Remove empty lines at the beginning of the file

src/lib.rs

@@ -321,6 +321,7 @@ where
         let filemap = visitor.codemap.lookup_char_pos(module.inner.lo()).file;
         // Format inner attributes if available.
         if !krate.attrs.is_empty() && path == main_file {
+            visitor.skip_empty_lines(filemap.end_pos);
             if visitor.visit_attrs(&krate.attrs, ast::AttrStyle::Inner) {
                 visitor.push_rewrite(module.inner, None);
             } else {
@@ -328,6 +329,7 @@ where
             }
         } else {
             visitor.last_pos = filemap.start_pos;
+            visitor.skip_empty_lines(filemap.end_pos);
             visitor.format_separate_mod(module, &*filemap);
         };
 

src/visitor.rs

@@ -699,6 +699,20 @@ impl<'a> FmtVisitor<'a> {
         self.format_missing_with_indent(filemap.end_pos);
     }
 
+    pub fn skip_empty_lines(&mut self, end_pos: BytePos) {
+        while let Some(pos) = self.codemap
+            .opt_span_after(mk_sp(self.last_pos, end_pos), "\n")
+        {
+            if let Some(snippet) = self.opt_snippet(mk_sp(self.last_pos, pos)) {
+                if snippet.trim().is_empty() {
+                    self.last_pos = pos;
+                } else {
+                    return;
+                }
+            }
+        }
+    }
+
     pub fn get_context(&self) -> RewriteContext {
         RewriteContext {
             parse_session: self.parse_session,