create results for manually graded LTI submissions

Thanks Xander for the rest of this commit message :D

refs INTEROP-7100
flag=none

why:
* all submissions with scores should have matching Lti::Results
* a previous commit covered the case where an existing assignment with
submissions is associated with an LTI tool
* this case is where an LTI assignment is manually graded by a teacher,
without the tool having sent scores back

test plan
* without this commit checked out:
* create an assignment associated with a LTI 1.3 tool
* manually grade a student for this assignment, without them launching
the tool or submitting anything from the tool
* check that an Lti::Result has been created following instructions
above
* without this commit, there should be no `Lti::Result` for this
submission
* check out this commit and repeat the above steps
* with this commit, the `Lti::Result` should have an accurate score,
user, and submitted_at timestamp
* manually grade the same student again, with a different score value
* the same Lti::Result
* test also on assignments created through AGS, both
  submission_type=none and submission_type=external_tool

Change-Id: I431159db38d960ab20a992250df652f3b8f559db
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/288127
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Xander Moffatt <xmoffatt@instructure.com>
QA-Review: Xander Moffatt <xmoffatt@instructure.com>
Product-Review: Evan Battaglia <ebattaglia@instructure.com>

app/models/submission.rb

@@ -2547,6 +2547,11 @@ class Submission < ActiveRecord::Base
     return unless saved_change_to_score?
     return if autograded? # Submission changed by LTI Tool, it will set result score directly
 
+    unless lti_result
+      assignment.line_items.first&.results&.create!(
+        submission: self, user: user, created_at: Time.zone.now, updated_at: Time.zone.now
+      )
+    end
     Lti::Result.update_score_for_submission(self, score)
   end
 

spec/factories/lti_result_factory.rb

@@ -26,7 +26,21 @@ module Factories
     )
     user = line_item_user(li_result_overrides, course)
     li = lti_result_line_item(li_result_overrides, course)
-    Lti::Result.create!(line_item_results_params(li_result_overrides, user, li))
+    time = Time.zone.now
+    submission = lti_result_submission(li_result_overrides, user, li)
+    # If submissionscore was updated, a Lti::Result will already exist
+    li = Lti::Result.find_or_initialize_by(line_item: li, submission: submission, user: user)
+    li.assign_attributes(
+      activity_progress: li_result_overrides.fetch(:activity_progress, "Completed"),
+      grading_progress: li_result_overrides.fetch(:grading_progress, "FullyGraded"),
+      result_score: li_result_overrides[:result_score],
+      result_maximum: li_result_overrides[:result_maximum],
+      updated_at: li_result_overrides.fetch(:updated_at, time),
+      created_at: time,
+      comment: li_result_overrides[:comment]
+    )
+    li.save!
+    li
   end
 
   private
@@ -70,21 +84,4 @@ module Factories
     submission.update(score: li_result_overrides[:result_score]) if li_result_overrides[:result_score]
     submission
   end
-
-  def line_item_results_params(li_result_overrides, user, li)
-    time = Time.zone.now
-    submission = lti_result_submission(li_result_overrides, user, li)
-    {
-      activity_progress: li_result_overrides.fetch(:activity_progress, "Completed"),
-      grading_progress: li_result_overrides.fetch(:grading_progress, "FullyGraded"),
-      line_item: li,
-      user: user,
-      submission: submission,
-      result_score: li_result_overrides[:result_score],
-      result_maximum: li_result_overrides[:result_maximum],
-      updated_at: li_result_overrides.fetch(:updated_at, time),
-      created_at: time,
-      comment: li_result_overrides[:comment]
-    }
-  end
 end

spec/models/submission_spec.rb

@@ -7368,10 +7368,36 @@ describe Submission do
   end
 
   describe "#update_line_item_result" do
-    it "does nothing if lti_result does not exist" do
-      submission = submission_model assignment: @assignment
-      expect(submission).to receive(:update_line_item_result)
-      submission.save!
+    let(:submission) { submission_model(assignment: @assignment) }
+
+    context "when lti_result does not exist" do
+      it "does nothing when there is no line item" do
+        expect do
+          submission.update!(score: 1.3)
+        end.to_not change { submission.lti_result }.from(nil)
+      end
+
+      context "when there is a line item" do
+        before { line_item_model(assignment: @assignment) }
+
+        it "does nothing if score has not changed" do
+          expect do
+            submission.update!(body: "hello abc")
+          end.to_not change { submission.lti_result }.from(nil)
+        end
+
+        it "creates an the lti_result with the correct score_given if the score has changed" do
+          expect do
+            submission.update!(score: 1.3)
+          end.to change { submission.lti_result&.reload&.result_score }.from(nil).to(1.3)
+        end
+
+        it "does nothing if the lti_result was updated by a tool" do
+          expect do
+            submission.update!(score: 1.3, grader_id: -123)
+          end.to_not change { submission.lti_result }.from(nil)
+        end
+      end
     end
 
     context "with lti_result" do