declaration)
+    }
+
     pub(super) fn try_to_parse_legacy_nesting(&mut self) -> Option<QualifiedRule> {
         let state = self.input.state();
         let qualified_rule = self

crates/swc_css_parser/src/parser/values_and_units/mod.rs

@@ -266,6 +266,7 @@ where
         Ok(tokens)
     }
 
+    // TODO use `JsWord`
     pub fn parse_function_values(&mut self, function_name: &str) -> PResult<Vec<ComponentValue>> {
         let mut values = vec![];
 

crates/swc_css_parser/tests/recovery/at-rule/layer/empty/output.swc-stderr

@@ -2,5 +2,5 @@
   x Expected at least one name
    ,-[$DIR/tests/recovery/at-rule/layer/empty/input.css:1:1]
  1 | @layer ;
-   : ^^^^^^
+   : ^^^^^^^^
    `----