I'd like to check for a correct ObjectID to continue my code. I'am on NodeJS and I don't want to get the error:

Error: Argument passed in must be a single String of 12 bytes or a string of 24 hex characters

Actually I got those tests:

if (!user.id || !user.id.match("/^[0-9a-fA-f]{24}$") || !typeof(user.id) === 'string') {
        console.log("user id is required !")
        return callback("user id is required !")
    }

For string of 24 hex characters I got this regex :

!user.id.match("/^[0-9a-fA-f]{24}$")

And I am searching for check if it is a string of 12 bytes :

!typeof(user.id) === 'string'

How should I add the verification for the 12 bytes?

Any idea please?

I'd like to check for a correct ObjectID to continue my code. I'am on NodeJS and I don't want to get the error:

Error: Argument passed in must be a single String of 12 bytes or a string of 24 hex characters

Actually I got those tests:

if (!user.id || !user.id.match("/^[0-9a-fA-f]{24}$") || !typeof(user.id) === 'string') {
        console.log("user id is required !")
        return callback("user id is required !")
    }

For string of 24 hex characters I got this regex :

!user.id.match("/^[0-9a-fA-f]{24}$")

And I am searching for check if it is a string of 12 bytes :

!typeof(user.id) === 'string'

How should I add the verification for the 12 bytes?

Any idea please?

• javascript
• node.js
• regex
• string
• mongodb

• Check out github./Automattic/mongoose/issues/1959 – chridam Commented Sep 26, 2017 at 9:07
• Are you really asking us "how do you check a string is 12 characters long"? – Tom Lord Commented Sep 26, 2017 at 9:09
• I am asking for both in a same test @TomLord – Cupkek05 Commented Sep 26, 2017 at 9:10
• 2 @Cupkek05 ^(.{12}|[0-9a-fA-f]{24})$??... – Tom Lord Commented Sep 26, 2017 at 9:12
• @TomLord, thanks, it works, sorry I am new with regex... It is not so simple to understand :/ – Cupkek05 Commented Sep 26, 2017 at 9:15

2 Answers 2

With NodeJS if you are using :

const objectID = require('mongodb').objectID

You could simply test your ObjectID like that :

ObjectID.isValid(yourobjectid)

It will return true if it is valid and false if it is not.

From what I see you can pass as an Id any string you want. You should probably turn it into Hexadecimal string first (http://forums.devshed./javascript-development-115/convert-string-hex-674138.html)

function toHex(str) {
   var hex = '';
   for(var i=0;i<str.length;i++) {
      hex += ''+str.charCodeAt(i).toString(16);
   }
   return hex;
}

and then create an ObjectId from the Hexadecimal string the way it is suggested from the mongoDB Documentation (https://docs.mongodb./manual/reference/method/ObjectId/)

Specify a Hexadecimal string

To generate a new ObjectId using ObjectId() with a unique hexadecimal string:

y = ObjectId("507f191e810c19729de860ea")