Initial commit

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

tests/test_models.py

@@ -0,0 +1,26 @@
+from django.test import TestCase
+from trading.models import User, Commodity, Tx, BalanceError
+
+
+class TestTransactions(TestCase):
+    def test_user_balances(self):
+        # Create users
+        user1 = User.objects.create_user(username="test1", email="test1@test.test")
+        user2 = User.objects.create_user(username="test2", email="test2@test.test")
+
+        commodity = Commodity(created_by=user1, in_circulation=1000, name="commodity")
+        commodity.save()
+
+        self.assertEqual(user1.balances(), {commodity: 1000})
+        self.assertEqual(user2.balances(), {})
+
+        Tx(source=user1, dest=user2, amount=100, commodity=commodity).save()
+
+        self.assertEqual(user1.balances(), {commodity: 900})
+        self.assertEqual(user2.balances(), {commodity: 100})
+
+        with self.assertRaises(BalanceError):
+            Tx(source=user2, dest=user1, amount=1000, commodity=commodity).save()
+
+        self.assertEqual(user1.balances(), {commodity: 900})
+        self.assertEqual(user2.balances(), {commodity: 100})