optional

Learn about the available options, methods and use cases.

You can pass any validator to this utility and make it optional. If an undefined value is received from the input, it will skip the validation and optionally return a default value.

Usage

Following is the simple usage of this validator

import e from "validator";

await e.optional(e.string())
.validate() // returns undefined

Options

Following are the available options for this validator

interface IOptionalValidatorOptions extends TBaseValidatorOptions {
    // No specific options...
}

Methods

Following are the available methods on this validator

// Set a default value
.default<DefaultInput, Validate extends boolean = false>(
    value: DefaultInput,
    options?: {
      validate?: Validate;
    },
)

Examples

Read the examples below to understand different use cases

Case 1 (Basic usage)

// Default if undefined
await e.optional(
    e.number() // Any validator is allowed
).default(null)
.validate() // returns null

Case 2 (Use with object)

await e.object({
    foo: e.optional(e.string()),
    bar: e.optional(e.number()).default(0)
})
.validate({}) // returns { bar: 0 }