From c17b558d142a124e4d3ac18e4136bb92c66c4323 Mon Sep 17 00:00:00 2001
From: Bastiaan Welmers <bastiaan@welmers.net>
Date: Thu, 21 May 2020 19:34:02 +0200
Subject: [PATCH] Ability to generate unique fields in factories

---
 tests/videodinges/factories.py                | 23 +++++++++++++--
 .../test_factories/test_transcoding.py        |  2 +-
 .../videodinges/test_factories/test_video.py  | 29 +++++++++++++++++--
 tests/videodinges/views/test_video.py         |  2 +-
 4 files changed, 49 insertions(+), 7 deletions(-)

diff --git a/tests/videodinges/factories.py b/tests/videodinges/factories.py
index 3f577b2..3196d43 100644
--- a/tests/videodinges/factories.py
+++ b/tests/videodinges/factories.py
@@ -1,4 +1,5 @@
 """ Module generating useful models in 1 place """
+from inspect import signature
 from typing import Type, TypeVar
 
 from django.core.files.uploadedfile import SimpleUploadedFile
@@ -11,7 +12,11 @@ T = TypeVar('T', bound=django.db.models.Model)
 
 def create(model: Type[T], **kwargs) -> T:
 	if model is models.Video:
-		return _create_with_defaults(models.Video, kwargs, title='Title', slug='slug', description='Description')
+		return _create_with_defaults(models.Video, kwargs,
+			title=lambda x: 'Title {}'.format(x),
+			slug=lambda x: 'slug-{}'.format(x),
+			description=lambda x: 'Description {}'.format(x),
+		)
 
 	if model is models.Transcoding:
 		def url():
@@ -38,6 +43,9 @@ def _create_with_defaults(model: Type[T], kwargs: dict, **defaults) -> T:
 		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.
 
+		When a lambda requires an argument, the primary key of the to be created object
+		will be provided to that argument. This is useful for generating unique fields.
+
 		: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
@@ -45,6 +53,17 @@ def _create_with_defaults(model: Type[T], kwargs: dict, **defaults) -> T:
 
 	for k, v in defaults.items():
 		if callable(v) and not k in kwargs:
-			defaults[k] = v()
+			if len(signature(v).parameters) == 1:
+				result = v(_next_pk(model))
+			else:
+				result = v()
+			defaults[k] = result
 
 	return model.objects.create(**{**defaults, **kwargs})
+
+
+def _next_pk(model: Type[T]) -> int:
+	try:
+		return model.objects.order_by('-pk').first().pk + 1
+	except AttributeError:
+		return 1
diff --git a/tests/videodinges/test_factories/test_transcoding.py b/tests/videodinges/test_factories/test_transcoding.py
index 4e43b78..0f86df4 100644
--- a/tests/videodinges/test_factories/test_transcoding.py
+++ b/tests/videodinges/test_factories/test_transcoding.py
@@ -8,7 +8,7 @@ from tests.videodinges import factories, UploadMixin
 class TranscodingTestCase(TestCase):
 	def test_factory_returns_model(self):
 		transcoding = factories.create(Transcoding)
-		self.assertEqual(transcoding.video.slug, 'slug')
+		self.assertEqual(transcoding.video.slug, 'slug-1')
 		self.assertEqual(transcoding.quality, '360p')
 		self.assertEqual(transcoding.type, 'video/webm')
 		self.assertEqual(transcoding.url, 'https://some_url')
diff --git a/tests/videodinges/test_factories/test_video.py b/tests/videodinges/test_factories/test_video.py
index 3252a5e..ec4b957 100644
--- a/tests/videodinges/test_factories/test_video.py
+++ b/tests/videodinges/test_factories/test_video.py
@@ -6,8 +6,31 @@ from datetime import datetime
 class VideoTestCase(TestCase):
 	def test_factory_returns_model(self):
 		video = factories.create(Video)
-		self.assertEqual(video.slug, 'slug')
-		self.assertEqual(video.title, 'Title')
-		self.assertEqual(video.description, 'Description')
+		self.assertEqual(video.slug, 'slug-1')
+		self.assertEqual(video.title, 'Title 1')
+		self.assertEqual(video.description, 'Description 1')
 		self.assertIsInstance(video.created_at, datetime)
 		self.assertIsInstance(video.updated_at, datetime)
+
+	def test_factory_can_create_multiple_models(self):
+		video1 = factories.create(Video)
+		video2 = factories.create(Video)
+		video3 = factories.create(Video)
+
+		self.assertEqual(video1.slug, 'slug-1')
+		self.assertEqual(video1.title, 'Title 1')
+		self.assertEqual(video1.description, 'Description 1')
+		self.assertIsInstance(video1.created_at, datetime)
+		self.assertIsInstance(video1.updated_at, datetime)
+
+		self.assertEqual(video2.slug, 'slug-2')
+		self.assertEqual(video2.title, 'Title 2')
+		self.assertEqual(video2.description, 'Description 2')
+		self.assertIsInstance(video2.created_at, datetime)
+		self.assertIsInstance(video2.updated_at, datetime)
+
+		self.assertEqual(video3.slug, 'slug-3')
+		self.assertEqual(video3.title, 'Title 3')
+		self.assertEqual(video3.description, 'Description 3')
+		self.assertIsInstance(video3.created_at, datetime)
+		self.assertIsInstance(video3.updated_at, datetime)
diff --git a/tests/videodinges/views/test_video.py b/tests/videodinges/views/test_video.py
index 684b60a..aef91b8 100644
--- a/tests/videodinges/views/test_video.py
+++ b/tests/videodinges/views/test_video.py
@@ -70,7 +70,7 @@ class VideoTestCase(UploadMixin, TestCase):
 
 		self.assertInHTML('<h1>Vid 1</h1>', content)
 
-		self.assertInHTML('<p>Description</p>', content)
+		self.assertInHTML('<p>Description 1</p>', content)
 
 		self.assertInHTML('<strong>480p versie</strong>', content)