Remove assignments w/ sub assignments from undated items

closes VICE-4492
flag=discussion_checkpoints

Test plan:
- Go to SiteAdmin -> Feature Options and enable
the Discussion Checkpoints feature flag
- Create a course and enroll yourself as teacher
or student; take a note of the course id
- Create a graded discussion with checkpoints
and add due dates
- Create a graded discussion with checkpoints
but do not add due dates
- Get undated assignments from the Calendar API
http://<canvas url>/api/v1/calendar_events?
type=assignment&context_codes[]=course_<course id>&undated=1
- Verify that response is an empty array
- Repeat the API call for type=sub_assignment
- Verify that the two undated checkpoints are returned

Change-Id: I1630561f5817fb39acd8f7534b873b6d6825c56a
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/354994
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Chawn Neal <chawn.neal@instructure.com>
QA-Review: Omar Soto-Fortuño <omar.soto@instructure.com>
Product-Review: Omar Soto-Fortuño <omar.soto@instructure.com>

app/controllers/calendar_events_api_controller.rb

@@ -1670,6 +1670,13 @@ class CalendarEventsApiController < ApplicationController
       # specific people, sections, etc. This applies the base assignment due_at for ordering
       # as a more sane default then natural DB order. No, it isn't perfect but much better.
       scope = assignment_context_scope(user, sub_assignment:)
+
+      # exclude undated assignments with sub assignments because the
+      # parent assignment does not have due date, only the sub assignments do
+      if @undated && !sub_assignment && discussion_checkpoints_enabled?
+        scope = scope.where(has_sub_assignments: false)
+      end
+
       next unless scope
 
       scope = scope.order(:due_at, :id)

spec/apis/v1/calendar_events_api_spec.rb

@@ -27,6 +27,16 @@ describe CalendarEventsApiController, type: :request do
     @me = @user
   end
 
+  def create_checkpoint(topic:, type: "reply_to_topic", due_at: nil, points_possible: 5)
+    checkpoint_label = (type == "reply_to_topic") ? CheckpointLabels::REPLY_TO_TOPIC : CheckpointLabels::REPLY_TO_ENTRY
+    Checkpoints::DiscussionCheckpointCreatorService.call(
+      discussion_topic: topic,
+      checkpoint_label:,
+      dates: due_at.nil? ? [] : [{ type: "everyone", due_at: }],
+      points_possible:
+    )
+  end
+
   context "events" do
     expected_fields = %w[
       all_context_codes
@@ -2843,19 +2853,38 @@ describe CalendarEventsApiController, type: :request do
       expect(json.size).to be 9 # first context has no events
     end
 
-    it "returns undated assignments" do
-      @course.assignments.create(title: "undated")
-      @course.assignments.create(title: "dated", due_at: "2012-01-08 12:00:00")
-      json = api_call(:get, "/api/v1/calendar_events?type=assignment&undated=1&context_codes[]=course_#{@course.id}", {
-                        controller: "calendar_events_api",
-                        action: "index",
-                        format: "json",
-                        type: "assignment",
-                        context_codes: ["course_#{@course.id}"],
-                        undated: "1"
-                      })
-      expect(json.size).to be 1
-      expect(json.first["due_at"]).to be_nil
+    context "undated assignments" do
+      it "returns undated assignments" do
+        @course.assignments.create(title: "undated")
+        @course.assignments.create(title: "dated", due_at: "2012-01-08 12:00:00")
+        json = api_call(:get, "/api/v1/calendar_events?type=assignment&undated=1&context_codes[]=course_#{@course.id}", {
+                          controller: "calendar_events_api",
+                          action: "index",
+                          format: "json",
+                          type: "assignment",
+                          context_codes: ["course_#{@course.id}"],
+                          undated: "1"
+                        })
+        expect(json.size).to be 1
+        expect(json.first["due_at"]).to be_nil
+      end
+
+      it "does not return undated assignments associated with discussions with checkpoints" do
+        @course.root_account.enable_feature!(:discussion_checkpoints)
+        topic = DiscussionTopic.create_graded_topic!(course: @course, title: "#{@course.id} - graded topic with checkpoints")
+        create_checkpoint(topic:, due_at: "2024-08-01 12:00:00")
+        create_checkpoint(topic:, type: "reply_to_entry", due_at: "2024-08-02 12:00:00")
+
+        json = api_call(:get, "/api/v1/calendar_events", {
+                          controller: "calendar_events_api",
+                          action: "index",
+                          format: "json",
+                          type: "assignment",
+                          context_codes: ["course_#{@course.id}"],
+                          undated: "1"
+                        })
+        expect(json.size).to be 0
+      end
     end
 
     context "mark_submitted_assignments" do
@@ -4234,16 +4263,6 @@ describe CalendarEventsApiController, type: :request do
       @checkpoint_2 = create_checkpoint(topic: @topic, type: "reply_to_entry", due_at: "2024-08-02 12:00:00")
     end
 
-    def create_checkpoint(topic:, type: "reply_to_topic", due_at: nil, points_possible: 5)
-      checkpoint_label = (type == "reply_to_topic") ? CheckpointLabels::REPLY_TO_TOPIC : CheckpointLabels::REPLY_TO_ENTRY
-      Checkpoints::DiscussionCheckpointCreatorService.call(
-        discussion_topic: topic,
-        checkpoint_label:,
-        dates: due_at.nil? ? [] : [{ type: "everyone", due_at: }],
-        points_possible:
-      )
-    end
-
     expected_sub_assignment_fields = %w[
       all_day
       all_day_date