Can I determine if a string is a MongoDB ObjectID?

Question

I am doing MongoDB lookups by converting a string to BSON. Is there a way for me to determine if the string I have is a valid ObjectID for Mongo before doing the conversion?

Answer 1

It took me a while to get a valid solution as the one proposed by @Andy Macleod of comparing objectId value with its own string was crashing the Express.js server on:

var view_task_id_temp=new mongodb.ObjectID("invalid_id_string"); //this crashed

I just used a simple try catch to solve this.

var mongodb = require('mongodb');
var id_error=false;
try{
    var x=new mongodb.ObjectID("57d9a8b310b45a383a74df93");
    console.log("x="+JSON.stringify(x));
}catch(err){
    console.log("error="+err);
    id_error=true;
}

if(id_error==false){
   // Do stuff here
}