✨(api) allow on-demand page size on the order and enrollment endpoints

The order and enrollment endpoints are used by the frontend to build
a view mixing both objects. For this, the frontend needs to be able
to customize the number of items returned by page. We fix the max
size of the page to 100 items for security reasons.

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to
 
 ## Added
 
+- Allow on-demand page size on the order and enrollment endpoints
 - Add yarn cli to generate joanie api client in TypeScript
 
 ### Removed

src/backend/joanie/core/api.py

@@ -47,7 +47,8 @@ class Pagination(pagination.PageNumberPagination):
     """Pagination to display no more than 100 objects per page sorted by creation date."""
 
     ordering = "-created_on"
-    page_size = 100
+    max_page_size = 100
+    page_size_query_param = "page_size"
 
 
 class CourseRunViewSet(mixins.RetrieveModelMixin, viewsets.GenericViewSet):

src/backend/joanie/tests/core/test_api_enrollment.py

@@ -220,6 +220,57 @@ def test_api_enrollment_read_list_authenticated(self):
             },
         )
 
+    def test_api_enrollment_read_list_pagination(self):
+        """Pagination should work as expected."""
+        user = factories.UserFactory()
+        enrollments = [
+            factories.EnrollmentFactory(
+                user=user, course_run=self.create_opened_course_run(is_listed=True)
+            )
+            for _ in range(3)
+        ]
+        enrollment_ids = [str(enrollment.id) for enrollment in enrollments]
+
+        # The user can see his/her enrollment
+        token = self.get_user_token(user.username)
+
+        response = self.client.get(
+            "/api/v1.0/enrollments/?page_size=2",
+            HTTP_AUTHORIZATION=f"Bearer {token}",
+        )
+
+        self.assertEqual(response.status_code, 200)
+        content = response.json()
+        self.assertEqual(content["count"], 3)
+        self.assertEqual(
+            content["next"],
+            "http://testserver/api/v1.0/enrollments/?page=2&page_size=2",
+        )
+        self.assertIsNone(content["previous"])
+
+        self.assertEqual(len(content["results"]), 2)
+        for item in content["results"]:
+            enrollment_ids.remove(item["id"])
+
+        # Get page 2
+        response = self.client.get(
+            "/api/v1.0/enrollments/?page_size=2&page=2",
+            HTTP_AUTHORIZATION=f"Bearer {token}",
+        )
+
+        self.assertEqual(response.status_code, 200)
+        content = response.json()
+
+        self.assertEqual(content["count"], 3)
+        self.assertIsNone(content["next"])
+        self.assertEqual(
+            content["previous"], "http://testserver/api/v1.0/enrollments/?page_size=2"
+        )
+
+        self.assertEqual(len(content["results"]), 1)
+        enrollment_ids.remove(content["results"][0]["id"])
+        self.assertEqual(enrollment_ids, [])
+
     def test_api_enrollment_read_list_filtered_by_course_run_id(self):
         """
         Authenticated users retrieving the list of enrollments should be able to filter

src/backend/joanie/tests/core/test_api_order.py

@@ -127,6 +127,50 @@ def test_api_order_read_list_authenticated(self):
             },
         )
 
+    def test_api_order_read_list_pagination(self):
+        """Pagination should work as expected."""
+        user = factories.UserFactory()
+        orders = factories.OrderFactory.create_batch(3, owner=user)
+        order_ids = [str(order.id) for order in orders]
+
+        # The owner can see his/her order
+        token = self.get_user_token(user.username)
+
+        response = self.client.get(
+            "/api/v1.0/orders/?page_size=2",
+            HTTP_AUTHORIZATION=f"Bearer {token}",
+        )
+
+        self.assertEqual(response.status_code, 200)
+        content = response.json()
+        self.assertEqual(content["count"], 3)
+        self.assertEqual(
+            content["next"], "http://testserver/api/v1.0/orders/?page=2&page_size=2"
+        )
+        self.assertIsNone(content["previous"])
+
+        self.assertEqual(len(content["results"]), 2)
+        for item in content["results"]:
+            order_ids.remove(item["id"])
+
+        # Get page 2
+        response = self.client.get(
+            "/api/v1.0/orders/?page_size=2&page=2", HTTP_AUTHORIZATION=f"Bearer {token}"
+        )
+
+        self.assertEqual(response.status_code, 200)
+        content = response.json()
+
+        self.assertEqual(content["count"], 3)
+        self.assertIsNone(content["next"])
+        self.assertEqual(
+            content["previous"], "http://testserver/api/v1.0/orders/?page_size=2"
+        )
+
+        self.assertEqual(len(content["results"]), 1)
+        order_ids.remove(content["results"][0]["id"])
+        self.assertEqual(order_ids, [])
+
     def test_api_order_read_list_filtered_by_product_id(self):
         """Authenticated user should be able to filter their orders by product id."""
         [product_1, product_2] = factories.ProductFactory.create_batch(2)