bson: add cacheHexString boolean flag to ObjectID

types/bson/bson-tests.ts

@@ -1,5 +1,8 @@
 import * as bson from 'bson';
 
+// enable hex string caching
+bson.ObjectID.cacheHexString = true
+
 let BSON = new bson.BSON();
 let Long = bson.Long;
 

types/bson/index.d.ts

@@ -135,6 +135,10 @@ export class ObjectID {
     constructor(id?: string | number | ObjectID);
     /** The generation time of this ObjectID instance */
     generationTime: number;
+    /**
+     * If true cache the hex string representation of ObjectID instance
+     */
+    static cacheHexString?: boolean;
     /**
      * Creates an ObjectID from a hex string representation of an ObjectID.
      * @param {string} hexString create a ObjectID from a passed in 24 byte hexstring.