Reduce get next question queries

questions/models.py

@@ -27,6 +27,18 @@ class Meta:
         abstract = True
 
 
+class QuestionManager(models.Manager):
+
+    def get_user_questions(self, user):
+
+        questions = self.filter(
+            tag__usertag__user=user,
+            tag__usertag__enabled=True
+        )
+
+        return questions
+
+
 class Question(CreatedBy):
     question = models.TextField()
     answer = models.ForeignKey('Answer', null=True, blank=True)
@@ -36,6 +48,7 @@ class Question(CreatedBy):
     # tag_set
     # user
     # user_set
+    objects = QuestionManager()
 
     def __unicode__(self):
         return '<Question id=[%s] question=[%s] datetime_added=[%s]>' % (self.id, self.question, self.datetime_added)

questions/tests/test_get_next_question.py

@@ -0,0 +1,77 @@
+from django.test import TestCase
+
+from django.db import connection
+from django.test.utils import override_settings
+from emailusername.models import User
+
+from questions import models
+from questions.views import _get_next_question
+from questions.views import NextQuestion
+
+
+class TestGetNextQuestion(TestCase):
+
+    def setUp(self):
+        # Create a user
+        self.PASSWORD = 'p'
+        self.USERNAME = 'foo@bar.com'
+        self.user = User(email=self.USERNAME)
+        self.user.set_password(self.PASSWORD)
+        self.user.save()
+
+    def _assign_question_to_user(self, user, question):
+        tag = models.Tag.objects.create(name='faketag')
+
+        models.UserTag.objects.create(
+            tag=tag,
+            user=user,
+            enabled=True
+        )
+        models.QuestionTag.objects.create(
+            tag=tag,
+            question=question,
+            enabled=True
+        )
+
+        return tag
+
+    def test_user_with_no_questions(self):
+        next_question = _get_next_question(self.user)
+
+        self.assertIsInstance(next_question, NextQuestion)
+        self.assertIsNone(next_question.question)
+
+    @override_settings(DEBUG=True)
+    def test_user_with_one_question(self):
+        question = models.Question.objects.create(
+            question='fakebar',
+        )
+        self._assign_question_to_user(self.user, question)
+
+        next_question = _get_next_question(self.user)
+
+        self.assertIsInstance(next_question, NextQuestion)
+        self.assertIsNotNone(next_question.question)
+        self.assertEqual(len(connection.queries), 8)
+
+        questions = models.Question.objects.get_user_questions(self.user)
+
+        self.assertEqual(questions.count(), 1)
+
+    @override_settings(DEBUG=True)
+    def test_user_with_ten_questions(self):
+        for i in range(10):
+            question = models.Question.objects.create(
+                question='fakebar',
+            )
+            self._assign_question_to_user(self.user, question)
+
+        next_question = _get_next_question(self.user)
+
+        self.assertIsInstance(next_question, NextQuestion)
+        self.assertIsNotNone(next_question.question)
+        self.assertEqual(len(connection.queries), 53)
+
+        questions = models.Question.objects.get_user_questions(self.user)
+
+        self.assertEqual(questions.count(), 10)

questions/tests.py → questions/tests/tests.py

@@ -10,7 +10,7 @@
 
 from emailusername.models import User
 from questions import forms, models
-from questions.test_helpers import FuzzyInt
+from questions.tests.test_helpers import FuzzyInt
 from questions.views import _get_next_question
 
 # By default, LiveServerTestCase uses port 8081.