Application (#18)

implementation of the Application class, refactor of event handling

Author: pgorecki

.idea/vcs.xml

@@ -3,13 +3,13 @@
 from api.models import ListingIndexModel, ListingReadModel, ListingWriteModel
 from api.shared import dependency
 from config.container import Container, inject
-from modules.catalog import CatalogModule
 from modules.catalog.application.command import (
     CreateListingDraftCommand,
     DeleteListingDraftCommand,
 )
 from modules.catalog.application.query.get_all_listings import GetAllListings
 from modules.catalog.application.query.get_listing_details import GetListingDetails
+from seedwork.application import Application
 from seedwork.domain.value_objects import Money
 from seedwork.infrastructure.request_context import request_context
 
@@ -19,30 +19,28 @@
 @router.get("/catalog", tags=["catalog"], response_model=ListingIndexModel)
 @inject
 async def get_all_listings(
-    module: CatalogModule = dependency(Container.catalog_module),
+    app: Application = dependency(Container.application),
 ):
     """
     Shows all published listings in the catalog
     """
     query = GetAllListings()
-    with module.unit_of_work():
-        query_result = module.execute_query(query)
-        return dict(data=query_result.payload)
+    query_result = app.execute_query(query)
+    return dict(data=query_result.payload)
 
 
 @router.get("/catalog/{listing_id}", tags=["catalog"], response_model=ListingReadModel)
 @inject
 async def get_listing_details(
     listing_id,
-    module: CatalogModule = dependency(Container.catalog_module),
+    app: Application = dependency(Container.application),
 ):
     """
     Shows listing details
     """
     query = GetListingDetails(listing_id=listing_id)
-    with module.unit_of_work():
-        query_result = module.execute_query(query)
-        return query_result.payload
+    query_result = app.execute_query(query)
+    return dict(data=query_result.payload)
 
 
 @router.post(
@@ -51,7 +49,7 @@ async def get_listing_details(
 @inject
 async def create_listing(
     request_body: ListingWriteModel,
-    module: CatalogModule = dependency(Container.catalog_module),
+    app: Application = dependency(Container.application),
 ):
     """
     Creates a new listing.
@@ -62,12 +60,11 @@ async def create_listing(
         ask_price=Money(request_body.ask_price_amount, request_body.ask_price_currency),
         seller_id=request_context.current_user.id,
     )
-    with module.unit_of_work():
-        command_result = module.execute_command(command)
+    command_result = app.execute_command(command)
 
-        query = GetListingDetails(listing_id=command_result.result)
-        query_result = module.execute_query(query)
-        return query_result.payload
+    query = GetListingDetails(listing_id=command_result.payload)
+    query_result = app.execute_query(query)
+    return dict(data=query_result.payload)
 
 
 @router.delete(
@@ -76,13 +73,12 @@ async def create_listing(
 @inject
 async def delete_listing(
     listing_id,
-    module: CatalogModule = dependency(Container.catalog_module),
+    app: Application = dependency(Container.application),
 ):
     """
     Delete listing
     """
     command = DeleteListingDraftCommand(
         listing_id=listing_id,
     )
-    with module.unit_of_work():
-        module.execute_command(command)
+    app.execute_command(command)

src/api/routers/catalog.py

@@ -14,16 +14,15 @@ def test_empty_catalog_list(api_client):
 @pytest.mark.integration
 def test_catalog_list_with_one_item(api, api_client):
     # arrange
-    catalog_module = api.container.catalog_module()
-    with catalog_module.unit_of_work():
-        command_result = catalog_module.execute_command(
-            CreateListingDraftCommand(
-                title="Foo",
-                description="Bar",
-                ask_price=Money(10),
-                seller_id=UUID("00000000000000000000000000000002"),
-            )
+    app = api.container.application()
+    command_result = app.execute_command(
+        CreateListingDraftCommand(
+            title="Foo",
+            description="Bar",
+            ask_price=Money(10),
+            seller_id=UUID("00000000000000000000000000000002"),
         )
+    )
 
     # act
     response = api_client.get("/catalog")
@@ -48,24 +47,23 @@ def test_catalog_list_with_one_item(api, api_client):
 @pytest.mark.integration
 def test_catalog_list_with_two_items(api, api_client):
     # arrange
-    catalog_module = api.container.catalog_module()
-    with catalog_module.unit_of_work():
-        catalog_module.execute_command(
-            CreateListingDraftCommand(
-                title="Foo #1",
-                description="Bar",
-                ask_price=Money(10),
-                seller_id=UUID("00000000000000000000000000000002"),
-            )
+    app = api.container.application()
+    app.execute_command(
+        CreateListingDraftCommand(
+            title="Foo #1",
+            description="Bar",
+            ask_price=Money(10),
+            seller_id=UUID("00000000000000000000000000000002"),
         )
-        catalog_module.execute_command(
-            CreateListingDraftCommand(
-                title="Foo #2",
-                description="Bar",
-                ask_price=Money(10),
-                seller_id=UUID("00000000000000000000000000000002"),
-            )
+    )
+    app.execute_command(
+        CreateListingDraftCommand(
+            title="Foo #2",
+            description="Bar",
+            ask_price=Money(10),
+            seller_id=UUID("00000000000000000000000000000002"),
         )
+    )
 
     # act
     response = api_client.get("/catalog")
@@ -89,18 +87,17 @@ def test_catalog_create_draft_fails_due_to_incomplete_data(api, api_client):
 
 @pytest.mark.integration
 def test_catalog_delete_draft(api, api_client):
-    catalog_module = api.container.catalog_module()
-    with catalog_module.unit_of_work():
-        result = catalog_module.execute_command(
-            CreateListingDraftCommand(
-                title="Foo to be deleted",
-                description="Bar",
-                ask_price=Money(10),
-                seller_id=UUID("00000000000000000000000000000002"),
-            )
+    app = api.container.application()
+    command_result = app.execute_command(
+        CreateListingDraftCommand(
+            title="Foo to be deleted",
+            description="Bar",
+            ask_price=Money(10),
+            seller_id=UUID("00000000000000000000000000000002"),
         )
+    )
 
-    response = api_client.delete(f"/catalog/{result.entity_id}")
+    response = api_client.delete(f"/catalog/{command_result.entity_id}")
 
     assert response.status_code == 204
 

src/api/tests/test_catalog.py

@@ -1,3 +1,8 @@
+import uuid
+from contextlib import contextmanager
+
+from sqlalchemy.orm import Session
+
 from config.container import Container
 from modules.catalog.application.command.create_listing_draft import (
     CreateListingDraftCommand,
@@ -6,13 +11,28 @@
 from modules.catalog.infrastructure.listing_repository import Base
 from seedwork.infrastructure.logging import LoggerFactory, logger
 
+
+@contextmanager
+def unit_of_work(module):
+    from seedwork.infrastructure.request_context import request_context
+
+    with Session(engine) as db_session:
+        correlation_id = uuid.uuid4()
+        request_context.correlation_id.set(correlation_id)
+        with module.unit_of_work(
+            correlation_id=correlation_id, db_session=db_session
+        ) as uow:
+            yield uow
+        db_session.commit()
+        request_context.correlation_id.set(None)
+
+
 # a sample command line script to print all listings
 # run with "cd src && python -m cli"
 
 # configure logger prior to first usage
 LoggerFactory.configure(logger_name="cli")
 
-
 container = Container()
 container.config.from_dict(
     dict(
@@ -25,22 +45,24 @@
 engine = container.engine()
 Base.metadata.create_all(engine)
 
-catalog_module = container.catalog_module()
+app = container.application()
+
 
-with catalog_module.unit_of_work() as uow:
+with unit_of_work(app.catalog) as uow:
     logger.info(f"executing unit of work")
     count = uow.listing_repository.count()
     logger.info(f"{count} listing in the repository")
 
-with catalog_module.unit_of_work():
-    logger.info(f"adding new draft")
-    catalog_module.execute_command(
-        CreateListingDraftCommand(
-            title="First listing", description=".", ask_price=Money(100), seller_id=None
-        )
+
+logger.info(f"adding new draft")
+command_result = app.execute_command(
+    CreateListingDraftCommand(
+        title="First listing", description=".", ask_price=Money(100), seller_id=None
     )
+)
+print(command_result)
 
-with catalog_module.unit_of_work() as uow:
+with unit_of_work(app.catalog) as uow:
     logger.info(f"executing unit of work")
     count = uow.listing_repository.count()
     logger.info(f"{count} listing in the repository")

src/cli/__main__.py

@@ -4,7 +4,8 @@
 
 from modules.catalog import CatalogModule
 from modules.iam import IamModule
-from seedwork.application.event_dispatcher import InMemoryEventDispatcher
+from seedwork.application import Application
+from seedwork.application.inbox_outbox import InMemoryOutbox
 
 
 def _default(val):
@@ -47,6 +48,18 @@ def create_engine_once(config):
     return engine
 
 
+def create_app(name, version, config, engine, catalog_module, outbox) -> Application:
+    app = Application(
+        name=name,
+        version=version,
+        config=config,
+        engine=engine,
+        outbox=outbox,
+    )
+    app.add_module("catalog", catalog_module)
+    return app
+
+
 class Container(containers.DeclarativeContainer):
     """Dependency Injection Container
 
@@ -57,16 +70,22 @@ class Container(containers.DeclarativeContainer):
 
     config = providers.Configuration()
     engine = providers.Singleton(create_engine_once, config)
-    domain_event_dispatcher = InMemoryEventDispatcher()
+    outbox = providers.Factory(InMemoryOutbox)
 
     catalog_module = providers.Factory(
         CatalogModule,
-        engine=engine,
-        domain_event_dispatcher=domain_event_dispatcher,
     )
 
     iam_module = providers.Factory(
         IamModule,
+    )
+
+    application = providers.Factory(
+        create_app,
+        name="Auctions API",
+        version="0.1.0",
+        config=config,
         engine=engine,
-        domain_event_dispatcher=domain_event_dispatcher,
+        catalog_module=catalog_module,
+        outbox=outbox,
     )

src/config/container.py

@@ -1 +1,27 @@
-Item catalog module
+# Listing catalog module
+
+This part is a seller portal. It allows sellers to create and manage their listings.
+
+# Business rules
+
+# User stories:
+
+- [x] As a seller, I want to create a listing draft for a product I want to sell.
+
+- [x] As a seller, I want to update a listing draft.
+
+- [ ] As a seller, I want to delete a listing draft.
+
+- [ ] As a seller, I want to publish a listing draft immediately.
+
+- [ ] As a seller, I want to schedule a listing draft for publishing.
+
+- [ ] As a seller, I want to end a listing immediately.
+
+- [ ] As a seller, I want to view all my listings (published, unpublished, ended).
+
+- [ ] As a seller, I want to view details of a listing.
+
+- [ ] As a system, I want to notify a seller when a listing is published.
+
+- [ ] As a system, I want to notify a seller when a listing is ended.

src/modules/catalog/README.md

@@ -1,7 +1,7 @@
 from modules.catalog.application.command import (
     CreateListingDraftCommand,
     DeleteListingDraftCommand,
-    PublishListingCommand,
+    PublishListingDraftCommand,
     UpdateListingDraftCommand,
 )
 from modules.catalog.application.query import (
@@ -21,7 +21,7 @@ class CatalogModule(BusinessModule):
         CreateListingDraftCommand,
         UpdateListingDraftCommand,
         DeleteListingDraftCommand,
-        PublishListingCommand,
+        PublishListingDraftCommand,
     )
     supported_queries = (GetAllListings, GetListingDetails, GetListingsOfSeller)
 

src/modules/catalog/__init__.py

@@ -1,4 +1,4 @@
 from .create_listing_draft import CreateListingDraftCommand
 from .delete_listing_draft import DeleteListingDraftCommand
-from .publish_listing import PublishListingCommand
+from .publish_listing_draft import PublishListingDraftCommand
 from .update_listing_draft import UpdateListingDraftCommand

src/modules/catalog/application/command/__init__.py

@@ -3,6 +3,7 @@
 from modules.catalog.domain.entities import Listing
 from modules.catalog.domain.events import ListingDraftCreatedEvent
 from modules.catalog.domain.repositories import ListingRepository
+from modules.catalog.domain.value_objects import ListingStatus
 from seedwork.application.command_handlers import CommandResult
 from seedwork.application.commands import Command
 from seedwork.application.decorators import command_handler