_regex filter matching empty string fails in joiValidationErrorItemToErrorExtensions

[hanneskuettner]

Describe the Bug

When using a _regex filter that is valid in case of an empty string ^$, the conversion from Joi to Directus error fails, as strings are not allowed to be empty in Joi by default¹, which generates the error type 'string.empty' which is not accounted for in the conversion. We would have to explicitly allow empty strings in the default string schema in case of matching a regex, e.g. .allow('').

I'd like to discuss if it makes sense to allow matching empty strings in the _regexp filter or if this can result in breaking changes.

To Reproduce

• Create a string field with Save as empty string
• Set validation to Matches RegExp with the RegExp ^$|foo
• Create a new item with value foo and save the value
• Edit the item, remove the value and save
• See error message

Directus Version

v10.10.7

Hosting Strategy

Self-Hosted (Docker Image)

Footnotes

1. https://github.com/hapijs/joi/blob/master/API.md#string ↩