diff --git a/lib/src/tree_base.dart b/lib/src/tree_base.dart
index d8fee1d..5011f3d 100644
--- a/lib/src/tree_base.dart
+++ b/lib/src/tree_base.dart
@@ -57,21 +57,23 @@
   }
 
   String toValue(value) {
-    if (value == null)
+    if (value == null) {
       return 'null';
-    else if (value is Identifier)
+    } else if (value is Identifier) {
       return value.name;
-    else
+    } else {
       return value.toString();
+    }
   }
 
   void writeNode(String label, TreeNode node) {
     write('${label}: ');
     depth += 1;
-    if (node != null)
+    if (node != null) {
       node.visit(printer);
-    else
+    } else {
       writeln('null');
+    }
     depth -= 1;
   }
 
diff --git a/test/samples_test.dart b/test/samples_test.dart
index 4059543..afba147 100644
--- a/test/samples_test.dart
+++ b/test/samples_test.dart
@@ -25,8 +25,9 @@
 main() {
   final libraryUri = currentMirrorSystem().findLibrary(#samples_test).uri;
   final cssDir = Directory.fromUri(libraryUri.resolve('examples'));
-  for (var element in cssDir.listSync())
+  for (var element in cssDir.listSync()) {
     if (element is File && element.uri.pathSegments.last.endsWith('.css')) {
       test(element.uri.pathSegments.last, () => testCSSFile(element));
     }
+  }
 }