This commit:
- improves the tests to check for specific error messages, rather than just
pass/fail
- makes the error messages more human, and more suggestive of what the user
needs to do to fix the error
This field does two things:
- validates the format of the phone number
- outputs a consistent representation of the phone number
Because of this I think it’s better represented as a new field type, rather
than individual validators.
I also think that it’s better to do this without regular expression(s), because
it makes returning the specific error easier.
This commit also adds basic pass/fail test for a series of valid/invalid
phone numbers.
