Add Checkout related events along with tests

src/lending/book.py

@@ -3,8 +3,8 @@
 from protean import handle
 from protean.fields import String
 
-from lending.patron import HoldPlaced
 from lending.domain import lending
+from lending.patron import HoldPlaced
 
 
 class BookStatus(Enum):

src/lending/checkout_service.py

@@ -1,10 +1,10 @@
 from protean import invariant
-from protean.exceptions import ValidationError
+from protean.exceptions import ObjectNotFoundError, ValidationError
 from protean.fields import Identifier
 
-from lending.patron import Checkout, HoldStatus, Patron, PatronType
 from lending.book import Book, BookType
 from lending.domain import lending
+from lending.patron import BookCheckedOut, Checkout, Patron, PatronType
 
 
 @lending.domain_service(part_of=[Patron, Book])
@@ -29,19 +29,30 @@ def regular_patron_cannot_place_hold_on_restricted_book(self):
             )
 
     def __call__(self):
-        self.patron.add_checkouts(
-            Checkout(
-                book_id=self.book.id,
-                branch_id=self.branch_id,
-            )
+        checkout = Checkout(
+            book_id=self.book.id,
+            branch_id=self.branch_id,
         )
+        self.patron.add_checkouts(checkout)
 
         # Find and update hold corresponding to book if it exists
+        hold = None
         try:
-            hold = next(h for h in self.patron.holds if h.book_id == self.book.id)
-        except StopIteration:
+            hold = self.patron.get_one_from_holds(book_id=self.book.id)
+        except ObjectNotFoundError:
             hold = None
 
         if hold:
-            hold.status = HoldStatus.CHECKED_OUT.value
-            self.patron.add_holds(hold)
+            hold.checkout()
+
+        # Raise Event
+        checkout.raise_(
+            BookCheckedOut(
+                patron_id=self.patron.id,
+                patron_type=self.patron.patron_type,
+                book_id=self.book.id,
+                branch_id=self.branch_id,
+                checkout_date=checkout.checkout_date,
+                due_date=checkout.due_date,
+            )
+        )

src/lending/holding_service.py

@@ -5,8 +5,8 @@
 from protean.fields import Identifier
 
 from lending.book import Book, BookStatus, BookType
-from lending.patron import Hold, HoldPlaced, HoldStatus, HoldType, Patron, PatronType
 from lending.domain import lending
+from lending.patron import Hold, HoldPlaced, HoldStatus, HoldType, Patron, PatronType
 
 
 @lending.domain_service(part_of=[Patron, Book])

src/lending/patron.py

@@ -81,6 +81,9 @@ class Hold:
     request_date = DateTime(required=True)
     expiry_date = Date(required=True)
 
+    def checkout(self):
+        self.status = HoldStatus.CHECKED_OUT.value
+
     def expire(self):
         self.status = HoldStatus.EXPIRED.value
 
@@ -125,6 +128,43 @@ class CheckoutStatus(Enum):
     OVERDUE = "OVERDUE"
 
 
+@lending.event(part_of="Patron")
+class BookCheckedOut:
+    """Event raised when a patron checks out a book"""
+
+    patron_id = Identifier(required=True)
+    patron_type = String(required=True)
+    book_id = Identifier(required=True)
+    branch_id = Identifier(required=True)
+    checkout_date = DateTime(required=True)
+    due_date = Date(required=True)
+
+
+@lending.event(part_of="Patron")
+class BookReturned:
+    """Event raised when a patron returns a book"""
+
+    patron_id = Identifier(required=True)
+    patron_type = String(required=True)
+    book_id = Identifier(required=True)
+    branch_id = Identifier(required=True)
+    checkout_date = DateTime(required=True)
+    due_date = Date(required=True)
+    return_date = DateTime(required=True)
+
+
+@lending.event(part_of="Patron")
+class BookOverdue:
+    """Event raised when a book is marked overdue"""
+
+    patron_id = Identifier(required=True)
+    patron_type = String(required=True)
+    book_id = Identifier(required=True)
+    branch_id = Identifier(required=True)
+    checkout_date = DateTime(required=True)
+    due_date = Date(required=True)
+
+
 @lending.entity(part_of="Patron")
 class Checkout:
     """The action of a patron borrowing a book from the library
@@ -145,9 +185,32 @@ def return_(self):
         self.status = CheckoutStatus.RETURNED.value
         self.return_date = datetime.now()
 
+        self.raise_(
+            BookReturned(
+                patron_id=self._owner.id,
+                patron_type=self._owner.patron_type,
+                book_id=self.book_id,
+                branch_id=self.branch_id,
+                checkout_date=self.checkout_date,
+                due_date=self.due_date,
+                return_date=self.return_date,
+            )
+        )
+
     def overdue(self):
         self.status = CheckoutStatus.OVERDUE.value
 
+        self.raise_(
+            BookOverdue(
+                patron_id=self._owner.id,
+                patron_type=self._owner.patron_type,
+                book_id=self.book_id,
+                branch_id=self.branch_id,
+                checkout_date=self.checkout_date,
+                due_date=self.due_date,
+            )
+        )
+
 
 @lending.aggregate
 class Patron:

tests/lending/bdd/checkouts/features/check_out_a_book.feature

@@ -7,6 +7,7 @@ Feature: Check Out a Book
     When the patron checks out the book
     Then the checkout is successfully completed
     And the checkout has a validity of CHECKOUT_PERIOD
+    And the hold is marked as checked out
 
   Scenario: Patron checks out an available circulating book
     Given a circulating book is available

tests/lending/bdd/checkouts/features/overdue_checkouts.feature

@@ -3,4 +3,4 @@ Feature: Process Overdue Checkouts
   Scenario: System processes and updates the status of overdue checkouts
     Given the system has overdue checkouts
     When the system processes the overdue checkouts
-    Then the checkout statuses are updated to overdue
+    Then the checkouts are marked overdue

tests/lending/bdd/checkouts/features/return_a_book.feature

@@ -3,11 +3,11 @@ Feature: Return a Book
   Scenario: Patron returns a book on or before the due date
     Given a patron has checked out a book
     When the patron returns the book
-    Then the return is successfully processed
+    Then the book is successfully returned
 
   Scenario: Patron returns a book after the due date
     Given a patron has checked out a book
     And the book is overdue
     When the patron returns the book
-    Then the return is successfully processed
+    Then the book is successfully returned
     And the overdue status is cleared

tests/lending/bdd/checkouts/step_defs/checkout_steps.py

@@ -130,6 +130,10 @@ def confirm_checkout_book():
     assert len(g.current_user.checkouts) == 1
     assert g.current_user.checkouts[0].book_id == g.current_book.id
 
+    assert "BookCheckedOut" in [
+        event.__class__.__name__ for event in g.current_user._events
+    ]
+
 
 @then(cfparse("the checkout has a validity of {validity_days_config}"))
 def confirm_checkout_expiry(validity_days_config):
@@ -150,13 +154,29 @@ def confirm_returned_status():
     assert g.current_user.checkouts[0].status == "RETURNED"
 
 
-@then("the return is successfully processed")
+@then("the book is successfully returned")
 def confirm_successful_return():
     assert hasattr(g, "current_exception") is False
 
+    assert "BookReturned" in [
+        event.__class__.__name__ for event in g.current_user._events
+    ]
+
 
-@then("the checkout statuses are updated to overdue")
+@then("the checkouts are marked overdue")
 def confirm_overdue_marking():
     assert g.current_patrons[0].checkouts[0].status == "OVERDUE"
     assert g.current_patrons[1].checkouts[0].status == "OVERDUE"
     assert hasattr(g, "current_exception") is False
+
+    assert "BookOverdue" in [
+        event.__class__.__name__ for event in g.current_patrons[0]._events
+    ]
+    assert "BookOverdue" in [
+        event.__class__.__name__ for event in g.current_patrons[1]._events
+    ]
+
+
+@then("the hold is marked as checked out")
+def confirm_hold_checked_out():
+    assert g.current_user.holds[0].status == "CHECKED_OUT"

tests/lending/bdd/daily_sheet/features/overdue_checkouts_sheet.feature

@@ -9,4 +9,4 @@ Feature: Generate Daily Sheets for Overdue Checkouts
   Scenario: System processes and updates the status of overdue checkouts
     Given the system has generated a daily sheet for overdue checkouts
     When the system processes the overdue checkouts
-    Then the checkout statuses are updated to overdue
+    Then the checkouts are marked overdue