Consider adding a "nullOrNotBlank" method to RequestValidator

[clone1612]

The OpenAPI generator plugin doesn't add @NotBlank/@NotEmpty annotations to the generated interfaces: https://stackoverflow.com/questions/77515177/openapi-generator-do-not-insert-notblank-annotation-for-string

A workaround is to add x-field-extra-annotation: "@jakarta.validation.constraints.NotBlank" hints to the schema, but that's not exactly clean. As not all parameters have a regex we can use to enforce certain content we sometimes have to check that in our code.

The idea would be to add a nullOrNotBlank(Input<String>... inputs) method to the RequestValidator that allows us to integrate that check with others in the validator (without resorting to the more verbose .custom(...) method). Maybe it's a bit too specific? What do you think?

[jpraet]

The RequestValidator is mainly meant for validations that cannot be enforced through the openapi schema.

• for a non-empty string, you can define minLength: 1 in the openapi schema
• for a non-blank string, you can define pattern: \S in the openapi schema