fix(document+schema): add potential fix for Automattic#15071

Author: vkarpov15

lib/document.js

@@ -1777,6 +1777,15 @@ Document.prototype.$__set = function(pathToMark, path, options, constructing, pa
  */
 
 Document.prototype.$__getValue = function(path) {
+  if (typeof path !== 'string' && !Array.isArray(path)) {
+    throw new TypeError(
+      'Invalid `path`. Must be either string or array. Got "' +
+      path +
+      '" (type ' +
+      typeof path +
+      ')'
+    );
+  }
   return utils.getValue(path, this._doc);
 };
 

lib/schema.js

@@ -1242,11 +1242,22 @@ function gatherChildSchemas(schema) {
   const childSchemas = [];
 
   for (const path of Object.keys(schema.paths)) {
+    if (typeof path !== 'string') {
+      continue;
+    }
     const schematype = schema.paths[path];
     if (schematype.$isMongooseDocumentArray || schematype.$isSingleNested) {
-      childSchemas.push({ schema: schematype.schema, model: schematype.caster, path: path });
+      childSchemas.push({
+        schema: schematype.schema,
+        model: schematype.caster,
+        path: path
+      });
     } else if (schematype.$isSchemaMap && schematype.$__schemaType.$isSingleNested) {
-      childSchemas.push({ schema: schematype.$__schemaType.schema, model: schematype.$__schemaType.caster, path: path });
+      childSchemas.push({
+        schema: schematype.$__schemaType.schema,
+        model: schematype.$__schemaType.caster,
+        path: path
+      });
     }
   }