DA - remove deleted assignments from sql view

fixes CNVS-15511

test plan:
  - turn DA off and make an assignment then delete the assignment
  - note the assignment's id
  - open the rails console and run this
    - "AssignmentStudentVisibility.where(assignment_id: XXXXX)"
    - instead of XXXXX, you should write the assignment's id
    - the result of that command should be an empry array => []

Change-Id: I2f09560ce46bd4682e9bf671b4c116508a6f4b49
Reviewed-on: https://gerrit.instructure.com/41114
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Simon Williams <simon@instructure.com>
QA-Review: Amber Taniuchi <amber@instructure.com>
Product-Review: Simon Williams <simon@instructure.com>

db/migrate/20140915174918_remove_deleted_from_assignment_student_visibility_view.rb

@@ -0,0 +1,88 @@
+class RemoveDeletedFromAssignmentStudentVisibilityView < ActiveRecord::Migration
+  tag :predeploy
+
+  def up
+    self.connection.execute "DROP VIEW assignment_student_visibilities;"
+    self.connection.execute %Q(CREATE VIEW assignment_student_visibilities AS
+      SELECT DISTINCT a.id as assignment_id,
+      e.user_id as user_id,
+      c.id as course_id
+
+      FROM assignments a
+
+      JOIN courses c
+        ON a.context_id = c.id
+        AND a.context_type = 'Course'
+
+      JOIN enrollments e
+        ON e.course_id = c.id
+        AND e.type IN ('StudentEnrollment', 'StudentViewEnrollment')
+        AND e.workflow_state != 'deleted'
+
+      JOIN course_sections cs
+        ON cs.course_id = c.id
+        AND e.course_section_id = cs.id
+
+      LEFT JOIN assignment_overrides ao
+        ON ao.assignment_id = a.id
+        AND ao.workflow_state = 'active'
+        AND ao.set_type = 'CourseSection'
+        AND ao.set_id = cs.id
+
+      LEFT JOIN submissions s
+        ON s.user_id = e.user_id
+        AND s.assignment_id = a.id
+        AND s.score IS NOT NULL
+
+      WHERE a.workflow_state NOT IN ('deleted','unpublished')
+        AND(
+          ( a.only_visible_to_overrides = 'true' AND (ao.id IS NOT NULL OR s.id IS NOT NULL))
+          OR (COALESCE(a.only_visible_to_overrides, 'false') = 'false')
+        )
+      )
+  end
+
+  def down
+    self.connection.execute "DROP VIEW assignment_student_visibilities;"
+    self.connection.execute %Q(CREATE VIEW assignment_student_visibilities AS
+      SELECT DISTINCT a.id as assignment_id,
+      e.user_id as user_id,
+      c.id as course_id
+
+      FROM assignments a
+
+      JOIN courses c
+        ON a.context_id = c.id
+        AND a.context_type = 'Course'
+
+      JOIN enrollments e
+        ON e.course_id = c.id
+        AND e.type IN ('StudentEnrollment', 'StudentViewEnrollment')
+        AND e.workflow_state != 'deleted'
+
+      JOIN course_sections cs
+        ON cs.course_id = c.id
+        AND e.course_section_id = cs.id
+
+      LEFT JOIN assignment_overrides ao
+        ON ao.assignment_id = a.id
+        AND ao.workflow_state = 'active'
+        AND ao.set_type = 'CourseSection'
+        AND ao.set_id = cs.id
+
+      LEFT JOIN submissions s
+        ON s.user_id = e.user_id
+        AND s.assignment_id = a.id
+        AND s.score IS NOT NULL
+
+      WHERE a.workflow_state NOT IN ('deleted','unpublished')
+        AND ( a.only_visible_to_overrides = 'true'
+          AND (ao.id IS NOT NULL
+            OR s.id IS NOT NULL
+          )
+        ) OR (
+          COALESCE(a.only_visible_to_overrides, 'false') = 'false'
+        )
+      )
+  end
+end

spec/models/assignment_student_visibility_spec.rb

@@ -215,6 +215,10 @@ describe "differentiated_assignments" do
         it "should show the assignment to the user" do
           ensure_user_sees_assignment
         end
+        it "should not show deleted assignments" do
+          @assignment.destroy
+          ensure_user_does_not_see_assignment
+        end
       end
       context "user in section with override" do
         before{enroller_user_in_section(@section_foo)}