little cleanup TODO in PiLog simulate()

I think I'm going to move the irc stuff into a separate project in the
future so I'm not worried about testing that one yet

pi/models.py

@@ -31,6 +31,7 @@ class PiLogManager(models.Manager):
         newest = PiLog.objects.create(simulation_x=x, simulation_y=y,
                                       total_count_inside=inside, total_count=total)
 
+        # TODO: remove the x, y return values, now that we track them in the object
         return newest, x, y
 
 
@@ -66,4 +67,4 @@ class PiLog(models.Model):
     @property
     def hit(self):
         """Return if this log entry is inside the unit circle."""
-        return math.hypot(self.simulation_x, self.simulation.y) < 1
+        return math.hypot(self.simulation_x, self.simulation_y) < 1

pi/views.py

@@ -1,12 +1,22 @@
 """Provide pi simulation results."""
-from rest_framework import viewsets
+from rest_framework.decorators import action
+from rest_framework.permissions import IsAuthenticated
+from rest_framework.response import Response
+from rest_framework.viewsets import ReadOnlyModelViewSet
 
 from pi.models import PiLog
 from pi.serializers import PiLogSerializer
 
 
-class PiLogViewSet(viewsets.ReadOnlyModelViewSet):
+class PiLogViewSet(ReadOnlyModelViewSet):
     """Provide list and detail actions for pi simulation log entries."""
 
     queryset = PiLog.objects.all()
     serializer_class = PiLogSerializer
+    permission_classes = [IsAuthenticated]
+
+    @action(detail=False, methods=['post'])
+    def simulate(self, request):
+        """Run one simulation of the pi estimator."""
+        simulation, _, _ = PiLog.objects.simulate()
+        return Response(self.get_serializer(simulation).data, 201)

tests/test_pi_models.py

@@ -0,0 +1,47 @@
+"""Test the pi models."""
+from unittest import mock
+
+from django.test import TestCase
+from django.utils.timezone import now
+
+from pi.models import PiLog
+
+
+class PiLogTest(TestCase):
+    """Test pi models."""
+
+    def test_hit_calculation(self):
+        """Test that x,y combinations are properly considered inside or outside the circle."""
+        hit_item = PiLog(simulation_x=0.0, simulation_y=0.0, total_count=0, total_count_inside=0)
+        miss_item = PiLog(simulation_x=1.0, simulation_y=1.0, total_count=0, total_count_inside=0)
+
+        self.assertTrue(hit_item.hit)
+        self.assertFalse(miss_item.hit)
+
+    def test_value_calculation(self):
+        """Test that a simulation's value of pi can be calculated."""
+        item = PiLog(simulation_x=0.0, simulation_y=0.0, total_count=1000, total_count_inside=788)
+        zero_item = PiLog(simulation_x=0.0, simulation_y=0.0, total_count=0, total_count_inside=0)
+
+        self.assertEqual(item.value, 3.152)
+        self.assertEqual(zero_item.value, 0.0)
+
+    def test_string_repr(self):
+        """Test the string repr of a simulation log entry."""
+        item = PiLog(simulation_x=0.0, simulation_y=0.0, total_count=1000, total_count_inside=788,
+                     created=now())
+
+        self.assertIn("(788/1000) @ ", str(item))
+
+    def test_simulation_inside_determination(self):
+        """Test that running a simulation passes the proper inside value."""
+        # get at least one simulation in the DB
+        original_item, _, _ = PiLog.objects.simulate()
+
+        with mock.patch('random.random', return_value=1.0):
+            miss_item, _, _ = PiLog.objects.simulate()
+        self.assertEqual(miss_item.total_count_inside, original_item.total_count_inside)
+
+        with mock.patch('random.random', return_value=0.0):
+            hit_item, _, _ = PiLog.objects.simulate()
+        self.assertGreater(hit_item.total_count_inside, original_item.total_count_inside)

tests/test_pi_views.py

@@ -0,0 +1,25 @@
+"""Test the pi package's views."""
+from django.contrib.auth.models import User
+from rest_framework.status import HTTP_201_CREATED
+from rest_framework.test import APITestCase
+
+from pi.models import PiLog
+
+
+class PiAPITest(APITestCase):
+    """Test pi DRF views."""
+
+    def setUp(self):
+        """Do pre-test stuff."""
+        self.client = self.client_class()
+        self.user = User.objects.create(username='test')
+        self.client.force_authenticate(user=self.user)
+
+    def test_simulate_creates_simulation(self):
+        """Test that the simulate action creates a log entry."""
+        self.assertEqual(PiLog.objects.count(), 0)
+
+        resp = self.client.post('/pi/api/simulations/simulate/')
+
+        self.assertEqual(resp.status_code, HTTP_201_CREATED)
+        self.assertEqual(PiLog.objects.count(), 2)      # 2 because 0 entry and the real entry