css: fix parser recovery for rules without blocks

speedy-js · Mar 28, 2022 · 03fdb1a · 03fdb1a
1 parent 481288f
commit 03fdb1a
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Showing 3 changed files with 32 additions and 6 deletions.
diff --git a/internal/css_parser/css_parser.go b/internal/css_parser/css_parser.go
@@ -181,6 +181,7 @@ func (p *parser) parseListOfRules(context ruleContext) []css_ast.Rule {
 	if context.isTopLevel {
 		atRuleContext.charsetValidity = atRuleValid
 		atRuleContext.importValidity = atRuleValid
+		atRuleContext.isTopLevel = true
 	}
 	rules := []css_ast.Rule{}
 	didFindAtImport := false
@@ -271,9 +272,9 @@ loop:
 		}
 
 		if context.parseSelectors {
-			rules = append(rules, p.parseSelectorRuleFrom(p.index, parseSelectorOpts{}))
+			rules = append(rules, p.parseSelectorRuleFrom(p.index, parseSelectorOpts{isTopLevel: context.isTopLevel}))
 		} else {
-			rules = append(rules, p.parseQualifiedRuleFrom(p.index, false /* isAlreadyInvalid */))
+			rules = append(rules, p.parseQualifiedRuleFrom(p.index, parseQualifiedRuleOpts{isTopLevel: context.isTopLevel}))
 		}
 	}
 
@@ -704,6 +705,7 @@ type atRuleContext struct {
 	importValidity    atRuleValidity
 	isDeclarationList bool
 	allowNesting      bool
+	isTopLevel        bool
 }
 
 func (p *parser) parseAtRule(context atRuleContext) css_ast.Rule {
@@ -919,7 +921,11 @@ abortRuleParser:
 		p.eat(css_lexer.TWhitespace)
 		if kind := p.current().Kind; kind != css_lexer.TSemicolon && kind != css_lexer.TOpenBrace &&
 			kind != css_lexer.TCloseBrace && kind != css_lexer.TEndOfFile {
-			return p.parseSelectorRuleFrom(preludeStart-1, parseSelectorOpts{atNestRange: atRange, allowNesting: context.allowNesting})
+			return p.parseSelectorRuleFrom(preludeStart-1, parseSelectorOpts{
+				atNestRange:  atRange,
+				allowNesting: context.allowNesting,
+				isTopLevel:   context.isTopLevel,
+			})
 		}
 
 	case "layer":
@@ -1473,10 +1479,18 @@ func (p *parser) parseSelectorRuleFrom(preludeStart int, opts parseSelectorOpts)
 	}
 
 	// Otherwise, parse a generic qualified rule
-	return p.parseQualifiedRuleFrom(preludeStart, true /* isAlreadyInvalid */)
+	return p.parseQualifiedRuleFrom(preludeStart, parseQualifiedRuleOpts{
+		isAlreadyInvalid: true,
+		isTopLevel:       opts.isTopLevel,
+	})
 }
 
-func (p *parser) parseQualifiedRuleFrom(preludeStart int, isAlreadyInvalid bool) css_ast.Rule {
+type parseQualifiedRuleOpts struct {
+	isAlreadyInvalid bool
+	isTopLevel       bool
+}
+
+func (p *parser) parseQualifiedRuleFrom(preludeStart int, opts parseQualifiedRuleOpts) css_ast.Rule {
 	preludeLoc := p.tokens[preludeStart].Range.Loc
 
 loop:
@@ -1485,6 +1499,12 @@ loop:
 		case css_lexer.TOpenBrace, css_lexer.TEndOfFile:
 			break loop
 
+		case css_lexer.TCloseBrace:
+			if !opts.isTopLevel {
+				break loop
+			}
+			p.parseComponentValue()
+
 		default:
 			p.parseComponentValue()
 		}
@@ -1497,7 +1517,7 @@ loop:
 	if p.eat(css_lexer.TOpenBrace) {
 		qualified.Rules = p.parseListOfDeclarations()
 		p.expect(css_lexer.TCloseBrace)
-	} else if !isAlreadyInvalid {
+	} else if !opts.isAlreadyInvalid {
 		p.expect(css_lexer.TOpenBrace)
 	}
 

diff --git a/internal/css_parser/css_parser_selector.go b/internal/css_parser/css_parser_selector.go
@@ -51,6 +51,7 @@ func (p *parser) parseSelectorList(opts parseSelectorOpts) (list []css_ast.Compl
 type parseSelectorOpts struct {
 	atNestRange  logger.Range
 	allowNesting bool
+	isTopLevel   bool
 }
 
 func (p *parser) parseComplexSelector(opts parseSelectorOpts) (result css_ast.ComplexSelector, ok bool, hasNestPrefix bool) {

diff --git a/internal/css_parser/css_parser_test.go b/internal/css_parser/css_parser_test.go
@@ -775,6 +775,8 @@ func TestAtRule(t *testing.T) {
 	expectPrinted(t, "@-moz-document url-prefix() { h1 { color: green } }",
 		"@-moz-document url-prefix() {\n  h1 {\n    color: green;\n  }\n}\n")
 
+	expectPrinted(t, "@media foo { bar }", "@media foo {\n  bar {\n  }\n}\n")
+
 	// https://www.w3.org/TR/css-page-3/#syntax-page-selector
 	expectPrinted(t, `
 		@page :first { margin: 0 }
@@ -1100,6 +1102,9 @@ func TestEmptyRule(t *testing.T) {
 	expectPrintedMangleMinify(t, "@page { color: red; @top-left {} }", "@page{color:red}")
 	expectPrintedMangleMinify(t, "@keyframes test { from {} to { color: red } }", "@keyframes test{to{color:red}}")
 	expectPrintedMangleMinify(t, "@keyframes test { from { color: red } to {} }", "@keyframes test{0%{color:red}}")
+
+	expectPrinted(t, "invalid", "invalid {\n}\n")
+	expectPrinted(t, "invalid }", "invalid } {\n}\n")
 }
 
 func TestMarginAndPaddingAndInset(t *testing.T) {