add common faker class with util methods

scipost_django/common/faker.py

+__copyright__ = "Copyright © Stichting SciPost (SciPost Foundation)"
+__license__ = "AGPL v3"
+
+import random
+from datetime import datetime, timedelta
+from django.utils.timezone import make_aware
+
+import factory
+from faker import Faker
+from faker.providers import BaseProvider
+
+
+class LazyRandEnum(factory.LazyAttribute):
+    """
+    Define a lazy attribute that takes a random value from a Django enum.
+    The Django enum is a list of two-tuples, where the first element is the
+    value and the second element is the human-readable name.
+    The attribute evalutates to the value, not the human-readable name.
+    """
+
+    def __init__(self, enum, *args, **kwargs):
+        self.enum = enum
+        super().__init__(function=self._random_choice_from_enum, *args, **kwargs)
+
+    def _random_choice_from_enum(self, _):
+        return random.choice(self.enum)[0]
+
+
+class LazyAwareDate(factory.LazyAttribute):
+    """
+    Define a lazy attribute that returns a timezone-aware random date from a Faker provider.
+    """
+
+    def __init__(self, provider, *args, **kwargs):
+        self.provider = provider
+
+        super().__init__(function=lambda _: self.generate_aware_date(*args, **kwargs))
+
+    def _generate_date(self, *args, **kwargs):
+        return getattr(fake, self.provider)(*args, **kwargs)
+
+    @staticmethod
+    def _convert_to_datetime(date):
+        return datetime.combine(date, datetime.min.time())
+
+    def generate_aware_date(self, *args, **kwargs):
+        return make_aware(
+            self._convert_to_datetime(self._generate_date(*args, **kwargs))
+        )
+
+
+class DurationProvider(BaseProvider):
+    def duration(self):
+        seconds = self.random_int(min=0, max=86400)
+        return timedelta(seconds=seconds)
+
+
+fake = Faker()
+fake.add_provider(DurationProvider)