encountering placeholder selector resets has_written

src/output.rs

@@ -125,7 +125,7 @@ impl Css {
                 let selector = selector.into_selector().remove_placeholders();
 
                 if selector.is_empty() {
-                    return Ok(Vec::new());
+                    return Ok(vec![Toplevel::new_rule(selector)]);
                 }
 
                 let mut vals = vec![Toplevel::new_rule(selector)];
@@ -494,6 +494,11 @@ impl Formatter for ExpandedFormatter {
         for block in css.blocks {
             match block {
                 Toplevel::RuleSet(selector, styles) => {
+                    if selector.is_empty() {
+                        has_written = false;
+                        continue;
+                    }
+
                     if styles.is_empty() {
                         continue;
                     }

tests/comments.rs

@@ -98,3 +98,45 @@ test!(
       /**/",
     "/**/\n/**/\n"
 );
+test!(
+    no_extra_newline_when_after_placeholder_selector,
+    r"a {
+      color: red;
+    
+      %b {
+        color: red;
+      }
+    }
+    
+    /**/
+    
+    c {
+      color: red;
+    }
+    
+    /**/",
+    "a {\n  color: red;\n}\n/**/\nc {\n  color: red;\n}\n\n/**/\n"
+);
+test!(
+    extra_newline_when_after_regular_selector_after_placeholder_selector,
+    r"a {
+      color: red;
+    
+      %b {
+        color: red;
+      }
+    
+      d {
+        color: red;
+      }
+    }
+    
+    /**/
+    
+    c {
+      color: red;
+    }
+    
+    /**/",
+    "a {\n  color: red;\n}\na d {\n  color: red;\n}\n\n/**/\nc {\n  color: red;\n}\n\n/**/\n"
+);

tests/selectors.rs

@@ -829,6 +829,21 @@ test!(
     "[a=\"a\\\\66  \"] {\n  color: &;\n}\n",
     "[a=\"a\\\\66  \"] {\n  color: [a=\"a\\\\66  \"];\n}\n"
 );
+test!(
+    no_newline_between_styles_when_last_style_was_placeholder,
+    "a {
+      color: red;
+    
+      %b {
+        color: red;
+      }
+    }
+    
+    c {
+      color: red;
+    }",
+    "a {\n  color: red;\n}\nc {\n  color: red;\n}\n"
+);
 error!(
     a_n_plus_b_n_invalid_odd,
     ":nth-child(ofdd) {\n  color: &;\n}\n", "Error: Expected \"odd\"."