allow teachers to set lti submission type when grading

Refs PFS-4941

Test plan:
- Create an assignment in a course with an active student
- As a teacher, use submissions update endpoint to assign
    a submission type of 'basic_lti_launch' and url to student
- Verify submission has been updated with correct submission type and url
- Create another assignment with any online submission types
- As a student, submit to the assignment
- As a teacher, use the submissions update endpoint to attempt to
    assign a submission type of 'basic_lti_launch' and url
    for student
- Verify submission type used by student remains, and changes
    attempted by teacher were not applied

Change-Id: I2bd7f3345df06135cd0328fc87826563b2481bad
Reviewed-on: https://gerrit.instructure.com/86183
Tested-by: Jenkins
Reviewed-by: Keith T. Garner <kgarner@instructure.com>
Reviewed-by: Neil Gupta <ngupta@instructure.com>
QA-Review: Amber Taniuchi <amber@instructure.com>
Product-Review: Christi Wruck

app/controllers/submissions_api_controller.rb

@@ -599,6 +599,10 @@ class SubmissionsApiController < ApplicationController
         submission[:excuse] = params[:submission].delete(:excuse)
         submission[:provisional] = value_to_boolean(params[:submission][:provisional])
         submission[:final] = value_to_boolean(params[:submission][:final]) && @context.grants_right?(@current_user, :moderate_grades)
+        if params[:submission][:submission_type] == 'basic_lti_launch' && (!@submission.has_submission? || @submission.submission_type == 'basic_lti_launch')
+          submission[:submission_type] = params[:submission][:submission_type]
+          submission[:url] = params[:submission][:url]
+        end
       end
       if submission[:grade] || submission[:excuse]
         begin

spec/apis/v1/submissions_api_spec.rb

@@ -2161,6 +2161,57 @@ describe 'Submissions API', type: :request do
             { expected_status: 400 })
       expect(json["error"]).not_to be_nil
     end
+
+    it "allows a LTI launch URL to be assigned" do
+      json = api_call(
+        :put,
+        "/api/v1/courses/#{@course.id}/assignments/#{@assignment.id}/submissions/#{@student.id}.json",
+        {
+          controller: 'submissions_api',
+          action: 'update',
+          format: 'json',
+          course_id: @course.id.to_s,
+          assignment_id: @assignment.id.to_s,
+          user_id: @student.id.to_s
+        }, {
+          submission: {
+            posted_grade: 'B',
+            submission_type: 'basic_lti_launch',
+            url: 'http://example.test'
+          },
+        }
+      )
+
+      expect(Submission.count).to eq 1
+      expect(json['submission_type']).to eql 'basic_lti_launch'
+      expect(json['url']).to eql 'http://example.test'
+    end
+
+    it 'does not allow a submission to be overwritten if type is a non-lti type' do
+      submission = @assignment.submit_homework(@student, body: 'what')
+      json = api_call(
+        :put,
+        "/api/v1/courses/#{@course.id}/assignments/#{@assignment.id}/submissions/#{@student.id}.json",
+        {
+          controller: 'submissions_api',
+          action: 'update',
+          format: 'json',
+          course_id: @course.id.to_s,
+          assignment_id: @assignment.id.to_s,
+          user_id: @student.id.to_s
+        }, {
+          submission: {
+            posted_grade: 'B',
+            submission_type: 'basic_lti_launch',
+            url: 'http://example.test'
+          },
+        }
+      )
+
+      expect(Submission.count).to eq 1
+      expect(json['submission_type']).to eql 'online_text_entry'
+      expect(json['url']).to be_nil
+    end
   end
 
   it "should allow posting grade by sis id" do