Normal Nigerian number should be 10 digits long excluding country code

[Sirneij]

I am currently faced with the issue of validating Nigerian numbers. Normally, a typical Nigerian number is +234 XXX XXX XXXX or 0XX XXX XXX XX and when I test the formatted number against this regex r'^(0|\+234)[0-9]{10}', I always get this assertion error

AssertionError: Lists differ: [ErrorDetail(string=*Enter a valid phone number.', code='invalid')] != ['... phone number cannot be the same as your phone number.']

My settings.py has PHONENUMBER_DEFAULT_REGION = 'NG', and I tested my regex against the return value of phonenumbers.format_number( phonenumbers.parse(str(value), settings.PHONENUMBER_DEFAULT_REGION), phonenumbers.PhoneNumberFormat.E164 )

[francoisfreitag]

Hi,
It’s hard to see where the issue is without more details about what you are trying to achieve. Can you give a small code that allows reproducing the issue?
Also, can you access the entire error message?

It may be that the phone number your are using is not actually correct, despite being correctly formatted. Perhaps try to construct it directly with the phonenumbers library:

>>> phonenumbers.is_valid_number(
...     phonenumbers.parse("+2341234567", "NG")
... )
True

However:

>>> phonenumbers.is_valid_number(
...     phonenumbers.parse("+2340000000", "NG")
... )
False

[Sirneij]

Thank you @francoisfreitag . I already fixed the issue.

[Sirneij]

I am forced to reopen this issue.

Let me be more elaborate.

I have a serializer that tries to validate input phone number. From the input, I get the value inputted and format it using:

formatted_number = phonenumbers.format_number(
            phonenumbers.parse(str(value), 'NG'), phonenumbers.PhoneNumberFormat.E164
        )

Then, as part of the validation, I created a regex and searches the formatted number for a conformity with my regex. If it doesn't, I want a ValidationError to be raised:

nigeria_phone_number_pattern = r'^(0|\+234)[0-9]{10}'
        if not bool(re.search(nigeria_phone_number_pattern, formatted_number)):
            raise serializers.ValidationError(detail='Enter a valid phone number. Shorter length.')

When I test this serializer, with an input number that doesn't match the regex, I get the following error:

self.assertEqual(
E   AssertionError: Lists differ: [ErrorDetail(string='Enter a valid phone number.', code='invalid')] != ['Enter a valid phone number. Shorter length.']
E   
E   First differing element 0:
E   ErrorDetail(string='Enter a valid phone number.', code='invalid')
E   'Enter a valid phone number. Shorter length.'
E   
E   - [ErrorDetail(string='Enter a valid phone number.', code='invalid')]
E   + ['Enter a valid phone number. Shorter length.'] : Invalid request parameters.

Why this?

[francoisfreitag]

The input value is converted from a string to a PhoneNumber python object by the serializer field, then verified for validity:

django-phonenumber-field/phonenumber_field/serializerfields.py

Lines 12 to 14 in 687f009

	phone_number = to_python(data)
	if phone_number and not phone_number.is_valid():
	raise ValidationError(self.error_messages["invalid"])

That verification occurs before your custom validation kicks in, which is why you are seeing the library error message and not yours.
https://www.django-rest-framework.org/api-guide/fields/#custom-fields documents to_internal_value as follows:

The .to_internal_value() method is called to restore a primitive datatype into its internal python representation. This method should raise a serializers.ValidationError if the data is invalid.

[Sirneij]

Thanks for that. How can I ensure my test passes with my custom error raised?

[francoisfreitag]

Maybe supply a valid phone number that does not match your regular expression?

[Sirneij]

I have done that. However, test coverage is lower than the threshold (100%) because of that line. It's saying that custom validation error hasn't been covered.

[francoisfreitag]

If the coverage says your line is not executed, there’s likely something wrong in your test. Re-read it carefully or use a debugger to step through the execution and understand why your line is not executed.

[Sirneij]

I have fixed it. I'll provide the detail soon

[Sirneij]

What I did was: in my test, I put a number that returns True with phonenumbers.is_valid_number() but False with my regex. This ensures that my tests passed and my custom validation error was executed in that regard.