feat: add membership management tests; implement session and repository stubs for member addition and duplicate checks

tests/services/test_organization_service.py

@@ -1,6 +1,7 @@
 """Unit tests for OrganizationService."""
 from __future__ import annotations
 
+from typing import cast
 from unittest.mock import MagicMock
 
 import pytest  # type: ignore[import-not-found]
@@ -14,6 +15,7 @@ from app.services.organization_service import (
     OrganizationContext,
     OrganizationContextMissingError,
     OrganizationForbiddenError,
+    OrganizationMemberAlreadyExistsError,
     OrganizationService,
 )
 
@@ -47,6 +49,40 @@ def make_membership(role: OrganizationRole, *, organization_id: int = 1, user_id
     return membership
 
 
+class SessionStub:
+    """Minimal async session stub capturing writes."""
+
+    def __init__(self) -> None:
+        self.added: list[OrganizationMember] = []
+        self.committed: bool = False
+        self.refreshed: list[OrganizationMember] = []
+
+    def add(self, obj: OrganizationMember) -> None:
+        self.added.append(obj)
+
+    async def commit(self) -> None:
+        self.committed = True
+
+    async def refresh(self, obj: OrganizationMember) -> None:
+        self.refreshed.append(obj)
+
+
+class MembershipRepositoryStub(OrganizationRepository):
+    """Repository stub that can emulate duplicate checks for add_member."""
+
+    def __init__(self, memberships: dict[tuple[int, int], OrganizationMember] | None = None) -> None:
+        self._session_stub = SessionStub()
+        super().__init__(session=cast(AsyncSession, self._session_stub))
+        self._memberships = memberships or {}
+
+    @property
+    def session_stub(self) -> SessionStub:
+        return self._session_stub
+
+    async def get_membership(self, organization_id: int, user_id: int) -> OrganizationMember | None:
+        return self._memberships.get((organization_id, user_id))
+
+
 @pytest.mark.asyncio
 async def test_get_context_success() -> None:
     membership = make_membership(OrganizationRole.MANAGER)
@@ -96,4 +132,63 @@ def test_member_must_own_entity() -> None:
         service.ensure_member_owns_entity(context=context, owner_id=999)
 
     # Same owner should pass silently.
-    service.ensure_member_owns_entity(context=context, owner_id=membership.user_id)
+    service.ensure_member_owns_entity(context=context, owner_id=membership.user_id)
+
+
+@pytest.mark.asyncio
+async def test_add_member_succeeds_for_owner() -> None:
+    owner_membership = make_membership(OrganizationRole.OWNER, organization_id=7, user_id=1)
+    organization = owner_membership.organization
+    assert organization is not None
+    context = OrganizationContext(organization=organization, membership=owner_membership)
+
+    repo = MembershipRepositoryStub()
+    service = OrganizationService(repo)
+
+    result = await service.add_member(context=context, user_id=42, role=OrganizationRole.MANAGER)
+
+    assert result.organization_id == organization.id
+    assert result.user_id == 42
+    assert result.role == OrganizationRole.MANAGER
+
+    session_stub = repo.session_stub
+    assert session_stub.committed is True
+    assert session_stub.added and session_stub.added[0] is result
+    assert session_stub.refreshed and session_stub.refreshed[0] is result
+
+
+@pytest.mark.asyncio
+async def test_add_member_rejects_duplicate_membership() -> None:
+    owner_membership = make_membership(OrganizationRole.OWNER, organization_id=5, user_id=10)
+    organization = owner_membership.organization
+    assert organization is not None
+    context = OrganizationContext(organization=organization, membership=owner_membership)
+
+    duplicate_user_id = 55
+    existing = OrganizationMember(
+        organization_id=organization.id,
+        user_id=duplicate_user_id,
+        role=OrganizationRole.MEMBER,
+    )
+    repo = MembershipRepositoryStub({(organization.id, duplicate_user_id): existing})
+    service = OrganizationService(repo)
+
+    with pytest.raises(OrganizationMemberAlreadyExistsError):
+        await service.add_member(context=context, user_id=duplicate_user_id, role=OrganizationRole.MANAGER)
+
+
+@pytest.mark.asyncio
+async def test_add_member_requires_privileged_role() -> None:
+    member_context = make_membership(OrganizationRole.MEMBER, organization_id=3, user_id=77)
+    organization = member_context.organization
+    assert organization is not None
+    context = OrganizationContext(organization=organization, membership=member_context)
+
+    repo = MembershipRepositoryStub()
+    service = OrganizationService(repo)
+
+    with pytest.raises(OrganizationForbiddenError):
+        await service.add_member(context=context, user_id=99, role=OrganizationRole.MANAGER)
+
+    # Ensure DB work not attempted when permissions fail.
+    assert repo.session_stub.committed is False