Remove AtRuleType::OptionalBlock

Author: upsuper

src/css-parsing-tests/one_rule.json

@@ -7,13 +7,17 @@
 "@foo", ["at-rule", "foo", [], null],
 
 "@foo bar; \t/* comment */", ["at-rule", "foo", [" ", ["ident", "bar"]], null],
-" /**/ @foo bar{[(4", ["at-rule", "foo",
+" /**/ @foo-with-block bar{[(4", ["at-rule", "foo-with-block",
     [" ", ["ident", "bar"]],
     [["[]", ["()", ["number", "4", 4, "integer"]]]]
 ],
 
-"@foo { bar", ["at-rule", "foo", [" "], [" ", ["ident", "bar"]]],
-"@foo [ bar", ["at-rule", "foo", [" ", ["[]", " ", ["ident", "bar"]]], null],
+"@foo-with-block { bar", ["at-rule", "foo-with-block", [" "], [
+    " ", ["ident", "bar"]]
+],
+"@foo [ bar", ["at-rule", "foo",
+    [" ", ["[]", " ", ["ident", "bar"]]], null
+],
 
 " /**/ div > p { color: #aaa;  } /**/ ", ["qualified rule",
     [["ident", "div"], " ", ">", " ", ["ident", "p"], " "],

src/css-parsing-tests/rule_list.json

@@ -7,18 +7,20 @@
 "@foo", [["at-rule", "foo", [], null]],
 
 "@charset; @foo", [
-    ["at-rule", "charset", [], null],
+    ["error", "invalid"],
     ["at-rule", "foo", [], null]
 ],
 
 "@foo bar; \t/* comment */", [["at-rule", "foo", [" ", ["ident", "bar"]], null]],
 
-" /**/ @foo bar{[(4", [["at-rule", "foo",
+" /**/ @foo-with-block bar{[(4", [["at-rule", "foo-with-block",
     [" ", ["ident", "bar"]],
     [["[]", ["()", ["number", "4", 4, "integer"]]]]
 ]],
 
-"@foo { bar", [["at-rule", "foo", [" "], [" ", ["ident", "bar"]]]],
+"@foo-with-block { bar", [["at-rule", "foo-with-block", [" "], [
+    " ", ["ident", "bar"]]]
+],
 "@foo [ bar", [["at-rule", "foo", [" ", ["[]", " ", ["ident", "bar"]]], null]],
 
 " /**/ div > p { color: #aaa;  } /**/ ", [["qualified rule",

src/css-parsing-tests/stylesheet.json

@@ -10,17 +10,20 @@
 
 "@foo; @charset 4 {}", [
     ["at-rule", "foo", [], null],
-    ["at-rule", "charset", [" ", ["number", "4", 4, "integer"], " "], []]
+    ["error", "invalid"],
+    ["error", "invalid"]
 ],
 
 "@foo bar; \t/* comment */", [["at-rule", "foo", [" ", ["ident", "bar"]], null]],
 
-" /**/ @foo bar{[(4", [["at-rule", "foo",
+" /**/ @foo-with-block bar{[(4", [["at-rule", "foo-with-block",
 	[" ", ["ident", "bar"]],
 	[["[]", ["()", ["number", "4", 4, "integer"]]]]
 ]],
 
-"@foo { bar", [["at-rule", "foo", [" "], [" ", ["ident", "bar"]]]],
+"@foo-with-block { bar", [["at-rule", "foo-with-block", [" "], [
+    " ", ["ident", "bar"]]]
+],
 "@foo [ bar", [["at-rule", "foo", [" ", ["[]", " ", ["ident", "bar"]]], null]],
 
 " /**/ div > p { color: #aaa;  } /**/ ", [["qualified rule",

src/rules_and_declarations.rs

@@ -34,13 +34,6 @@ pub enum AtRuleType<P, R> {
     ///
     /// The value is the representation of the "prelude" part of the rule.
     WithBlock(P),
-
-    /// The at-rule may either have a block or end with a semicolon.
-    ///
-    /// This is mostly for testing. As of this writing no real CSS at-rule behaves like this.
-    ///
-    /// The value is the representation of the "prelude" part of the rule.
-    OptionalBlock(P),
 }
 
 /// A trait to provide various parsing of declaration values.
@@ -124,24 +117,14 @@ pub trait AtRuleParser<'i> {
     /// as returned by `RuleListParser::next` or `DeclarationListParser::next`,
     /// or `Err(())` to ignore the entire at-rule as invalid.
     ///
-    /// This is only called when `parse_prelude` returned `WithBlock` or `OptionalBlock`,
-    /// and a block was indeed found following the prelude.
+    /// This is only called when `parse_prelude` returned `WithBlock`, and a block
+    /// was indeed found following the prelude.
     fn parse_block<'t>(&mut self, prelude: Self::Prelude, input: &mut Parser<'i, 't>)
                        -> Result<Self::AtRule, ParseError<'i, Self::Error>> {
         let _ = prelude;
         let _ = input;
         Err(ParseError::Basic(BasicParseError::AtRuleBodyInvalid))
     }
-
-    /// An `OptionalBlock` prelude was followed by `;`.
-    ///
-    /// Convert the prelude into the finished representation of the at-rule
-    /// as returned by `RuleListParser::next` or `DeclarationListParser::next`.
-    fn rule_without_block(&mut self, prelude: Self::Prelude) -> Self::AtRule {
-        let _ = prelude;
-        panic!("The `AtRuleParser::rule_without_block` method must be overriden \
-                if `AtRuleParser::parse_prelude` ever returns `AtRuleType::OptionalBlock`.")
-    }
 }
 
 /// A trait to provide various parsing of qualified rules.
@@ -495,21 +478,6 @@ fn parse_at_rule<'i: 't, 't, P, E>(start: &ParserState, name: CowRcStr<'i>,
                 Ok(_) => unreachable!()
             }
         }
-        Ok(AtRuleType::OptionalBlock(prelude)) => {
-            match input.next() {
-                Ok(&Token::Semicolon) | Err(_) => Ok(parser.rule_without_block(prelude)),
-                Ok(&Token::CurlyBracketBlock) => {
-                    // FIXME: https://github.com/rust-lang/rust/issues/42508
-                    parse_nested_block::<'i, 't, _, _, _>(input, move |input| parser.parse_block(prelude, input))
-                        .map_err(|e| PreciseParseError {
-                            error: e,
-                            slice: input.slice_from(start.position()),
-                            location: start.source_location(),
-                        })
-                }
-                _ => unreachable!()
-            }
-        }
         Err(error) => {
             let end_position = input.position();
             match input.next() {

src/tests.rs

@@ -751,23 +751,26 @@ impl<'i> AtRuleParser<'i> for JsonParser {
 
     fn parse_prelude<'t>(&mut self, name: CowRcStr<'i>, input: &mut Parser<'i, 't>)
                          -> Result<AtRuleType<Vec<Json>, Json>, ParseError<'i, ()>> {
-        Ok(AtRuleType::OptionalBlock(vec![
+        let mut prelude = vec![
             "at-rule".to_json(),
             name.to_json(),
             Json::Array(component_values_to_json(input)),
-        ]))
+        ];
+        match_ignore_ascii_case! { &*name,
+            "media" | "foo-with-block" => Ok(AtRuleType::WithBlock(prelude)),
+            "charset" => Err(BasicParseError::AtRuleInvalid(name.clone()).into()),
+            _ => {
+                prelude.push(Json::Null);
+                Ok(AtRuleType::WithoutBlock(Json::Array(prelude)))
+            }
+        }
     }
 
     fn parse_block<'t>(&mut self, mut prelude: Vec<Json>, input: &mut Parser<'i, 't>)
                        -> Result<Json, ParseError<'i, ()>> {
         prelude.push(Json::Array(component_values_to_json(input)));
         Ok(Json::Array(prelude))
     }
-
-    fn rule_without_block(&mut self, mut prelude: Vec<Json>) -> Json {
-        prelude.push(Json::Null);
-        Json::Array(prelude)
-    }
 }
 
 impl<'i> QualifiedRuleParser<'i> for JsonParser {