Remove domain-level event raise_ functionality

Events, at this point, should always be connected to aggregates,
and raised from within them as part of business logic. Directly
adding events at the domain level was helper functionality, but
with the addition of metadata and headers at the event level,
events have a lot more contextuality. They cannot be raised or
appended to event store directly.

We will need to revisit this functionality if we need Domain
Events (or some variation thereof) that are not connected to
aggregates.

src/protean/core/event.py

@@ -32,7 +32,7 @@ def __new__(cls, *args, **kwargs):
         return super().__new__(cls)
 
     # Track Metadata
-    _metadata = ValueObject(Metadata, default=lambda: Metadata())
+    _metadata = ValueObject(Metadata, default=lambda: Metadata())  # pragma: no cover
 
     def __init_subclass__(subclass) -> None:
         super().__init_subclass__()

src/protean/core/event_sourced_repository.py

@@ -1,6 +1,6 @@
 import logging
 
-from protean import BaseEventSourcedAggregate
+from protean import BaseEventSourcedAggregate, UnitOfWork
 from protean.container import Element, OptionsMixin
 from protean.exceptions import (
     IncorrectUsageError,
@@ -31,7 +31,21 @@ def __init__(self, domain) -> None:
         self._domain = domain
 
     def add(self, aggregate: BaseEventSourcedAggregate) -> None:
-        current_uow._add_to_identity_map(aggregate)
+        # `add` is typically invoked in handler methods in Command Handlers and Event Handlers, which are
+        #   enclosed in a UoW automatically. Therefore, if there is a UoW in progress, we can assume
+        #   that it is the active session. If not, we will start a new UoW and commit it after the operation
+        #   is complete.
+        own_current_uow = None
+        if not (current_uow and current_uow.in_progress):
+            own_current_uow = UnitOfWork()
+            own_current_uow.start()
+
+        uow = current_uow or own_current_uow
+        uow._add_to_identity_map(aggregate)
+
+        # If we started a UnitOfWork, commit it now
+        if own_current_uow:
+            own_current_uow.commit()
 
     def get(self, identifier: Identifier) -> BaseEventSourcedAggregate:
         """Retrieve a fully-formed Aggregate from a stream of Events.

src/protean/domain/__init__.py

@@ -949,18 +949,6 @@ def command_handler_for(self, command: BaseCommand) -> Optional[BaseCommandHandl
     ###################
     # Handling Events #
     ###################
-    def raise_(self, event: BaseEvent) -> None:
-        """Raise Domain Event in the stream specified in its options, or using the associated
-        aggregate's stream name.
-
-        Args:
-            event (BaseEvent): Event to record
-
-        Returns:
-            None: Returns nothing.
-        """
-        self.event_store.store.append(event)
-
     def handlers_for(self, event: BaseEvent) -> List[BaseEventHandler]:
         """Return Event Handlers listening to a specific event
 

tests/event/test_event_meta.py

@@ -1,5 +1,3 @@
-from uuid import uuid4
-
 import pytest
 
 from protean import BaseEvent, BaseEventSourcedAggregate
@@ -36,22 +34,6 @@ def test_event_definition_without_aggregate_or_stream(test_domain):
     }
 
 
-def test_event_definition_with_just_part_of(test_domain):
-    try:
-        identifier = str(uuid4())
-        test_domain.raise_(UserLoggedIn(user_id=identifier))
-    except IncorrectUsageError:
-        pytest.fail("Failed raising event when associated with Aggregate")
-
-
-def test_event_definition_with_just_stream(test_domain):
-    try:
-        identifier = str(uuid4())
-        test_domain.raise_(UserLoggedIn(user_id=identifier))
-    except IncorrectUsageError:
-        pytest.fail("Failed raising event when associated with Stream")
-
-
 def test_that_abstract_events_can_be_defined_without_aggregate_or_stream(test_domain):
     class AbstractEvent(BaseEvent):
         foo = String()

tests/event/test_raising_events.py

@@ -23,7 +23,10 @@ def test_raising_event(test_domain):
     test_domain.register(UserLoggedIn, stream_name="authentication")
 
     identifier = str(uuid4())
-    test_domain.raise_(UserLoggedIn(user_id=identifier))
+    user = User(id=identifier, email="[email protected]", name="Test User")
+    user.raise_(UserLoggedIn(user_id=identifier))
+
+    test_domain.repository_for(User).add(user)
 
     messages = test_domain.event_store.store.read("authentication")
 

tests/event_sourced_repository/test_add_uow.py

@@ -0,0 +1,37 @@
+import mock
+import pytest
+
+from protean import BaseEventSourcedAggregate
+from protean.fields import Identifier, String
+
+
+class User(BaseEventSourcedAggregate):
+    id = Identifier(identifier=True)
+    email = String()
+    name = String()
+
+
+@pytest.fixture(autouse=True)
+def register_elements(test_domain):
+    test_domain.register(User)
+    test_domain.init(traverse=False)
+
+
+@mock.patch("protean.core.repository.UnitOfWork.start")
+@mock.patch("protean.core.repository.UnitOfWork.commit")
+def test_that_method_is_enclosed_in_uow(mock_commit, mock_start, test_domain):
+    mock_parent = mock.Mock()
+
+    mock_parent.attach_mock(mock_start, "m1")
+    mock_parent.attach_mock(mock_commit, "m2")
+
+    with test_domain.domain_context():
+        user = User(id=1, email="[email protected]", name="John Doe")
+        test_domain.repository_for(User).add(user)
+
+    mock_parent.assert_has_calls(
+        [
+            mock.call.m1(),
+            mock.call.m2(),
+        ]
+    )