diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py index f21a6df7f7..50d22bef0c 100644 --- a/django/db/models/fields/__init__.py +++ b/django/db/models/fields/__init__.py @@ -244,10 +244,10 @@ class Field(RegisterLookupMixin): if not self.choices: return [] - def is_value(value): - return isinstance(value, (str, Promise)) or not is_iterable(value) + def is_value(value, accept_promise=True): + return isinstance(value, (str, Promise) if accept_promise else str) or not is_iterable(value) - if is_value(self.choices): + if is_value(self.choices, accept_promise=False): return [ checks.Error( "'choices' must be an iterable (e.g., a list or tuple).", diff --git a/tests/invalid_models_tests/test_ordinary_fields.py b/tests/invalid_models_tests/test_ordinary_fields.py index fb222edad3..546c16a976 100644 --- a/tests/invalid_models_tests/test_ordinary_fields.py +++ b/tests/invalid_models_tests/test_ordinary_fields.py @@ -4,6 +4,7 @@ from django.core.checks import Error, Warning as DjangoWarning from django.db import connection, models from django.test import SimpleTestCase, TestCase, skipIfDBFeature from django.test.utils import isolate_apps, override_settings +from django.utils.functional import lazy from django.utils.timezone import now from django.utils.translation import gettext_lazy as _ @@ -188,6 +189,12 @@ class CharFieldTests(TestCase): self.assertEqual(Model._meta.get_field('field').check(), []) + def test_lazy_choices(self): + class Model(models.Model): + field = models.CharField(max_length=10, choices=lazy(lambda: [[1, '1'], [2, '2']], tuple)()) + + self.assertEqual(Model._meta.get_field('field').check(), []) + def test_choices_named_group(self): class Model(models.Model): field = models.CharField(