CSS: Extended url inside (#1874)

This extends the highlighting of the CSS `url` pattern adding highlighting for punctuation and the `url` function.

components/prism-css.js

@@ -11,7 +11,13 @@
 				// See rest below
 			}
 		},
-		'url': RegExp('url\\((?:' + string.source + '|.*?)\\)', 'i'),
+		'url': {
+			pattern: RegExp('url\\((?:' + string.source + '|[^\n\r()]*)\\)', 'i'),
+			inside: {
+				'function': /^url/i,
+				'punctuation': /^\(|\)$/
+			}
+		},
 		'selector': RegExp('[^{}\\s](?:[^{};"\']|' + string.source + ')*?(?=\\s*\\{)'),
 		'string': {
 			pattern: string,

prism.js

@@ -679,7 +679,13 @@ Prism.languages.svg = Prism.languages.markup;
 				// See rest below
 			}
 		},
-		'url': RegExp('url\\((?:' + string.source + '|.*?)\\)', 'i'),
+		'url': {
+			pattern: RegExp('url\\((?:' + string.source + '|[^\n\r()]*)\\)', 'i'),
+			inside: {
+				'function': /^url/i,
+				'punctuation': /^\(|\)$/
+			}
+		},
 		'selector': RegExp('[^{}\\s](?:[^{};"\']|' + string.source + ')*?(?=\\s*\\{)'),
 		'string': {
 			pattern: string,

tests/languages/css/atrule_feature.test

@@ -10,7 +10,12 @@
 [
 	["atrule", [
 		["rule", "@import"],
-		["url", "url(foo.css)"],
+		["url", [
+			["function", "url"],
+			["punctuation", "("],
+			"foo.css",
+			["punctuation", ")"]
+		]],
 		["punctuation", ";"]
 	]],
 	["atrule", [
@@ -62,4 +67,4 @@
 ----------------------------------------------------
 
 Checks for at-rules.
-Also checks for LESS variables.
+Also checks for LESS variables.

tests/languages/css/url_feature.test

@@ -9,13 +9,38 @@ bar.png")
 ----------------------------------------------------
 
 [
-	["url", "url(foo.png)"],
-	["url", "url('foo.png')"],
-	["url", "url(\"foo.png\")"],
-	["url", "url('foo\\\r\nbar.png')"],
-	["url", "url(\"foo\\\r\nbar.png\")"]
+	["url", [
+		["function", "url"],
+		["punctuation", "("],
+		"foo.png",
+		["punctuation", ")"]
+	]],
+	["url", [
+		["function", "url"],
+		["punctuation", "("],
+		"'foo.png'",
+		["punctuation", ")"]
+	]],
+	["url", [
+		["function", "url"],
+		["punctuation", "("],
+		"\"foo.png\"",
+		["punctuation", ")"]
+	]],
+	["url", [
+		["function", "url"],
+		["punctuation", "("],
+		"'foo\\\r\nbar.png'",
+		["punctuation", ")"]
+	]],
+	["url", [
+		["function", "url"],
+		["punctuation", "("],
+		"\"foo\\\r\nbar.png\"",
+		["punctuation", ")"]
+	]]
 ]
 
 ----------------------------------------------------
 
-Checks for url(), unquoted, single-quoted and double-quoted.
+Checks for url(), unquoted, single-quoted and double-quoted.