public void Trade_NoMoney_CannotBuyGoodStock() { // Arrange _trader.Balance = 0; _mockBroker.GetPrice("AAPL") .Returns(100); _mockSignal.Assess() .Returns(new Assessment { Recommendation = 1, Symbol = "AAPL" }); // Act _trader.Register(_mockSignal); _trader.Trade(); // Assert _mockBroker.DidNotReceive().Buy(Arg.Any <string>(), Arg.Any <int>()); _mockPortfolio.DidNotReceive().Add(Arg.Any <string>(), Arg.Any <int>()); }