what's the purpose of line_allocated_event for redis? #70
Description
Hello, thanks for all the resources you provided in the book, helping me tremendously to understand what a clean architecture could look like in python world. Just have a quick question about this line in end-to-end test:
**subscription = redis_client.subscribe_to("line_allocated")**
what's line_allocated channel needed for? I could see that the message is getting published to "change_batch_quantity" channel but we are subscribed to a different channel but somehow still able to read the messages that come from change_batch_quantity. I might be missing something easy to understand as i don't have a lot of experience with redis pubsub. I thought the channel names should have been same for them to exchange messages. Regardless of it, the tests pass so it seems like i'm missing something here. Thank you
@pytest.mark.usefixtures("postgres_db")
@pytest.mark.usefixtures("restart_api")
@pytest.mark.usefixtures("restart_redis_pubsub")
def test_change_batch_quantity_leading_to_reallocation():
# start with two batches and an order allocated to one of them
orderid, sku = random_orderid(), random_sku()
earlier_batch, later_batch = random_batchref("old"), random_batchref("newer")
api_client.post_to_add_batch(earlier_batch, sku, qty=10, eta="2011-01-01")
api_client.post_to_add_batch(later_batch, sku, qty=10, eta="2011-01-02")
r = api_client.post_to_allocate(orderid, sku, 10)
assert r.ok
response = api_client.get_allocation(orderid)
assert response.json()[0]["batchref"] == earlier_batch
**subscription = redis_client.subscribe_to("line_allocated")**
# change quantity on allocated batch so it's less than our order
redis_client.publish_message(
"change_batch_quantity",
{"batchref": earlier_batch, "qty": 5},
)
# wait until we see a message saying the order has been reallocated
messages = []
for attempt in Retrying(stop=stop_after_delay(3), reraise=True):
with attempt:
message = subscription.get_message(timeout=1)
if message:
messages.append(message)
print(messages)
data = json.loads(messages[-1]["data"])
assert data["orderid"] == orderid
assert data["batchref"] == later_batch