use Object.prototype.toString()

Author: pkaeding

index.js

@@ -469,6 +469,6 @@ function intersect_safe(a, b)
 
 function sanitize_user(u) {
   if (u['key']) {
-    u['key'] = "" + u['key'];
+    u['key'] = u['key'].toString();
   }
 }

test/test.js

@@ -171,4 +171,10 @@ describe('sanitize_user', function () {
     sanitize_user(u);
     assert.deepStrictEqual(u0, u);
   });
+  it('should not blow up if the key is missing', function () {
+    var u = {firstName: 'alice'};
+    var u0 = {firstName: 'alice'};
+    sanitize_user(u);
+    assert.deepStrictEqual(u0, u);
+  });
 });