change resource link lookup_uuid uniqueness constraint

We're changing the uniquess constraint of lookup_uuid in favor a multiple
columns uniqueness constraint scoped to the context (context_id and
context_type).

refs INTEROP-6502
flag=none

test-plan
* specs should pass?

Change-Id: If2408b6677dd04439d8ef544ec6c864a212d90c1
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/258632
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
QA-Review: Wagner Goncalves <wagner.goncalves@instructure.com>
Product-Review: Wagner Goncalves <wagner.goncalves@instructure.com>
Reviewed-by: Xander Moffatt <xmoffatt@instructure.com>
Reviewed-by: Ethan Vizitei <evizitei@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>

app/models/lti/resource_link.rb

@@ -25,7 +25,7 @@ class Lti::ResourceLink < ApplicationRecord
 
   validates :context_external_tool_id, :context_id, :context_type, :lookup_uuid,
             :resource_link_uuid, presence: true
-  validates :lookup_uuid, uniqueness: true
+  validates :lookup_uuid, uniqueness: { scope: [:context_id, :context_type] }
 
   belongs_to :context_external_tool
   belongs_to :context, polymorphic: [:account, :assignment, :course]

db/migrate/20210209193828_change_lookup_uuid_index_at_lti_resource_links.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+# Copyright (C) 2021 - 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 ChangeLookupUuidIndexAtLtiResourceLinks < ActiveRecord::Migration[5.2]
+  tag :predeploy
+
+  disable_ddl_transaction!
+
+  def change
+    add_index :lti_resource_links, [:lookup_uuid, :context_id, :context_type],
+              algorithm: :concurrently, if_not_exists: true, unique: true,
+              name: "index_lti_resource_links_unique_lookup_uuid_on_context"
+
+    remove_index :lti_resource_links, column: :lookup_uuid, if_exists: true
+  end
+end

spec/models/lti/resource_link_spec.rb

@@ -56,8 +56,8 @@ RSpec.describe Lti::ResourceLink, type: :model do
       expect(resource_link.original_context_external_tool).to eq tool
     end
 
-    it '`lookup_uuid` should be unique' do
-      expect(resource_link).to validate_uniqueness_of(:lookup_uuid).ignoring_case_sensitivity
+    it '`lookup_uuid` should be unique scoped to `context`' do
+      expect(resource_link).to validate_uniqueness_of(:lookup_uuid).scoped_to(:context_id, :context_type).ignoring_case_sensitivity
     end
   end