Rewrite handlers tests in terms of messagebus

Author: heykarimoff

src/allocation/service_layer/unit_of_work.py

@@ -1,7 +1,9 @@
 import abc
+from typing import Generator, Optional
 
 from allocation import config
 from allocation.adapters import repository
+from allocation.domain import events
 from sqlalchemy import create_engine
 from sqlalchemy.orm import sessionmaker
 
@@ -33,7 +35,9 @@ def commit(self):
     def rollback(self):
         self._rollback()
 
-    def collect_new_events(self):
+    def collect_new_events(
+        self,
+    ) -> Optional[Generator[events.Event, None, None]]:
         for product in self.products.seen:
             while product.events:
                 yield product.events.pop(0)

tests/e2e/test_api.py

@@ -38,7 +38,7 @@ def test_add_batch(url):
         },
     )
 
-    assert response.status_code == 201
+    assert response.status_code == 201, response.text
 
     response = requests.post(
         f"{url}/add_batch",
@@ -49,7 +49,7 @@ def test_add_batch(url):
             "eta": "2021-01-01",
         },
     )
-    assert response.status_code == 201
+    assert response.status_code == 201, response.text
 
 
 @pytest.mark.usefixtures("restart_api")
@@ -66,7 +66,7 @@ def test_returns_200_and_allocated_batch(url, post_to_add_stock):
     data = {"orderid": random_orderid(), "sku": sku, "qty": 3}
     response = requests.post(f"{url}/allocate", json=data)
 
-    assert response.status_code == 201
+    assert response.status_code == 201, response.text
     assert response.json()["batchref"] == earlybatch
 
 
@@ -82,7 +82,7 @@ def test_retuns_400_and_out_of_stock_message(url, post_to_add_stock):
     data = {"orderid": large_order, "sku": sku, "qty": 20}
     response = requests.post(f"{url}/allocate", json=data)
 
-    assert response.status_code == 400
+    assert response.status_code == 400, response.text
     assert response.json()["message"] == "Out of stock"
 
 
@@ -93,7 +93,7 @@ def test_returns_400_invalid_sku_message(url):
     data = {"orderid": orderid, "sku": unknown_sku, "qty": 20}
     response = requests.post(f"{url}/allocate", json=data)
 
-    assert response.status_code == 400
+    assert response.status_code == 400, response.text
     assert response.json()["message"] == f"Invalid sku {unknown_sku}"
 
 

tests/unit/test_handlers.py

@@ -56,7 +56,8 @@ def test_add_batch_for_new_product():
     event = events.BatchCreated(
         reference="batch1", sku="COMPLICATED-LAMP", qty=100
     )
-    handlers.add_batch(event=event, uow=uow)
+
+    messagebus.handle(event, uow)
 
     assert uow.products.get("COMPLICATED-LAMP") is not None
     product = uow.products.get("COMPLICATED-LAMP")
@@ -66,14 +67,13 @@ def test_add_batch_for_new_product():
 
 def test_add_batch_for_existing_product():
     uow = FakeUnitOfWork()
-    event1 = events.BatchCreated(
-        reference="batch1", sku="CRUNCHY-ARMCHAIR", qty=10
-    )
-    event2 = events.BatchCreated(
-        reference="batch2", sku="CRUNCHY-ARMCHAIR", qty=15
-    )
-    handlers.add_batch(event=event1, uow=uow)
-    handlers.add_batch(event=event2, uow=uow)
+    event_history = [
+        events.BatchCreated(reference="batch1", sku="CRUNCHY-ARMCHAIR", qty=10),
+        events.BatchCreated(reference="batch2", sku="CRUNCHY-ARMCHAIR", qty=15),
+    ]
+
+    for event in event_history:
+        messagebus.handle(event, uow)
 
     assert uow.products.get("CRUNCHY-ARMCHAIR") is not None
     product = uow.products.get("CRUNCHY-ARMCHAIR")
@@ -87,43 +87,43 @@ def test_allocate_returns_allocation():
     event = events.BatchCreated(
         reference="batch1", sku="COMPLICATED-LAMP", qty=100
     )
-    handlers.add_batch(event, uow)
+    messagebus.handle(event, uow)
 
     event = events.AllocationRequired(
         orderid="order1", sku="COMPLICATED-LAMP", qty=10
     )
-    result = handlers.allocate(event=event, uow=uow)
+    [batchref] = messagebus.handle(event, uow)
 
-    assert result == "batch1"
+    assert batchref == "batch1"
     assert uow.committed
 
 
 def test_allocate_errors_for_invalid_sku():
     uow = FakeUnitOfWork()
     event = events.BatchCreated(reference="batch1", sku="AREALSKU", qty=100)
-    handlers.add_batch(event, uow)
+    messagebus.handle(event, uow)
 
     with pytest.raises(
         handlers.InvalidSku, match="Invalid sku NON-EXISTENTSKU"
     ):
         event = events.AllocationRequired(
             orderid="order1", sku="NON-EXISTENTSKU", qty=10
         )
-        handlers.allocate(event=event, uow=uow)
+        messagebus.handle(event, uow)
 
 
 def test_deallocate():
     uow = FakeUnitOfWork()
     event = events.BatchCreated(
         reference="batch1", sku="COMPLICATED-LAMP", qty=100
     )
-    handlers.add_batch(event, uow)
+    messagebus.handle(event, uow)
 
     event = events.AllocationRequired(
         orderid="order1", sku="COMPLICATED-LAMP", qty=10
     )
-    result = handlers.allocate(event=event, uow=uow)
-    assert result == "batch1"
+    [batchref] = messagebus.handle(event, uow)
+    assert batchref == "batch1"
     product = uow.products.get("COMPLICATED-LAMP")
     batch = product.batches[0]
     assert batch.reference == "batch1"
@@ -132,7 +132,7 @@ def test_deallocate():
     event = events.DeallocationRequired(
         orderid="order1", sku="COMPLICATED-LAMP", qty=10
     )
-    handlers.deallocate(event, uow)
+    messagebus.handle(event, uow)
 
     assert batch.allocated_quaitity == 0
     assert uow.committed