Use lambda for dependencies

so they won't be created when dependency is already provided

tests/videodinges/factories.py

@@ -14,10 +14,8 @@ def create(model: Type[T], **kwargs) -> T:
 		return _create_with_defaults(models.Video, kwargs, title='Title', slug='slug', description='Description')
 
 	if model is models.Transcoding:
-		video = create(models.Video, title='Title', slug='slug', description='Description') \
-			if 'video' not in kwargs else None
 		defaults = dict(
-			video=video,
+			video=lambda: create(models.Video),
 			quality=models.qualities[0].name,
 			type=str(models.transcoding_types[0]),
 		)
@@ -36,8 +34,16 @@ def create(model: Type[T], **kwargs) -> T:
 def _create_with_defaults(model: Type[T], kwargs: dict, **defaults) -> T:
 	"""
 		Return created django model instance.
+		When providing lambda as default item, the result of the lambda will be taken.
+		The lambda will ONLY be executed when not provided in kwargs.
+
 		:param model: django model to create
 		:param kwargs: keyword arguments to fill the model
 		:param defaults: default keyword arguments to use when not mentioned in kwargs
 	"""
+
+	for k, v in defaults.items():
+		if callable(v) and not k in kwargs:
+			defaults[k] = v()
+
 	return model.objects.create(**{**defaults, **kwargs})

tests/videodinges/test_factories/test_transcoding.py

@@ -24,3 +24,14 @@ class TranscodingTestCase(TestCase):
 		self.assertEqual(transcoding.quality, '720p')
 		self.assertEqual(transcoding.type, 'video/mp4')
 		self.assertEqual(transcoding.url, 'http://another_url')
+
+	def test_does_not_create_video_when_providing_one(self):
+		transcoding = factories.create(
+			Transcoding,
+			quality='720p',
+			type='video/mp4',
+			url='http://another_url',
+			video=factories.create(Video, slug='yet-another-video-slug')
+		)
+
+		self.assertEquals(Video.objects.all().count(), 1)