ThrowIfCustomerAlreadyReg.cs

[Fact]
public async Task ShouldThrowIfCustomerAlreadyRegistered()
{
	var email = "customer@gmail.com";
	var customerRepositoryStub = CreateRepositoryWith(TestCustomerWith(email));
	
	var testCustomerRegistrationRequest = new CustomerRegistrationRequest(
		email, 
		dateOfBirth: new DateTime(1975, 2, 21), 
		firstName: "Joe", 
		lastName: "Bloggs");		
	
	// Create the system under test with a stub and a dummy	
	var useCase = new CustomerRegistrationUseCase(
		customerRepositoryStub, 
		new Mock<IEventBus>().Object);
		
	await Assert.ThrowsAsync<CustomerAlreadyExists>(()=> 
        useCase.RegisterCustomer(testCustomerRegistrationRequest));
}