fix(document): respect child schema minimize if toObject() is called without an explicit minimize

Fix #9405

Author: vkarpov15

lib/document.js

@@ -3078,13 +3078,14 @@ Document.prototype.$toObject = function(options, json) {
 
   // If options do not exist or is not an object, set it to empty object
   options = utils.isPOJO(options) ? clone(options) : {};
+  options._calledWithOptions = options._calledWithOptions || clone(options);
 
   if (!('flattenMaps' in options)) {
     options.flattenMaps = defaultOptions.flattenMaps;
   }
 
   let _minimize;
-  if (options.minimize != null) {
+  if (options._calledWithOptions.minimize != null) {
     _minimize = options.minimize;
   } else if (defaultOptions.minimize != null) {
     _minimize = defaultOptions.minimize;

test/utils.test.js

@@ -250,8 +250,6 @@ describe('utils', function() {
       assert.deepEqual(out.arr[0], { a: 42 });
       assert.deepEqual(out.arr[1], {});
       assert.deepEqual(out.arr[2], {});
-
-      return Promise.resolve();
     });
   });