allow whitespace after multiline comment in named args

src/utils/comment_whitespace.rs

@@ -50,7 +50,7 @@ pub(crate) fn peek_whitespace_or_comment(s: &mut PeekMoreIterator<IntoIter<Token
                 found_whitespace = true;
                 s.advance_cursor();
             }
-            '/' => match s.peek_forward(1) {
+            '/' => match s.peek_next() {
                 Some(Token { kind: '/', .. }) => {
                     peek_until_newline(s);
                     found_whitespace = true;
@@ -60,7 +60,8 @@ pub(crate) fn peek_whitespace_or_comment(s: &mut PeekMoreIterator<IntoIter<Token
                     while let Some(tok) = s.peek_next() {
                         match tok.kind {
                             '*' => {
-                                if matches!(s.peek_forward(1), Some(Token { kind: '/', .. })) {
+                                if matches!(s.peek_next(), Some(Token { kind: '/', .. })) {
+                                    s.advance_cursor();
                                     break;
                                 }
                             }

tests/args.rs

@@ -168,3 +168,14 @@ error!(
     filter_value_after_equal_is_last_char,
     "a {\n  color: foo(a=a", "Error: expected \")\"."
 );
+test!(
+    space_after_loud_comment,
+    "@mixin foo($x) {
+        color: $x;
+    }
+
+    a {
+      @include foo($x /* blah */ : kwd-y);
+    }",
+    "a {\n  color: kwd-y;\n}\n"
+);