Issue with ".format" and number restriction

[david-unergie]

Context

• node version: v6.9.2
• joi version: v10.6.0 / v11.4.0 / v12.0.0 / v13.7.0 / v14.3.0
• environment (node, browser): node
• used with (hapi, standalone, ...): standalone
• any other relevant information: joi-date-extensions v1.2.0

What are you trying to achieve or the steps to reproduce ?

joi.date() accepts a valid date string or a number of milliseconds. Using .format() should accept a valid date string, and should reject number in this case.

Working with joi v9.2.0:

const joi = require('joi')
joi.date().format('YYYY-MM-DD').raw().validate(12)
// => error "value" must be a string with one of the following formats YYYY-MM-DD

Failing with v10.6.0 / v11.4.0 / v12.0.0 / v13.7.0 / v14.3.0:

const joi = require('joi').extend(require('joi-date-extensions'))
joi.date().format('YYYY-MM-DD').raw().validate(12)
// => no error, return Number(12)

Which result you had ?

A number

What did you expect ?

An error: "value" must be a string with one of the following formats [YYYY-MM-DD]

[hueniverse]

format() only applies to strings. I would argue the old behavior was incorrect.

[david-unergie]

In this case @hueniverse, how to implement a "joi.date()" in order to allow string only?

[hueniverse]

Use Joi.string() with a regex pattern. There is no option to not allow numbers as input.

[david-unergie]

But in this case, there is no validation about the date consistency. For example, "2019-13-48" will be accepted…

[hueniverse]

Like I said, this is not a supported use case. In v16 you can write a custom function validator that checks helpers.original to be a string.

[david-unergie]

Ok. I just wanted to point out that the old behaviour may not be so bad. Thanks.

[shadrech]

I concur with @david-unergie. Maybe add a new field which forces input to only be a string? Old behaviour is far more logical as it abides by the set format(...) check