fix #3426: improve invalid url() token parsing

Author: evanw

internal/css_parser/css_parser.go

@@ -974,12 +974,31 @@ func (p *parser) parseURLOrString() (string, logger.Range, bool) {
 	case css_lexer.TFunction:
 		if strings.EqualFold(p.decoded(), "url") {
 			matchingLoc := logger.Loc{Start: p.current().Range.End() - 1}
-			p.advance()
-			t = p.current()
-			text := p.decoded()
-			if p.expect(css_lexer.TString) {
-				p.expectWithMatchingLoc(css_lexer.TCloseParen, matchingLoc)
-				return text, t.Range, true
+			i := p.index + 1
+
+			// Skip over whitespace
+			for p.at(i).Kind == css_lexer.TWhitespace {
+				i++
+			}
+
+			// Consume a string
+			if p.at(i).Kind == css_lexer.TString {
+				stringIndex := i
+				i++
+
+				// Skip over whitespace
+				for p.at(i).Kind == css_lexer.TWhitespace {
+					i++
+				}
+
+				// Consume a closing parenthesis
+				if close := p.at(i).Kind; close == css_lexer.TCloseParen || close == css_lexer.TEndOfFile {
+					t := p.at(stringIndex)
+					text := t.DecodedText(p.source.Contents)
+					p.index = i
+					p.expectWithMatchingLoc(css_lexer.TCloseParen, matchingLoc)
+					return text, t.Range, true
+				}
 			}
 		}
 	}

internal/css_parser/css_parser_test.go

@@ -1302,15 +1302,19 @@ func TestAtImport(t *testing.T) {
 	expectPrinted(t, "@import url();", "@import \"\";\n", "")
 	expectPrinted(t, "@import url(foo.css);", "@import \"foo.css\";\n", "")
 	expectPrinted(t, "@import url(foo.css) ;", "@import \"foo.css\";\n", "")
+	expectPrinted(t, "@import url( foo.css );", "@import \"foo.css\";\n", "")
 	expectPrinted(t, "@import url(\"foo.css\");", "@import \"foo.css\";\n", "")
 	expectPrinted(t, "@import url(\"foo.css\") ;", "@import \"foo.css\";\n", "")
+	expectPrinted(t, "@import url( \"foo.css\" );", "@import \"foo.css\";\n", "")
 	expectPrinted(t, "@import url(\"foo.css\") print;", "@import \"foo.css\" print;\n", "")
 	expectPrinted(t, "@import url(\"foo.css\") screen and (orientation:landscape);", "@import \"foo.css\" screen and (orientation:landscape);\n", "")
 
 	expectPrinted(t, "@import;", "@import;\n", "<stdin>: WARNING: Expected URL token but found \";\"\n")
 	expectPrinted(t, "@import ;", "@import;\n", "<stdin>: WARNING: Expected URL token but found \";\"\n")
 	expectPrinted(t, "@import \"foo.css\"", "@import \"foo.css\";\n", "<stdin>: WARNING: Expected \";\" but found end of file\n")
-	expectPrinted(t, "@import url(\"foo.css\";", "@import \"foo.css\";\n", "<stdin>: WARNING: Expected \")\" to go with \"(\"\n<stdin>: NOTE: The unbalanced \"(\" is here:\n")
+	expectPrinted(t, "@import url(\"foo.css\" extra-stuff);", "@import url(\"foo.css\" extra-stuff);\n", "<stdin>: WARNING: Expected URL token but found \"url(\"\n")
+	expectPrinted(t, "@import url(\"foo.css\";", "@import url(\"foo.css\";);\n",
+		"<stdin>: WARNING: Expected URL token but found \"url(\"\n<stdin>: WARNING: Expected \")\" to go with \"(\"\n<stdin>: NOTE: The unbalanced \"(\" is here:\n")
 	expectPrinted(t, "@import noturl(\"foo.css\");", "@import noturl(\"foo.css\");\n", "<stdin>: WARNING: Expected URL token but found \"noturl(\"\n")
 	expectPrinted(t, "@import url(foo.css", "@import \"foo.css\";\n", `<stdin>: WARNING: Expected ")" to end URL token
 <stdin>: NOTE: The unbalanced "(" is here: