feat: add SetTitle to ClassifiedAd with domain events, extract EnsureValidState

domain/marketplace/classified_ad.py

@@ -1,10 +1,17 @@
+from __future__ import annotations
+
 from dataclasses import dataclass, field
 from decimal import Decimal
 
+from domain.framework.entity import Entity
 from domain.marketplace.classified_ad_id import ClassifiedAdId
 from domain.marketplace.classified_ad_state import ClassifiedAdState
 from domain.marketplace.classified_ad_text import ClassifiedAdText
 from domain.marketplace.classified_ad_title import ClassifiedAdTitle
+from domain.marketplace.domain_event import (
+    ClassifiedAdTitleChanged,
+    DomainEvent,
+)
 from domain.marketplace.invalid_entity_state_exception import (
     InvalidEntityStateException,
 )
@@ -13,15 +20,16 @@ from domain.marketplace.user_id import UserId
 
 
 @dataclass(frozen=True)
-class ClassifiedAd:
+class ClassifiedAd(Entity):
     id: ClassifiedAdId
     _ownerId: UserId
     title: ClassifiedAdTitle
     text: ClassifiedAdText
     price: Price = field(default_factory=lambda: Price(amount=Decimal("0.00")))
     state: ClassifiedAdState | None = None
+    _events: tuple[DomainEvent, ...] = ()
 
-    def request_to_publish(self):
+    def _ensure_valid_state(self):
         errors = []
         if not self.title.title:
             errors.append("title")
@@ -35,6 +43,9 @@ class ClassifiedAd:
                 f"Cannot publish classified ad with missing or invalid: {', '.join(errors)}"
             )
 
+    def request_to_publish(self):
+        self._ensure_valid_state()
+
         return ClassifiedAd(
             id=self.id,
             _ownerId=self._ownerId,
@@ -42,4 +53,20 @@ class ClassifiedAd:
             text=self.text,
             price=self.price,
             state=ClassifiedAdState.PendingReview,
+            _events=self._events,
+        )
+
+    def set_title(self, title: ClassifiedAdTitle) -> ClassifiedAd:
+        updated = ClassifiedAd(
+            id=self.id,
+            _ownerId=self._ownerId,
+            title=title,
+            text=self.text,
+            price=self.price,
+            state=self.state,
+            _events=self._events,
+        )
+        updated._ensure_valid_state()
+        return updated.raise_event(
+            ClassifiedAdTitleChanged(id=self.id.value, title=title.title)
         )

tests/test_classified_ad.py

@@ -3,11 +3,16 @@ from uuid import uuid4
 
 import pytest
 
+from domain.framework.entity import Entity
 from domain.marketplace.classified_ad import ClassifiedAd
 from domain.marketplace.classified_ad_id import ClassifiedAdId
 from domain.marketplace.classified_ad_state import ClassifiedAdState
 from domain.marketplace.classified_ad_text import ClassifiedAdText
 from domain.marketplace.classified_ad_title import ClassifiedAdTitle
+from domain.marketplace.domain_event import (
+    ClassifiedAdSentForReview,
+    ClassifiedAdTitleChanged,
+)
 from domain.marketplace.invalid_entity_state_exception import (
     InvalidEntityStateException,
 )
@@ -219,3 +224,102 @@ def test_request_to_publish_does_not_mutate_original():
     ad.request_to_publish()
 
     assert ad.state is None
+
+
+def test_classified_ad_is_instance_of_entity():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Title"),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+
+    assert isinstance(ad, Entity)
+
+
+def test_classified_ad_can_use_entity_raise_event():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Title"),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+    event = ClassifiedAdSentForReview(id=ad.id.value)
+
+    updated_ad = ad.raise_event(event)
+
+    assert updated_ad.get_changes() == (event,)
+    assert ad.get_changes() == ()
+
+
+def test_set_title_updates_title():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Old Title"),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+    new_title = ClassifiedAdTitle(title="New Title")
+
+    updated = ad.set_title(new_title)
+
+    assert updated.title == new_title
+    assert ad.title == ClassifiedAdTitle(title="Old Title")
+
+
+def test_set_title_preserves_other_fields():
+    ad_id = ClassifiedAdId(value=uuid4())
+    owner_id = UserId(value=uuid4())
+    text = ClassifiedAdText(text="Text")
+    price = Price(amount=Decimal("10.00"))
+    ad = ClassifiedAd(
+        id=ad_id,
+        _ownerId=owner_id,
+        title=ClassifiedAdTitle(title="Old Title"),
+        text=text,
+        price=price,
+    )
+
+    updated = ad.set_title(ClassifiedAdTitle(title="New Title"))
+
+    assert updated.id == ad_id
+    assert updated._ownerId == owner_id
+    assert updated.text == text
+    assert updated.price == price
+
+
+def test_set_title_fails_when_new_title_empty():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Title"),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+
+    with pytest.raises(InvalidEntityStateException) as exc_info:
+        ad.set_title(ClassifiedAdTitle(title=""))
+
+    assert "title" in str(exc_info.value)
+
+
+def test_set_title_raises_classified_ad_title_changed_event():
+    ad = ClassifiedAd(
+        id=ClassifiedAdId(value=uuid4()),
+        _ownerId=UserId(value=uuid4()),
+        title=ClassifiedAdTitle(title="Old Title"),
+        text=ClassifiedAdText(text="Text"),
+        price=Price(amount=Decimal("10.00")),
+    )
+
+    updated = ad.set_title(ClassifiedAdTitle(title="New Title"))
+
+    changes = updated.get_changes()
+    assert len(changes) == 1
+    event = changes[0]
+    assert isinstance(event, ClassifiedAdTitleChanged)
+    assert event.id == ad.id.value
+    assert event.title == "New Title"