feat: expose effective function incumbency contracts

tests/test_directory.py

@@ -133,6 +133,100 @@ class IdmDirectoryDelegationTests(unittest.TestCase):
                 )
                 self.assertEqual(expected_ids, tuple(item.id for item in assignments))
 
+    def test_reverse_lookup_returns_only_effective_function_assignments(self) -> None:
+        now = datetime.now(timezone.utc)
+        active = IdmOrganizationFunctionAssignment(
+            id="active-function-holder",
+            tenant_id="tenant-1",
+            identity_id="identity-active",
+            account_id="account-active",
+            function_id="function-1",
+            organization_unit_id="unit-1",
+            source="direct",
+            is_active=True,
+            settings={},
+        )
+        expired = IdmOrganizationFunctionAssignment(
+            id="expired-function-holder",
+            tenant_id="tenant-1",
+            identity_id="identity-expired",
+            function_id="function-1",
+            organization_unit_id="unit-1",
+            source="direct",
+            is_active=True,
+            valid_until=now - timedelta(minutes=1),
+            settings={},
+        )
+        other_tenant = IdmOrganizationFunctionAssignment(
+            id="other-tenant-holder",
+            tenant_id="tenant-2",
+            identity_id="identity-other",
+            function_id="function-1",
+            organization_unit_id="unit-1",
+            source="direct",
+            is_active=True,
+            settings={},
+        )
+        with self.database.session() as session:
+            session.add_all((active, expired, other_tenant))
+            session.commit()
+
+        assignments = self.directory.organization_function_assignments_for_function(
+            "function-1",
+            tenant_id="tenant-1",
+        )
+
+        self.assertEqual(
+            ("active-function-holder",),
+            tuple(item.id for item in assignments),
+        )
+
+    def test_batch_incumbency_reports_vacancy_and_honors_effective_time(
+        self,
+    ) -> None:
+        boundary = datetime.now(timezone.utc)
+        assignment = IdmOrganizationFunctionAssignment(
+            id="bounded-holder",
+            tenant_id="tenant-1",
+            identity_id="identity-bounded",
+            account_id="account-bounded",
+            function_id="function-1",
+            organization_unit_id="unit-1",
+            source="direct",
+            is_active=True,
+            valid_from=boundary - timedelta(hours=1),
+            valid_until=boundary + timedelta(hours=1),
+            settings={},
+        )
+        with self.database.session() as session:
+            session.add(assignment)
+            session.commit()
+
+        current = self.directory.organization_function_incumbencies(
+            ("function-1", "function-2"),
+            tenant_id="tenant-1",
+            effective_at=boundary,
+        )
+        later = self.directory.organization_function_incumbencies(
+            ("function-1",),
+            tenant_id="tenant-1",
+            effective_at=boundary + timedelta(hours=2),
+        )
+
+        self.assertEqual(
+            ("bounded-holder",),
+            tuple(item.id for item in current["function-1"].assignments),
+        )
+        self.assertFalse(current["function-1"].vacant)
+        self.assertTrue(current["function-2"].vacant)
+        self.assertTrue(later["function-1"].vacant)
+
+        with self.assertRaisesRegex(ValueError, "another tenant"):
+            self.directory.organization_function_incumbencies(
+                ("function-1",),
+                tenant_id="tenant-2",
+            )
+
 
 if __name__ == "__main__":
     unittest.main()