escape all special chars within #id and .class CSS selectors

src/css.rs

@@ -24,6 +24,7 @@ const CSS_PROPS_WITH_IMAGE_URLS: &[&str] = &[
     "suffix",
     "symbols",
 ];
+const CSS_SPECIAL_CHARS: &str = "~!@$%^&*()+=,./'\";:?><[]{}|`#";
 
 pub fn is_image_url_prop(prop_name: &str) -> bool {
     CSS_PROPS_WITH_IMAGE_URLS
@@ -40,6 +41,18 @@ pub fn enquote(input: String, double: bool) -> String {
     }
 }
 
+pub fn escape(value: &str) -> String {
+    let mut res = str!(&value);
+
+    res = res.replace("\\", "\\\\");
+
+    for c in CSS_SPECIAL_CHARS.chars() {
+        res = res.replace(c, format!("\\{}", c).as_str());
+    }
+
+    res
+}
+
 pub fn process_css<'a>(
     cache: &mut HashMap<String, String>,
     client: &Client,
@@ -122,7 +135,7 @@ pub fn process_css<'a>(
             }
             Token::Ident(ref value) => {
                 curr_prop = str!(value);
-                result.push_str(&value.replace(":", "\\:"));
+                result.push_str(&escape(value));
             }
             Token::AtKeyword(ref value) => {
                 curr_rule = str!(value);
@@ -243,7 +256,7 @@ pub fn process_css<'a>(
             }
             Token::IDHash(ref value) => {
                 result.push_str("#");
-                result.push_str(value);
+                result.push_str(&escape(value));
             }
             Token::UnquotedUrl(ref value) => {
                 let is_import: bool = curr_rule == "import";

src/tests/css/embed_css.rs

@@ -225,7 +225,7 @@ div {\n    \
 }
 
 #[test]
-fn passing_colons_in_class_names() {
+fn passing_unusual_indents() {
     let cache = &mut HashMap::new();
     let client = Client::new();
 
@@ -233,6 +233,10 @@ fn passing_colons_in_class_names() {
 .is\\:good:hover {\n    \
     color: green\n\
 }\n\
+\n\
+#\\~\\!\\@\\$\\%\\^\\&\\*\\(\\)\\+\\=\\,\\.\\/\\\\\\'\\\"\\;\\:\\?\\>\\<\\[\\]\\{\\}\\|\\`\\# {\n    \
+    color: black\n\
+}\n\
 ";
 
     assert_eq!(