from delta_barth.analysis import forecast as fc


def test_sales_per_customer_success(sales_data):
    customer_id = 1133
    err, res = fc.sales_per_customer(sales_data, customer_id)

    assert err == 0
    assert res is not None


def test_sales_per_customer_too_few_data_points(sales_data):
    customer_id = 1000
    err, res = fc.sales_per_customer(sales_data, customer_id)

    assert err == 1
    assert res is None