expanded on migration support

migrations/utils.js

@@ -0,0 +1,19 @@
+/**
+ * processUpdates processes batches of updates on the given model.
+ *
+ * @param {Object} model mongoose model that should perform the operations on
+ * @param {Array<Object>} updates array of updates to execute
+ */
+const processUpdates = async (model, updates) => {
+  // Create a new batch operation.
+  const bulk = model.collection.initializeUnorderedBulkOp();
+
+  for (const { query, update } of updates) {
+    bulk.find(query).updateOne(update);
+  }
+
+  // Execute the bulk update operation.
+  await bulk.execute();
+};
+
+module.exports = { processUpdates };