specify field name instead of "value"

Question

I have to validate value by value instead of passing in a whole schema for multiple values. Based on the docs for single value validation from here

https://hapi.dev/module/joi/

and this sample code

const validator: AnySchema = Joi.string().valid('foo', 'bar').required();
const validationResult: ValidationResult = validator.validate('invalid');
const validationError: ValidationError = validationResult.error;

if (validationError) {
    throw validationError;
}

The code will throw an error with the following error message

ValidationError: "value" must be one of [foo, bar]

Is there an easy way I can replace "value" with a specific name? So when I want to validate environment the error message could be

ValidationError: "environment" must be one of [development, production, test]

or is that only possible when validating multiple values at once?

Christos Lytras Christos Lytras · Accepted Answer · 2020-04-14T15:15:42

There is the any.label(name) method that you can use and set a custom label that will be displayed in error messages as well:

any.label(name)

Overrides the key name in error messages.

name - the name of the key.
const schema = {
    first_name: Joi.string().label('First Name')
};

You can simply do:

const validator: AnySchema = Joi
  .string()
  .label('Foo/Bar') // Change tha label using label method
  .valid('foo', 'bar')
  .required();

const validationResult: ValidationResult = validator.validate('invalid');
const validationError: ValidationError = validationResult.error;

if (validationError) {
    throw validationError;
}

will output:

ValidationError: "Foo/Bar" must be one of [foo, bar]

specify field name instead of "value"

1 Answers