market/trading/tests/test_models.py

from django.test import TestCase
from trading.models import User, Commodity, TxRequest, BalanceError


class TestTransactions(TestCase):
    def test_tx_requests(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")

        # Create test commodity for user1
        com1 = Commodity(created_by=user1, in_circulation=1000, name="test1", symbol="TEST1")
        com1.save()

        # Create test commodity for user2
        com2 = Commodity(created_by=user2, in_circulation=1000, name="test2", symbol="TEST2")
        com2.save()

        # Create TX request
        req1 = TxRequest.open(user1, user2, com1, com2, 10, 10)

        # Confirm balances
        self.assertEqual(user1.balance_of(com1), 990)
        self.assertEqual(user1.balance_of(com2), 0)
        self.assertEqual(user2.balance_of(com1), 0)
        self.assertEqual(user2.balance_of(com2), 1000)

        # Accept TX request
        req1.accept()

        # Confirm balances
        self.assertEqual(user1.balance_of(com1), 990)
        self.assertEqual(user1.balance_of(com2), 10)
        self.assertEqual(user2.balance_of(com1), 10)
        self.assertEqual(user2.balance_of(com2), 990)

        # Create TX request 
        req2 = TxRequest.open(user2, user1, com2, com1, 10, 10)

        # Confirm balances
        self.assertEqual(user1.balance_of(com1), 990)
        self.assertEqual(user1.balance_of(com2), 10)
        self.assertEqual(user2.balance_of(com1), 10)
        self.assertEqual(user2.balance_of(com2), 980)

        # Decline TX request
        req2.decline()

        # Confirm balances
        self.assertEqual(user1.balance_of(com1), 990)
        self.assertEqual(user1.balance_of(com2), 10)
        self.assertEqual(user2.balance_of(com1), 10)
        self.assertEqual(user2.balance_of(com2), 990)

        # Ensure assertions on already created TXs
        with self.assertRaises(AssertionError):
            req1.accept()
        with self.assertRaises(AssertionError):
            req1.decline()
        with self.assertRaises(AssertionError):
            req2.accept()
        with self.assertRaises(AssertionError):
            req2.decline()

        # Balance checking
        # Ensure whoever opens the request has the balance available
        with self.assertRaises(BalanceError):
            TxRequest.open(user1, user2, com2, com1, 100, 100)

        # Ensure whoever tries to accept the request has the balance available
        req3 = TxRequest.open(user1, user2, com2, com1, 10, 100)
        with self.assertRaises(BalanceError):
            req3.accept()

        # And make sure you can still decline it after failing to accept it.
        req3.decline()


class TestCommodities(TestCase):
    def test_commodity_stats(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")

        # Create test commodity for user1
        com1 = Commodity(created_by=user1, in_circulation=1000, name="test1", symbol="TEST1")
        com1.save()

        # Create test commodity for user2
        com2 = Commodity(created_by=user2, in_circulation=1000, name="test2", symbol="TEST2")
        com2.save()

        # Ensure stats are correct
        self.assertEqual(com1.amount_pending, 0)
        self.assertEqual(com2.amount_pending, 0)
        self.assertEqual(com1.trading_volume(), 0)
        self.assertEqual(com2.trading_volume(), 0)
        self.assertEqual(com1.market_spread, 1)
        self.assertEqual(com2.market_spread, 1)

        # Create TX request
        req1 = TxRequest.open(user1, user2, com1, com2, 10, 100)

        # Ensure trading volume is correct
        self.assertEqual(com1.amount_pending, 10)
        self.assertEqual(com2.amount_pending, 0)
        self.assertEqual(com1.trading_volume(), 0)
        self.assertEqual(com2.trading_volume(), 0)
        self.assertEqual(com1.market_spread, 1)
        self.assertEqual(com2.market_spread, 1)

        # Accept trade
        req1.accept()

        # Ensure amount pending is correct
        self.assertEqual(com1.amount_pending, 0)
        self.assertEqual(com2.amount_pending, 0)
        self.assertEqual(com1.trading_volume(), 10)
        self.assertEqual(com2.trading_volume(), 100)
        self.assertEqual(com1.market_spread, 2)
        self.assertEqual(com2.market_spread, 2)