Fix toString for namespaced variable (#1358)

CHANGELOG.md

@@ -3,6 +3,9 @@
 * Fix a couple bugs that could prevent some members from being found in certain
   files that use a mix of imports and the module system.
 
+* Fix incorrect recommendation for migrating division expressions that reference
+  namespaced variables.
+
 ## 1.34.1
 
 * Fix a bug where `--update` would always compile any file that depends on a

lib/src/ast/sass/expression/variable.dart

@@ -23,10 +23,5 @@ class VariableExpression implements Expression {
   T accept<T>(ExpressionVisitor<T> visitor) =>
       visitor.visitVariableExpression(this);
 
-  String toString() {
-    var buffer = StringBuffer("\$");
-    if (namespace != null) buffer.write("$namespace.");
-    buffer.write(name);
-    return buffer.toString();
-  }
+  String toString() => namespace == null ? '\$$name' : '$namespace.\$$name';
 }