I have the following model in common/models.py:
from django.db import models
from uuid import uuid4
class BaseModel(models.Model):
guid = models.UUIDField(unique=True, default=uuid.uuid4, editable=False)
class Meta:
abstract = True
In app/models.py I have the following:
from django.db import models
from common.models import BaseModel
class Entity(BaseModel):
name = models.CharField()
In tests I tried to patch uuid4 in the following ways:
def test_model_create(mocker):
# Given
mock_guid = mocker.patch("uuid.uuid4", return_value="some-guid")
# When
entity = Entity.objects.create(name="test_name")
# Then
mock_guid.assert_called_once()
assert "some-guid" == entity.guid
mock_guid.assert_called_once() returns not called. What can be the issue here?
I think the issue is that guid = models.UUIDField(unique=True, default=uuid.uuid4, editable=False) references the uuid.uuid4 function directly at parsing time. When you set up your mock, it's too late to replace this pointer.
Changing it to something like guid = models.UUIDField(unique=True, default=lambda: uuid.uuid4(), editable=False) should fix your issue, because the value is returned at runtime, and your mock will be setup properly before the function is referenced and called.