Description

I'd like to propose a few steps to improve the validation constraints:

• Deprecate empty strings ("") currently happily passing in string constraints (e.g. Email)
  • https://docs.jboss.org/hibernate/stable/beanvalidation/api/javax/validation/constraints/Email.html
• Deprecate non string values in NotBlank / Blank and 'whitespaced' strings passing (" ")
  • https://docs.jboss.org/hibernate/stable/beanvalidation/api/javax/validation/constraints/NotBlank.html
  • allow for null (NotBlank validator should not invalidate null values #27876)
• Consider NotEmpty / Empty as the current NotBlank / Blank constraints
  • https://docs.jboss.org/hibernate/stable/beanvalidation/api/javax/validation/constraints/NotEmpty.html
  • I dont think we should add these (but favor specific constraints) as empty in PHP is different as described above (ints, bools, etc). Not sure we should follow either one :) thus possible confusion

If this happens we'd do simply

• @Email
• @NotNull @Email
• @NotNull @Length(min=3) @NotBlank
• @NotNull @NotBlank
• @Type(array) @Count(3)

Thoughts?