Allow date strings in gt(e)/lt(e)/between in validation step

[rijkvanzanten]

Preflight Checklist

• I have completed all Troubleshooting Steps.
• I'm on the latest version of Directus.
• There's no other issue that already describes my problem.

Describe the Bug

Currently, the generate joi function relies on Joi's number type to create the validation rules:

directus/packages/shared/src/utils/generate-joi.ts

Lines 165 to 171 in 67215b1

	if (operator === '_lt') {
	schema[key] = getNumberSchema().less(Number(compareValue));
	}
	if (operator === '_lte') {
	schema[key] = getNumberSchema().max(Number(compareValue));
	}

This fails when the value to compare against is a string (like 2021-09-21) with Error: limit must be a number or reference.

This is different from permissions, where the filter is applied as a query in SQL, which does accept this difference.

To Reproduce

Try using dates in validation with a gte/between etc type field, for example:

{
    "date": {
        "_between": [
            "2020-09-10",
            "2021-09-15"
        ]
    }
}

What version of Directus are you using?

v9.0.0-rc.93

What version of Node.js are you using?

16.4

What database are you using?

Postgres

What browser are you using?

Safari

What operating system are you using?

macOS

How are you deploying Directus?

Locally

[rijkvanzanten]

We might be able to solve for this by checking if the value is a number first, and if it isn't default to a "date", as numbers and dates are the only two types you can use with greater than / between