Use the default region’s format in form errors

Instead of showing an international number, use a phone number
originating from the configured PHONENUMBER_DEFAULT_REGION.

Reviewed-by: thedrow

CHANGELOG.rst

@@ -6,6 +6,7 @@ UNRELEASED
 
 * Set the default region of ``phonenumber_field.formfields.PhoneNumberField``
   to ``PHONENUMER_DEFAULT_REGION``.
+* Use PHONENUMBER_DEFAULT_REGION for example phone number in form field errors.
 * Add support for Django 4.0
 * Add Persian (farsi) translations.
 * Update uk_AR translations

phonenumber_field/formfields.py

@@ -21,8 +21,8 @@ def __init__(self, *args, region=None, **kwargs):
         self.region = region or getattr(settings, "PHONENUMBER_DEFAULT_REGION", None)
 
         if "invalid" not in self.error_messages:
-            if region:
-                number = phonenumbers.example_number(region)
+            if self.region:
+                number = phonenumbers.example_number(self.region)
                 example_number = to_python(number).as_national
                 # Translators: {example_number} is a national phone number.
                 error_message = _(

tests/test_formfields.py

@@ -1,7 +1,7 @@
 from unittest import mock
 
 from django import forms
-from django.test import SimpleTestCase
+from django.test import SimpleTestCase, override_settings
 from django.utils.functional import lazy
 
 from phonenumber_field.formfields import PhoneNumberField
@@ -20,6 +20,23 @@ class PhoneNumberForm(forms.Form):
             form.errors, {"number": ["Enter a valid phone number (e.g. +12125552368)."]}
         )
 
+    @override_settings(PHONENUMBER_DEFAULT_REGION="FR")
+    def test_error_message_uses_default_region(self):
+        class PhoneNumberForm(forms.Form):
+            number = PhoneNumberField()
+
+        form = PhoneNumberForm({"number": "invalid"})
+        self.assertIs(form.is_valid(), False)
+        self.assertEqual(
+            form.errors,
+            {
+                "number": [
+                    "Enter a valid phone number (e.g. 01 23 45 67 89) "
+                    "or a number with an international call prefix."
+                ]
+            },
+        )
+
     def test_override_error_message(self):
         class MyPhoneNumberField(PhoneNumberField):
             default_error_messages = {"invalid": "MY INVALID MESSAGE!"}