Validate array contains specific value using joi

Question

I'm looking for a way to validate that an array contains a required value using joi.
Found these issues online - #1, #2, but none of them has a definitive answer.
I tried several stuff but they doesn't seem to work, like:
joi.array().items(joi.string().allow('required-string').required()), joi.array().items(joi.string().label('required-string').required()), joi.array().items(joi.string().valid('required-string'))

This is what I'm trying to achieve:

Accepted:

['required-string'], ['required-string', 'other'], ['other','required-string'], ['other',...,'required-string',....,'more-other']

Denied:

[], ['other'], [null], etc..

Answer 1

You can use array.items by listing all allowed types. If a given type is .required() then there must be a matching item in the array: joi API reference

joi.array().items(joi.string().valid('required-string').required(), joi.string())