How to use the optionalId function from joi

joi.optionalId is a function provided by the Joi library used for validating optional string identifiers that meet specified criteria.

How does joi.optionalId work?

joi.optionalId is a function provided by the Joi library for validating optional string identifiers that meet specified criteria. This function is often used to validate unique identifiers for database records, such as a MongoDB document ID. Under the hood, joi.optionalId returns a Joi schema object that includes rules for validating the identifier. The schema object can then be used to validate an object containing the identifier value, such as a database record. By default, joi.optionalId allows the identifier to be either a string or null. If the identifier is a string, it must meet the specified criteria, which can include a length limit, regular expression pattern, or other custom validation criteria. To use joi.optionalId, you pass the desired validation criteria as an options object to the function, such as {alphanum: true} to require that the identifier contain only alphanumeric characters. You can also specify additional validation rules, such as min or max to limit the length of the identifier. Overall, joi.optionalId provides a flexible and convenient way to validate optional string identifiers that meet specific criteria, helping to ensure that your application's data is well-formed and consistent.

Ai Example

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
const Joi = require("joi");

// Define a schema for a MongoDB document
const schema = Joi.object({
  _id: Joi.optionalId({ alphanum: true }).allow(null),
  name: Joi.string().required(),
  age: Joi.number().integer().min(0).max(120).required(),
});

// Validate a document with an optional ID
const doc1 = { _id: null, name: "John Doe", age: 30 };
const result1 = schema.validate(doc1);
console.log(result1); // Output: { value: { _id: null, name: 'John Doe', age: 30 }, error: null }

const doc2 = { _id: "1234abcd", name: "Jane Doe", age: 25 };
const result2 = schema.validate(doc2);
console.log(result2); // Output: { value: { _id: '1234abcd', name: 'Jane Doe', age: 25 }, error: null }

const doc3 = { _id: "foo!bar", name: "Bob Smith", age: 45 };
const result3 = schema.validate(doc3);
console.log(result3); // Output: { value: null, error: [Error: "_id" must only contain alpha-numeric characters] }

In this example, a Joi schema is defined for a MongoDB document with an optional _id field, a required name field, and a required age field. The _id field is validated using Joi.optionalId, with the alphanum option specified to allow only alphanumeric characters. Three different documents are then validated using the schema. doc1 has a null _id field, which is allowed by the schema. doc2 has a valid string _id field, which is also allowed by the schema. doc3 has an invalid _id field containing a non-alphanumeric character, which fails validation and returns an error. Note that joi.optionalId is a flexible function that can be customized to meet the specific needs of your application, allowing you to validate unique identifiers according to your desired criteria.