Devour whitespace after {

src/mixin.rs

@@ -50,6 +50,8 @@ impl Mixin {
             _ => return Err((pos, String::from("expected `(` or `{`"))),
         };
 
+        devour_whitespace(toks);
+
         let mut nesting = 1;
         let mut body = Vec::new();
 

src/selector.rs

@@ -127,12 +127,7 @@ impl Display for SelectorKind {
             SelectorKind::Attribute(attr) => write!(f, "{}", attr),
             SelectorKind::Pseudo(s) => write!(f, ":{}", s),
             SelectorKind::PseudoElement(s) => write!(f, "::{}", s),
-            SelectorKind::PseudoParen(s, val) => write!(
+            SelectorKind::PseudoParen(s, val) => write!(f, ":{}({})", s, val),
-                f,
-                ":{}({})",
-                s,
-                val
-            ),
             SelectorKind::Super | SelectorKind::None | SelectorKind::InterpolatedSuper => {
                 write!(f, "")
             }
@@ -239,7 +234,8 @@ impl<'a> SelectorParser<'a> {
                                 toks.push(' ');
                             }
                         }
-                        self.selectors.push(SelectorKind::PseudoParen(s, toks.trim_end().to_owned()))
+                        self.selectors
+                            .push(SelectorKind::PseudoParen(s, toks.trim_end().to_owned()))
                     } else {
                         self.selectors.push(SelectorKind::Pseudo(s))
                     }

tests/mixins.rs

@@ -9,6 +9,11 @@ test!(
     "b {\n  color: red;\n}\n"
 );
 test!(empty_mixin, "@mixin a {}\n\nb {\n  @include a;\n}\n", "");
+test!(
+    just_a_comment,
+    "@mixin foo() {\n  /* begin foo */\n}\n\na {\n    @include foo();\n}\n",
+    "a {\n  /* begin foo */\n}\n"
+);
 test!(
     mixin_two_styles,
     "@mixin a {\n  color: red;\n  color: blue;\n}\n\nb {\n  @include a;\n}\n",