feat(cache): add targeted server-side response caching

apps/workspaces/tests/test_api_permissions.py

@@ -1,6 +1,8 @@
 from types import SimpleNamespace
 
+from django.core.cache import cache
 from django.test import TestCase
+from rest_framework.test import APITestCase
 
 from apps.users.models import User
 from apps.workspaces.api.permissions import (
@@ -144,3 +146,46 @@ class WorkspacePermissionTests(TestCase):
                 object(),
             )
         )
+
+
+class WorkspaceMembershipCacheTests(APITestCase):
+    @classmethod
+    def setUpTestData(cls):
+        cls.owner = User.objects.create_user(mobile="09127770031", password="secret123")
+        cls.member = User.objects.create_user(mobile="09127770032", password="secret123")
+        cls.workspace = Workspace.objects.create(name="Membership Cache", owner=cls.owner)
+        cls.membership = WorkspaceMembership.objects.create(
+            workspace=cls.workspace,
+            user=cls.member,
+            role=WorkspaceMembership.Role.MEMBER,
+            is_active=True,
+        )
+
+    def setUp(self):
+        cache.clear()
+        self.client.force_authenticate(user=self.owner)
+
+    def test_membership_list_cache_invalidates_after_membership_save(self):
+        params = {"workspace": str(self.workspace.id)}
+
+        first_response = self.client.get("/api/workspace-memberships/", params)
+        self.assertEqual(first_response.status_code, 200)
+        target = next(item for item in first_response.data["items"] if item["id"] == str(self.membership.id))
+        self.assertEqual(target["role"], WorkspaceMembership.Role.MEMBER)
+
+        WorkspaceMembership.objects.filter(id=self.membership.id).update(role=WorkspaceMembership.Role.GUEST)
+
+        cached_response = self.client.get("/api/workspace-memberships/", params)
+        self.assertEqual(cached_response.status_code, 200)
+        target = next(item for item in cached_response.data["items"] if item["id"] == str(self.membership.id))
+        self.assertEqual(target["role"], WorkspaceMembership.Role.MEMBER)
+
+        self.membership.refresh_from_db()
+        self.membership.is_active = False
+        self.membership.save(update_fields=["is_active"])
+
+        fresh_response = self.client.get("/api/workspace-memberships/", params)
+        self.assertEqual(fresh_response.status_code, 200)
+        target = next(item for item in fresh_response.data["items"] if item["id"] == str(self.membership.id))
+        self.assertEqual(target["role"], WorkspaceMembership.Role.GUEST)
+        self.assertFalse(target["is_active"])