SubmissionDraft model initial commit

This is the first part of submission drafts that only account for file
uploads. Other types (body, media comments, etc) will be coming in
future commits.

Fixes COMMS-2050

Test Plan:
  - Migrate your database with this patchset checked out
    `bundle exec rake db:migrate:up VERSION=20190503151652`
  - Have some attachments in your database
  - Have a course with a studnet in it
  - Create and publish a new assignment in this course
  - Open the rails console, and notice that the submission for the
    student does not have any submission drafts associated with it

    ```
    s = Submission.last
    s.submission_drafts.empty?  # Should be true
    ```

  - Create a new submission draft with some attachments in the console,
    and notice that you can see the draft and attachmetns from the
    submission

    ```
    draft = SubmissionDraft.new(submission_attempt: 0)
    submission = Submission.last
    submission.submission_drafts << draft
    attachments = Attachment.limit 3
    draft.attachments = attachments

    submission.submission_drafts # Should show the new draft
    submission.submission_drafts.first.attachments # The attachments
    ```

  - From the web ui, submit the assignment as the student.

  - Back in the rails console, and notice that the submission draft
    has now been deleted

    ```
    submission.reload
    submission.submission_drafts # Should now be []
    SubmissionDraft.count # Should be 0
    SubmissionDraftAttachment.count # Should be 0
    ```

  - Notice that the attachments in the rails console have not been
    deleted.

    ```
    attachments.each(&:reload)
    attachments.map(&:persisted?) # Should all be true
    ```

  - Make sure you cannot create a draft that has a higher attempt then
    the  root submission:

    ```
    SubmissionDraft.create!(
      submisison: submission,
      submission_attempt: 0
    )  # Should raise a RecordInvalid error
    ```

  - Undo the database migration until this gets merged.
    `bundle exec rake db:migrate:down VERSION=20190503151652`

Change-Id: Ibedda3719e582b3aa67f049699603f3fc7cbc145
Reviewed-on: https://gerrit.instructure.com/192212
Tested-by: Jenkins
QA-Review: Matthew Lemon <mlemon@instructure.com>
Reviewed-by: Rob Orton <rob@instructure.com>
Product-Review: Landon Gilbert-Bland <lbland@instructure.com>

app/controllers/courses_controller.rb

@@ -2843,7 +2843,7 @@ class CoursesController < ApplicationController
       pg_scope.delete_all
       OriginalityReport.where(:submission_id => @fake_student.all_submissions).delete_all
       AnonymousOrModerationEvent.where(submission: @fake_student.all_submissions).destroy_all
-      @fake_student.all_submissions.preload(:all_submission_comments, :lti_result, :versions).destroy_all
+      @fake_student.all_submissions.preload(:all_submission_comments, :submission_drafts, :lti_result, :versions).destroy_all
       @fake_student.quiz_submissions.each{|qs| qs.events.destroy_all}
       @fake_student.quiz_submissions.destroy_all
 

app/models/assignment.rb

@@ -2003,10 +2003,12 @@ class Assignment < ActiveRecord::Base
         homework.turnitin_data[:eula_agreement_timestamp] = eula_timestamp if eula_timestamp.present?
         homework.with_versioning(:explicit => (homework.submission_type != "discussion_topic")) do
           if group
-            if student == original_student
-              homework.broadcast_group_submission
-            else
-              homework.save_without_broadcasting!
+            Submission.suspend_callbacks(:delete_submission_drafts!) do
+              if student == original_student
+                homework.broadcast_group_submission
+              else
+                homework.save_without_broadcasting!
+              end
             end
           else
             homework.save!

app/models/attachment.rb

@@ -66,6 +66,7 @@ class Attachment < ActiveRecord::Base
   belongs_to :user
   has_one :account_report
   has_one :media_object
+  has_many :submission_draft_attachments, inverse_of: :attachment
   has_many :submissions, -> { active }
   has_many :attachment_associations
   belongs_to :root_attachment, :class_name => 'Attachment'

app/models/submission.rb

@@ -99,6 +99,7 @@ class Submission < ActiveRecord::Base
   has_many :originality_reports
   has_one :rubric_assessment, -> { where(assessment_type: 'grading') }, as: :artifact, inverse_of: :artifact
   has_one :lti_result, inverse_of: :submission, class_name: 'Lti::Result', dependent: :destroy
+  has_many :submission_drafts, inverse_of: :submission, dependent: :destroy
 
   # we no longer link submission comments and conversations, but we haven't fixed up existing
   # linked conversations so this relation might be useful
@@ -313,6 +314,7 @@ class Submission < ActiveRecord::Base
   after_save :reset_regraded
   after_save :create_audit_event!
   after_save :handle_posted_at_changed, if: :saved_change_to_posted_at?
+  after_save :delete_submission_drafts!, if: :saved_change_to_attempt?
 
   def reset_regraded
     @regraded = false
@@ -2363,6 +2365,10 @@ class Submission < ActiveRecord::Base
     true
   end
 
+  def delete_submission_drafts!
+    self.submission_drafts.destroy_all
+  end
+
   def point_data?
     !!(self.score || self.grade)
   end

app/models/submission_draft.rb

@@ -0,0 +1,38 @@
+#
+# Copyright (C) 2019 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+class SubmissionDraft < ActiveRecord::Base
+  belongs_to :submission, inverse_of: :submission_drafts
+  has_many :submission_draft_attachments, inverse_of: :submission_draft, dependent: :delete_all
+  has_many :attachments, through: :submission_draft_attachments
+
+  validates :submission, presence: true
+  validates :submission_attempt, numericality: { only_integer: true }
+  validates :submission, uniqueness: { scope: :submission_attempt }
+  validate :submission_attempt_matches_submission
+
+  def submission_attempt_matches_submission
+    root_submission_attempt = self.submission&.attempt || 0
+    this_submission_attempt = self.submission_attempt || 0
+    if this_submission_attempt > root_submission_attempt
+      err = 'submission draft attempt cannot be larger then the submission attempt'
+      errors.add(:submission_draft_attempt, err)
+    end
+  end
+  private :submission_attempt_matches_submission
+end

app/models/submission_draft_attachment.rb

@@ -0,0 +1,26 @@
+#
+# Copyright (C) 2019 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+class SubmissionDraftAttachment < ActiveRecord::Base
+  belongs_to :submission_draft, inverse_of: :submission_draft_attachments
+  belongs_to :attachment, inverse_of: :submission_draft_attachments
+
+  validates :submission_draft, presence: true
+  validates :attachment, presence: true
+  validates :submission_draft, uniqueness: { scope: :attachment }
+end

db/migrate/20190503151652_create_submission_draft.rb

@@ -0,0 +1,39 @@
+#
+# Copyright (C) 2019 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+class CreateSubmissionDraft < ActiveRecord::Migration[5.1]
+  tag :predeploy
+
+  def change
+    create_table :submission_drafts do |t|
+      t.references :submission, limit: 8, foreign_key: true, index: true, null: false
+      t.integer :submission_attempt, index:true, null: false
+    end
+
+    # Attachments can be cross shard, so we can't use a proper foreign key for them
+    create_table :submission_draft_attachments do |t|
+      t.references :submission_draft, limit: 8, foreign_key: true, index: true, null: false
+      t.integer :attachment_id, limit: 8, index:true, null: false
+    end
+
+    add_index :submission_draft_attachments,
+      [:submission_draft_id, :attachment_id],
+      name: 'index_submission_draft_and_attachment_unique',
+      unique: true
+  end
+end

spec/lib/gradebook_grading_period_assignments_spec.rb

@@ -79,7 +79,7 @@ describe GradebookGradingPeriodAssignments do
       it "excludes deleted submissions" do
         assignment_in_gp2 = @example_course.assignments.create!(due_at: 1.day.from_now)
         assignment_in_gp2.destroy
-        assignment_in_gp2.submissions.preload(:all_submission_comments, :lti_result, :versions).map(&:destroy)
+        assignment_in_gp2.submissions.preload(:all_submission_comments, :lti_result, :versions, :submission_drafts).map(&:destroy)
         expect(hash[@period2.id]).not_to include(assignment_in_gp2.id.to_s)
       end
 

spec/models/submission_draft_attachment_spec.rb

@@ -0,0 +1,111 @@
+#
+# Copyright (C) 2019 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+require_relative '../spec_helper'
+require File.expand_path(File.dirname(__FILE__) + '/../sharding_spec_helper.rb')
+
+describe SubmissionDraftAttachment do
+  before :once do
+    @submission = submission_model
+    @submission_draft = SubmissionDraft.create!(
+      submission: @submission,
+      submission_attempt: @submission.attempt
+    )
+    @attachment = attachment_model
+    @submission_draft_attachment = SubmissionDraftAttachment.create!(
+      submission_draft: @submission_draft,
+      attachment: @attachment
+    )
+  end
+
+  it 'submission draft attachment has one attachment' do
+    expect(@submission_draft_attachment.attachment).to eq @attachment
+  end
+
+  it 'attachments can have multiple submission draft attachments' do
+    submission2 = submission_model
+    submission_draft2 = SubmissionDraft.create!(
+      submission: submission2,
+      submission_attempt: submission2.attempt
+    )
+    submission_draft_attachment2 = SubmissionDraftAttachment.create!(
+      submission_draft: submission_draft2,
+      attachment: @attachment
+    )
+    expect(@attachment.submission_draft_attachments.sort).to eq [
+      @submission_draft_attachment,
+      submission_draft_attachment2
+    ]
+  end
+
+  context 'validation' do
+    it 'will not let you have multiple of the same attachment to submission draft' do
+      expect{
+        SubmissionDraftAttachment.create!(
+          submission_draft: @submission_draft,
+          attachment: @attachment
+        )
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+
+    it 'requires an attachment' do
+      expect{
+        SubmissionDraftAttachment.create!(
+          submission_draft: @submission_draft,
+          attachment: nil
+        )
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+
+    it 'requires a submission draft' do
+      expect{
+        SubmissionDraftAttachment.create!(
+          submission_draft: nil,
+          attachment: @attachment
+        )
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+  end
+
+  context 'sharding' do
+    specs_require_sharding
+
+    before(:once) do
+      @shard1.activate { @attachment1 = attachment_model }
+      @shard2.activate { @attachment2 = attachment_model }
+      @shard1.activate do
+        @submission_draft.attachments = [@attachment1, @attachment2]
+        @submission_draft.save!
+      end
+    end
+
+    it 'can have attachments saved that are cross shard' do
+      @shard1.activate do
+        expect(
+          @submission_draft.attachments.pluck(:id).sort
+        ).to eq [@attachment1.id, @attachment2.global_id].sort
+      end
+
+      @shard2.activate do
+        expect(
+          @submission_draft.attachments.pluck(:id).sort
+        ).to eq [@attachment1.global_id, @attachment2.id].sort
+      end
+    end
+  end
+end

spec/models/submission_draft_spec.rb

@@ -0,0 +1,79 @@
+#
+# Copyright (C) 2019 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+require_relative '../spec_helper'
+
+RSpec.describe SubmissionDraft do
+  before(:once) do
+    @submission = submission_model
+    @submission_draft = SubmissionDraft.create!(
+      submission: @submission,
+      submission_attempt: @submission.attempt
+    )
+  end
+
+  describe 'attachments' do
+    before(:once) do
+      @attachment1 = attachment_model
+      @attachment2 = attachment_model
+      @attachment3 = attachment_model
+      @submission_draft.attachments = [@attachment1, @attachment2, @attachment3]
+    end
+
+    it 'can be accessed on a submission draft' do
+      expect(@submission_draft.attachments).to eq [@attachment1, @attachment2, @attachment3]
+    end
+
+    it 'can set different attachments on a submission draft' do
+      attachment4 = attachment_model
+      @submission_draft.attachments = [attachment4]
+      expect(@submission_draft.attachments).to eq [attachment4]
+    end
+
+    it 'are deleted if a submission draft is deleted' do
+      @submission_draft.destroy!
+      expect(SubmissionDraftAttachment.count).to eq 0
+    end
+  end
+
+  describe 'validation' do
+    it 'submission cannot be nil' do
+      expect{
+        SubmissionDraft.create!(submission: nil, submission_attempt: @submission.attempt)
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+
+    it 'submission_attempt cannot be nil' do
+      expect{
+        SubmissionDraft.create!(submission: @submission, submission_attempt: nil)
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+
+    it 'cannot have duplicate drafts for the same submission and attempt' do
+      expect{
+        SubmissionDraft.create!(submission: @submission, submission_attempt: @submission.attempt)
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+
+    it 'submission_attempt cannot be larger then the root submissions attempt' do
+      expect{
+        SubmissionDraft.create!(submission: @submission, submission_attempt: @submission.attempt + 1)
+      }.to raise_error(ActiveRecord::RecordInvalid)
+    end
+  end
+end

spec/models/submission_spec.rb

@@ -6269,6 +6269,61 @@ describe Submission do
     end
   end
 
+  describe '#submission_drafts' do
+    before(:once) do
+      @submission = Submission.find_by(user: @student)
+    end
+
+    it 'is empty by default' do
+      expect(@submission.submission_drafts).to eq []
+    end
+
+    describe 'with drafts for multiple attempts' do
+      before(:once) do
+        @submission = @assignment.submit_homework(@student, submission_type: 'online_text_entry', body: 'foo')
+        @draft1 = SubmissionDraft.new(submission: @submission, submission_attempt: 0)
+        @draft2 = SubmissionDraft.new(submission: @submission, submission_attempt: 1)
+        @submission.submission_drafts << @draft1
+        @submission.submission_drafts << @draft2
+      end
+
+      it 'can have drafts for different submission attempts' do
+        expect(@submission.submission_drafts.sort).to eq [@draft1, @draft2]
+      end
+
+      it 'deletes all drafts for all submission attempts when homework is submitted' do
+        @assignment.submit_homework(@student, submission_type: 'online_text_entry', body: 'foo')
+        @submission.reload
+        expect(@submission.submission_drafts).to eq []
+        expect(SubmissionDraft.count).to be 0
+      end
+    end
+
+    describe 'with attachments' do
+      before(:once) do
+        @attachment1 = attachment_model
+        @attachment2 = attachment_model
+        @submission_draft = SubmissionDraft.create!(
+          submission: @submission,
+          submission_attempt: 0
+        )
+        @submission_draft.attachments = [@attachment1, @attachment2]
+      end
+
+      it 'can access the attachments' do
+        expect(@submission.submission_drafts.first.attachments.sort).to eq [@attachment1, @attachment2]
+      end
+
+      it 'will cascade deletes to SubmissionDraftAttachments when homework is submitted' do
+        @assignment.submit_homework(@student, submission_type: 'online_text_entry', body: 'foo')
+        @submission.reload
+        expect(@submission.submission_drafts).to eq []
+        expect(SubmissionDraft.count).to be 0
+        expect(SubmissionDraftAttachment.count).to be 0
+      end
+    end
+  end
+
   describe "posting and unposting" do
     before(:each) do
       @assignment.course.enable_feature!(:post_policies)