public void WhenInstantiated_ThenShouldBeOfCorrectType()
    {
        var handler = new GetCustomersHandler(_repositoryMock.Object);

        Assert.NotNull(handler);
        Assert.IsType <GetCustomersHandler>(handler);
    }
    public async Task WhenRetrievingEntities_ThenAllEntitiesShouldBeReturned()
    {
        _repositoryMock.Setup(x => x.GetAsync())
        .ReturnsAsync(new List <Customer>
        {
            _mapper.Map <Customer>(Customers.Customer1),
            _mapper.Map <Customer>(Customers.Customer2),
            _mapper.Map <Customer>(Customers.Customer3)
        });

        var handler = new GetCustomersHandler(_repositoryMock.Object);

        var result = await handler.Handle(new GetCustomers(), default);

        Assert.Collection(result,
                          c => Assert.Equal(CustomerViews.Customer1.Id, c.Id),
                          c => Assert.Equal(CustomerViews.Customer2.Id, c.Id),
                          c => Assert.Equal(CustomerViews.Customer3.Id, c.Id));
    }