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

I have used the native node mongodb driver to do this in the past. The isValid method checks that the value is a valid BSON ObjectId. See the documentation here.

var ObjectID = require('mongodb').ObjectID;
console.log( ObjectID.isValid(12345) );

Answer 2

If you are using Mongoose, we can test whether a String is of 12 bytes or a string of 24 hex characters by using isValidObjectId.

mongoose.isValidObjectId(string) will return true/false

This is a upgraded solution provided by accepted solution .

Answer 3

The easiest way is basically wrap your ObjectId method in a try and catch service. Then you are using this service to handle Objecet Id's, instead of using the method directly:

var ObjectId = REQUIRE OR IMPORT ...

// service
function oid(str) {
 try {   
   return ObjectId(str);
 } catch(err) {
   return false;
 }
}

// usage
if (oid(USER_INPUT)) {
  // continue
} else {
  // throw error
}

You can also send null or empty props to get a new generated ID.

Answer 4

In the solution answer Andy Macleod said:

What has been working for me is casting a string to an objectId and then checking that the original string matches the string value of the objectId.

new ObjectId('timtamtomted'); //616273656e6365576f726b73
new ObjectId('537eed02ed345b2e039652d2') //537eed02ed345b2e039652d2

This work because valid ids do not change when casted to an ObjectId but a string that gets a false valid will change when casted to an objectId.

An implementation of this approach, would be a function that checks if the passed value is a valid ObjectId and works with both string and ObjectId (object) values. It would look something like this:

var ObjectId = require("mongoose");.Types.ObjectId;

function isValidObjectId(value) {
  // If value is an object (ObjectId) cast it to a string
  var valueString = typeof value === "string" ? value : String(value); 

  // Cast the string to ObjectId
  var idInstance = new ObjectId(valueString); 

  return String(idInstance) === valueString;
}

Answer 5

mongoose.Types.ObjectId.isValid(string) always returns True if string contains 12 letters

let firstUserID = '5b360fdea392d731829ded18';
let secondUserID = 'aaaaaaaaaaaa';

console.log(mongoose.Types.ObjectId.isValid(firstUserID)); // true
console.log(mongoose.Types.ObjectId.isValid(secondUserID)); // true

let checkForValidMongoDbID = new RegExp("^[0-9a-fA-F]{24}$");
console.log(checkForValidMongoDbID.test(firstUserID)); // true
console.log(checkForValidMongoDbID.test(secondUserID)); // false

Answer 6

The simplest way to check if the string is a valid Mongo ObjectId is using mongodb module.

const ObjectID = require('mongodb').ObjectID;

if(ObjectID.isValid(777777777777777)){
   console.log("Valid ObjectID")
}