improve the enrollments check in the missing policy applicator

The activerecord query in ‘recently_missing_submissions‘
now uses a join between courses and enrollments to only
apply the condition to the right submissions.

fixes EVAL-1547
flag=none

test plan:
- Create a course (A) with at least one student enrolled.
- Create a course (B) with the same student enrolled.
- Create an assignment for both courses (A) and (B)
  with a due date of one day before the current date.
- Conclude the enrollment for the student to course (B).
- Enable 'Automatically apply grade for missing submissions'
  late policy for both courses (A) and (B).
- Wait 5 minutes to get the 'apply_missing_deductions'
  cronjob executed.
- Notice that only the submission (A) is affected by the
  late policy.

Change-Id: Ic8386f713117826f24dc414a6ff92f9565d09b1e
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/263274
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Spencer Olson <solson@instructure.com>
Reviewed-by: Adrian Packel <apackel@instructure.com>
QA-Review: Kai Bjorkman <kbjorkman@instructure.com>
Product-Review: Syed Hussain <shussain@instructure.com>

lib/missing_policy_applicator.rb

@@ -35,13 +35,14 @@ class MissingPolicyApplicator
 
   def recently_missing_submissions
     now = Time.zone.now
-    Submission.active.
-      joins(assignment: {course: :late_policy}).
-      eager_load(:grading_period, assignment: [:post_policy, { course: [:late_policy, :default_post_policy] }]).
-      for_enrollments(Enrollment.all_active_or_pending).
-      merge(Assignment.published).
-      missing.
-      where(score: nil, grade: nil, cached_due_date: 1.day.ago(now)..now,
+    Submission.active
+      .joins(assignment: {course: [:late_policy, :enrollments]})
+      .where("enrollments.user_id = submissions.user_id")
+      .eager_load(:grading_period, assignment: [:post_policy, { course: [:late_policy, :default_post_policy] }])
+      .merge(Assignment.published)
+      .merge(Enrollment.all_active_or_pending)
+      .missing
+      .where(score: nil, grade: nil, cached_due_date: 1.day.ago(now)..now,
             late_policies: { missing_submission_deduction_enabled: true })
   end
 

spec/lib/missing_policy_applicator_spec.rb

@@ -267,6 +267,34 @@ describe MissingPolicyApplicator do
       expect { applicator.apply_missing_deductions }.not_to(change { submission.reload.score })
     end
 
+    it 'does not change the grade on missing submissions for concluded enrollments in other courses' do
+      c1 = course_with_student(active_all: true).course
+      c2 = course_with_student(user: @student, active_all: true).course
+      c1.assignments.create!(
+        valid_assignment_attributes.merge(grading_type: 'letter_grade', due_at: 1.hour.ago(now))
+      )
+      c2.assignments.create!(
+        valid_assignment_attributes.merge(grading_type: 'letter_grade', due_at: 1.hour.ago(now))
+      )
+      c2.student_enrollments.find_by(user_id: @student).conclude
+      LatePolicy.create!(
+        course_id: c1.id,
+        missing_submission_deduction_enabled: true,
+        missing_submission_deduction: 75
+      )
+      LatePolicy.create!(
+        course_id: c2.id,
+        missing_submission_deduction_enabled: true,
+        missing_submission_deduction: 75
+      )
+      s1 = c1.submissions.find_by(user_id: @student)
+      s1.update_columns(score: nil, grade: nil)
+
+      s2 = c2.submissions.find_by(user_id: @student)
+      s2.update_columns(score: nil, grade: nil)
+      expect { applicator.apply_missing_deductions }.not_to change { s2.reload.grade }
+    end
+
     it 'does not change the grade on missing submissions for concluded students' do
       create_recent_assignment
       @course.student_enrollments.find_by(user_id: @student).conclude