replace rdiscount gem with redcarpet

refs CCI-391

Test Plan:
1. Jenkins passes

flag = none

Change-Id: Id4d70067959daae86835ce78a2b38a31940b31f1
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/242166
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: James Butters <jbutters@instructure.com>
Product-Review: Aaron Ogata <aogata@instructure.com>
QA-Review: Aaron Ogata <aogata@instructure.com>

Gemfile.d/app.rb

@@ -80,7 +80,7 @@ gem 'inst-jobs', '0.15.21'
 gem 'inst-jobs-autoscaling', '1.0.5'
   gem 'aws-sdk-autoscaling', '1.32.0', require: false
 gem 'inst-jobs-statsd', '1.4.0'
-gem 'json', '2.3.0'
+gem 'json', '2.3.1'
 gem 'json_schemer', '0.2.10'
 gem 'json-jwt', '1.11.0', require: false
 gem 'link_header', '0.0.8'
@@ -103,7 +103,6 @@ gem 'rack-test', '1.1.0'
 gem 'rake', '13.0.1'
 gem 'rails-observers', '0.1.5'
 gem 'ratom-nokogiri', '0.10.8', require: false
-gem 'rdiscount', '2.2.0.1', require: false
 gem 'redcarpet', '3.5.0', require: false
 gem 'retriable', '1.4.1'
 gem 'ritex', '1.0.1', require: false
@@ -153,7 +152,6 @@ path 'gems' do
   gem 'canvas_text_helper'
   gem 'canvas_time'
   gem 'canvas_unzip'
-  gem 'csv_diff'
   gem 'diigo'
   gem 'event_stream'
   gem 'google_drive'
@@ -171,3 +169,6 @@ path 'gems' do
   gem 'utf8_cleaner'
   gem 'workflow'
 end
+
+gem 'csv_diff', path: 'gems'
+  gem 'sqlite3', '1.4.2'

Gemfile.d/sqlite.rb

@@ -1,20 +0,0 @@
-#
-# Copyright (C) 2014 - 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/>.
-
-group :sqlite do
-  gem 'sqlite3', '1.4.2'
-end

Gemfile.d/test.rb

@@ -26,7 +26,7 @@ group :test do
   gem 'simplecov', '0.15.1', require: false
     gem 'docile', '1.1.5', require: false
   gem 'simplecov-rcov', '0.2.3', require: false
-  gem 'puma', '4.3.3'
+  gem 'puma', '4.3.3', require: false
 
   gem 'rspec', '3.9.0'
   gem 'rspec_around_all', '0.2.0'
@@ -45,7 +45,7 @@ group :test do
   gem 'once-ler', '0.1.4'
   gem 'sauce_whisk', '0.2.2'
 
-  gem 'selenium-webdriver', '3.142.7'
+  gem 'selenium-webdriver', '3.142.7', require: false
     gem 'childprocess', '3.0.0', require: false
   gem 'webdrivers', '4.2.0', require: false
   gem 'test-queue', github: 'instructure/test-queue', ref: 'd35166408df3a5396cd809e85dcba175136a69ba', require: false
@@ -58,7 +58,7 @@ group :test do
   gem 'headless', '2.3.1', require: false
   gem 'escape_code', '0.2', require: false
   gem 'luminosity_contrast', '0.2.1'
-  gem 'pact', '1.49.0'
+  gem 'pact', '1.49.0', require: false
     gem 'pact-mock_service', '3.5.0', require: false
   gem 'pact-messages', '0.2.0'
   gem 'pact_broker-client', '1.25.0'

lib/text_helper.rb

@@ -1,4 +1,3 @@
-# encoding: UTF-8
 #
 # Copyright (C) 2011 - present Instructure, Inc.
 #
@@ -17,7 +16,7 @@
 # with this program. If not, see <http://www.gnu.org/licenses/>.
 
 require 'nokogiri'
-require 'rdiscount'
+require 'redcarpet'
 
 module TextHelper
   def force_zone(time)
@@ -239,7 +238,7 @@ module TextHelper
 
   def markdown(string, inlinify = :auto)
     string = ERB::Util.h(string) unless string.html_safe?
-    result = RDiscount.new(string).to_html.strip
+    result = Redcarpet::Markdown.new(Redcarpet::Render::XHTML.new).render(string).strip
     # Strip wrapping <p></p> if inlinify == :auto && they completely wrap the result && there are not multiple <p>'s
     result.gsub!(/<\/?p>/, '') if inlinify == :auto && result =~ /\A<p>.*<\/p>\z/m && !(result =~ /.*<p>.*<p>.*/m)
     result.strip.html_safe

spec/lib/text_helper_spec.rb

@@ -158,7 +158,7 @@ describe TextHelper do
       it "should not escape MarkdownSafeBuffers" do
         expect(th.mt(:foo, "We **do** trust the following input: %{input}", :input => th.markdown_safe("`a` **b** _c_ ![d](e)\n# f\n + g\n - h"))).
           to eq <<-HTML.strip
-<p>We <strong>do</strong> trust the following input: <code>a</code> <strong>b</strong> <em>c</em> <img src="e" alt="d" /></p>
+<p>We <strong>do</strong> trust the following input: <code>a</code> <strong>b</strong> <em>c</em> <img src="e" alt="d"/></p>
 
 <h1>f</h1>