return events from command handlers, fix tests

Author: pgorecki

src/modules/bidding/application/command/place_bid.py

@@ -1,26 +1,25 @@
 from decimal import Decimal
 from seedwork.application.command_handlers import CommandResult
 from seedwork.application.decorators import command_handler
-from src.modules.bidding.domain.entities import Bidding
+from src.modules.bidding.domain.entities import Listing
+from src.modules.bidding.domain.value_objects import Bid, Bidder, Money
 from src.modules.bidding.domain.repositories import ListingRepository
 
 
 class PlaceBidCommand:
-    buyer_id: str
+    listing_id: str
+    bidder_id: str
     amount: Decimal
     currency: str = "USD"
 
 
 @command_handler
 def place_bid(command: PlaceBidCommand, repository: ListingRepository) -> CommandResult:
-    listing = repository.get_by_id(listing_id=command.listing_id)
-    if listing is None:
-        return CommandResult.failed("Listing does not exist")
-
-    buyer = Buyer(id=command.buyer_id)
-    money = Money(amount=command.amount)
-    buyer.place_bid(listing, money)
+    bidder = Bidder(id=command.bidder_id)
+    bid = Bid(bidder=bidder, price=Money(command.amount))
 
+    listing: Listing = repository.get_by_id(id=command.listing_id)
+    events = listing.place_bid(bid)
     repository.update(listing)
 
-    return CommandResult.ok()
+    return CommandResult.ok(events=events)

src/modules/bidding/application/command/retract_bid.py

@@ -1,28 +1,26 @@
 from decimal import Decimal
 from seedwork.application.command_handlers import CommandResult
 from seedwork.application.decorators import command_handler
-from src.modules.bidding.domain.entities import Bidding
+from src.modules.bidding.domain.entities import Listing
+from src.modules.bidding.domain.value_objects import Bidder
 from src.modules.bidding.domain.repositories import ListingRepository
 
 
 class RetractBidCommand:
-    buyer_id: str
+    listing_id: str
+    bidder_id: str
     amount: Decimal
     currency: str = "USD"
 
 
 @command_handler
 def retract_bid(
-    command: PlaceBidCommand, repository: ListingRepository
+    command: RetractBidCommand, repository: ListingRepository
 ) -> CommandResult:
-    listing = repository.get_by_id(listing_id=command.listing_id)
-    if listing is None:
-        return CommandResult.failed("Listing does not exist")
+    bidder = Bidder(id=command.bidder_id)
 
-    buyer = Buyer(id=command.buyer_id)
-    money = Money(amount=command.amount)
-    bid = Bid(buyer=buyer, money=money)
-    listing.place_bid(bid)
+    listing: Listing = repository.get_by_id(id=command.listing_id)
+    events = listing.retract_bid_of(bidder)
     repository.update(listing)
 
-    return CommandResult.ok()
+    return CommandResult.ok(events=events)

src/modules/bidding/application/query/get_pastdue_listings.py

@@ -1,7 +1,8 @@
 from datetime import datetime
-from modules.bidding.domain.repositories import ListingRepository
 from seedwork.application.queries import Query, Field
+from seedwork.application.query_handlers import QueryResult
 from seedwork.application.decorators import query_handler
+from modules.bidding.domain.repositories import ListingRepository
 
 
 class GetPastdueListingsQuery(Query):
@@ -11,6 +12,6 @@ class GetPastdueListingsQuery(Query):
 @query_handler
 def get_past_due_listings(
     query: GetPastdueListingsQuery, listing_repository: ListingRepository
-):
+) -> QueryResult:
     # TODO: not yet implemented
-    return []
+    return QueryResult([])

src/modules/bidding/domain/test_listing.py

@@ -8,7 +8,7 @@
 
 
 def test_listing_initial_price():
-    seller = Seller(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,
@@ -20,8 +20,8 @@ def test_listing_initial_price():
 
 def test_place_one_bid():
     now = datetime.utcnow()
-    seller = Seller(uuid=UUID.v4())
-    bidder = Bidder(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
+    bidder = Bidder(id=UUID.v4())
     bid = Bid(price=Money(20), bidder=bidder, placed_at=now)
     listing = Listing(
         id=Listing.next_id(),
@@ -35,9 +35,9 @@ def test_place_one_bid():
 
 def test_place_two_bids():
     now = datetime.utcnow()
-    seller = Seller(uuid=UUID.v4())
-    bidder1 = Bidder(uuid=UUID.v4())
-    bidder2 = Bidder(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
+    bidder1 = Bidder(id=UUID.v4())
+    bidder2 = Bidder(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,
@@ -51,8 +51,8 @@ def test_place_two_bids():
 
 def test_place_two_bids_by_same_bidder():
     now = datetime.utcnow()
-    seller = Seller(uuid=UUID.v4())
-    bidder = Bidder(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
+    bidder = Bidder(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,
@@ -67,8 +67,8 @@ def test_place_two_bids_by_same_bidder():
 
 
 def test_cannot_place_bid_if_listing_ended():
-    seller = Seller(uuid=UUID.v4())
-    bidder = Bidder(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
+    bidder = Bidder(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,
@@ -88,8 +88,8 @@ def test_cannot_place_bid_if_listing_ended():
 
 
 def test_retract_bid():
-    seller = Seller(uuid=UUID.v4())
-    bidder = Bidder(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
+    bidder = Bidder(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,
@@ -108,7 +108,7 @@ def test_retract_bid():
 
 def test_cancel_listing():
     now = datetime.utcnow()
-    seller = Seller(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,
@@ -123,8 +123,8 @@ def test_cancel_listing():
 
 def test_can_cancel_listing_with_bids():
     now = datetime.utcnow()
-    seller = Seller(uuid=UUID.v4())
-    bidder = Bidder(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
+    bidder = Bidder(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,
@@ -145,8 +145,8 @@ def test_can_cancel_listing_with_bids():
 
 def test_cannot_cancel_listing_with_bids():
     now = datetime.utcnow()
-    seller = Seller(uuid=UUID.v4())
-    bidder = Bidder(uuid=UUID.v4())
+    seller = Seller(id=UUID.v4())
+    bidder = Bidder(id=UUID.v4())
     listing = Listing(
         id=Listing.next_id(),
         seller=seller,

src/modules/bidding/domain/value_objects.py

@@ -5,12 +5,12 @@
 
 @dataclass
 class Bidder(ValueObject):
-    uuid: UUID
+    id: UUID
 
 
 @dataclass
 class Seller(ValueObject):
-    uuid: UUID
+    id: UUID
 
 
 @dataclass

src/modules/catalog/domain/entities.py

@@ -1,3 +1,4 @@
+from dataclasses import dataclass
 from datetime import date
 from typing import Any
 from seedwork.domain.entities import Entity

src/modules/catalog/domain/rules.py

@@ -20,7 +20,7 @@ class ListingPriceMustBeGreaterThanZero(BusinessRule):
     price: Money
 
     def is_broken(self) -> bool:
-        return self.price <= 0
+        return self.price.amount <= 0
 
 
 class SellerMustBeEligibleForAddingNextListing(BusinessRule):

src/seedwork/application/command_handlers.py

@@ -1,9 +1,12 @@
 import sys
+from typing import Any, List
+from seedwork.domain.type_hints import DomainEvent
 
 
 class CommandResult:
-    def __init__(self, result) -> None:
+    def __init__(self, result: Any, events: List[DomainEvent]) -> None:
         self.__result = result
+        self.__events = events
         self.__errors = []
 
     # commands
@@ -13,33 +16,45 @@ def add_error(self, message, exception=None, exception_info=None):
 
     # queries
     @property
-    def result(self):
+    def result(self) -> Any:
         """Shortcut to get_result()"""
         return self.get_result()
 
-    def get_result(self):
+    def get_result(self) -> Any:
         """Gets result"""
         assert (
             not self.has_errors()
         ), f"Cannot access result. QueryResult has errors.\n  Errors: {self.__errors}"
         return self.__result
 
+    @property
+    def events(self) -> List[DomainEvent]:
+        """Shortcut to get_events()"""
+        return self.get_events()
+
+    def get_events(self) -> List[DomainEvent]:
+        """Gets result"""
+        assert (
+            not self.has_errors()
+        ), f"Cannot access events. QueryResult has errors.\n  Errors: {self.__errors}"
+        return self.__events
+
     def get_errors(self):
         return self.__errors
 
     def has_errors(self):
         return len(self.__errors) > 0
 
-    def is_ok(self):
+    def is_ok(self) -> bool:
         return not self.has_errors()
 
     @classmethod
-    def ok(cls, result):
+    def ok(cls, result=None, events=[]) -> "CommandResult":
         """Creates a successful result"""
-        return cls(result=result)
+        return cls(result=result, events=events)
 
     @classmethod
-    def failed(cls, message="Failure", exception=None):
+    def failed(cls, message="Failure", exception=None) -> "CommandResult":
         """Creates a failed result"""
         result = cls(result=None)
         exception_info = sys.exc_info()

src/seedwork/application/queries.py

@@ -1,4 +1,4 @@
-from pydantic import BaseModel
+from pydantic import BaseModel, Field
 
 
 class Query(BaseModel):

src/seedwork/infrastructure/test_repository.py

@@ -1,15 +1,16 @@
+from dataclasses import dataclass
 from seedwork.infrastructure.repository import InMemoryRepository
 from seedwork.domain.entities import Entity
 
-
+@dataclass
 class Person(Entity):
     first_name: str
     last_name: str
 
 
 def test_InMemoryRepository_persist_one():
     # arrange
-    person = Person(first_name="John", last_name="Doe")
+    person = Person(id=Person.next_id(), first_name="John", last_name="Doe")
     repository = InMemoryRepository()
 
     # act
@@ -21,8 +22,8 @@ def test_InMemoryRepository_persist_one():
 
 def test_InMemoryRepository_persist_two():
     # arrange
-    person1 = Person(first_name="John", last_name="Doe")
-    person2 = Person(first_name="Mary", last_name="Doe")
+    person1 = Person(id=Person.next_id(), first_name="John", last_name="Doe")
+    person2 = Person(id=Person.next_id(), first_name="Mary", last_name="Doe")
     repository = InMemoryRepository()
 
     # act