Add 'lti_user_id' to submission live events

Closes PLAT-2824

Test Plan:

- Create a submission with an attachment as a student in an
  assignmetn associated with a plagiarism detection tool.
- Verify that the live event emitted contains an `lti_user_id`
  that matches the `lti_context_id` of the student.
- As a teacher click the `resubmit to plagiarism tool` button in
  speedgrader. Verify that the live event emitted contains the
  `lti_user_id` filed set to the student's `lti_context_id`.

Change-Id: I26d1da652f22ef7fd1cde361688704598db29fa7
Reviewed-on: https://gerrit.instructure.com/125503
Reviewed-by: Nathan Mills <nathanm@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Tested-by: Jenkins
Reviewed-by: Cody Cutrer <cody@instructure.com>
Product-Review: Weston Dransfield <wdransfield@instructure.com>

app/models/assignment.rb

@@ -1656,7 +1656,7 @@ class Assignment < ActiveRecord::Base
           :group => group
         })
         homework.submitted_at = Time.zone.now
-
+        homework.lti_user_id = Lti::Asset.opaque_identifier_for(student)
         homework.with_versioning(:explicit => (homework.submission_type != "discussion_topic")) do
           if group
             if student == original_student

db/migrate/20170911132849_add_lti_student_id_to_submission.rb

@@ -0,0 +1,24 @@
+#
+# Copyright (C) 2015 - 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 AddLtiStudentIdToSubmission < ActiveRecord::Migration[5.0]
+  tag :predeploy
+
+  def change
+    add_column :submissions, :lti_user_id, :string
+  end
+end

doc/api/live_events.md

@@ -332,6 +332,7 @@ by `asset_type` and `asset_id`.
 | `submission_id` | The Canvas id of the new submission. |
 | `assignment_id` | The Canvas id of the assignment being submitted. |
 | `user_id` | The Canvas id of the user associated with the submission. |
+| `lti_user_id` | The Lti id of the user associated with the submission. |
 | `submitted_at` | The timestamp when the assignment was submitted. |
 | `updated_at` | The time at which this assignment was last modified in any way |
 | `score` | The raw score |
@@ -350,6 +351,7 @@ by `asset_type` and `asset_id`.
 | `submission_id` | The Canvas id of the new submission. |
 | `assignment_id` | The Canvas id of the assignment being submitted. |
 | `user_id` | The Canvas id of the user associated with the submission. |
+| `lti_user_id` | The Lti id of the user associated with the submission. |
 | `submitted_at` | The timestamp when the assignment was submitted. |
 | `updated_at` | The time at which this assignment was last modified in any way |
 | `score` | The raw score |
@@ -368,6 +370,7 @@ by `asset_type` and `asset_id`.
 | `submission_id` | The Canvas id of the new submission. |
 | `assignment_id` | The Canvas id of the assignment being submitted. |
 | `user_id` | The Canvas id of the user associated with the submission. |
+| `lti_user_id` | The Lti id of the user associated with the submission. |
 | `submitted_at` | The timestamp when the assignment was submitted. |
 | `updated_at` | The time at which this assignment was last modified in any way |
 | `score` | The raw score |

lib/canvas/live_events.rb

@@ -178,6 +178,7 @@ module Canvas::LiveEvents
       assignment_id: submission.global_assignment_id,
       user_id: submission.global_user_id,
       submitted_at: submission.submitted_at,
+      lti_user_id: submission.lti_user_id,
       graded_at: submission.graded_at,
       updated_at: submission.updated_at,
       score: submission.score,

spec/lib/canvas/live_events_spec.rb

@@ -345,6 +345,7 @@ describe Canvas::LiveEvents do
       expect_event('submission_created',
         hash_including(
           user_id: @student.global_id.to_s,
+          lti_user_id: @student.lti_context_id,
           assignment_id: submission.global_assignment_id.to_s,
           lti_assignment_id: submission.assignment.lti_context_id.to_s
         ))
@@ -360,6 +361,7 @@ describe Canvas::LiveEvents do
       expect_event('submission_updated',
         hash_including(
           user_id: @student.global_id.to_s,
+          lti_user_id: @student.lti_context_id,
           assignment_id: submission.global_assignment_id.to_s,
           lti_assignment_id: submission.assignment.lti_context_id.to_s
         ))
@@ -374,6 +376,7 @@ describe Canvas::LiveEvents do
       expect_event('plagiarism_resubmit',
         hash_including(
           user_id: @student.global_id.to_s,
+          lti_user_id: @student.lti_context_id,
           assignment_id: submission.global_assignment_id.to_s,
           lti_assignment_id: submission.assignment.lti_context_id.to_s
         ))

spec/models/assignment_spec.rb

@@ -1400,6 +1400,12 @@ describe Assignment do
       expect(s3.late_policy_status).to eq "late"
       expect(s3.seconds_late_override).to eq 120
     end
+
+    it "sets the submission's 'lti_user_id'" do
+      setup_assignment_without_submission
+      submission = @a.submit_homework(@user)
+      expect(submission.lti_user_id).to eq @user.lti_context_id
+    end
   end
 
   describe "muting" do

spec/selenium/notifications_spec.rb

@@ -96,7 +96,7 @@ describe "Notifications" do
 
         fj('.ui-tabs-anchor:contains("Plain Text")').click
         expect(f('.message-body')).to include_text('Anonymous User just made a new comment on the '\
-                                                   'submission for User for assignment')
+                                                   "submission for #{@student.reload.short_name} for assignment")
       end
 
       context "observer notifications" do