# HG changeset patch
# User Nattee Niparnan <nattee@gmail.com>
# Date 2022-01-24 11:10:22
# Node ID feb677289536c5c45d3e6aa0dee4495cb92608b7
# Parent  e2597379728cebc53a172ac9ecd5ca874ee05742
# Parent  6dcbc91b8f6295abd1c485999dabad52bf82a221

merge with rails7 branch

diff --git a/.ruby-version b/.ruby-version
--- a/.ruby-version
+++ b/.ruby-version
@@ -1,1 +1,1 @@
-ruby-2.6.3
+ruby-3.1.0
diff --git a/Gemfile b/Gemfile
--- a/Gemfile
+++ b/Gemfile
@@ -1,13 +1,19 @@
 source 'https://rubygems.org'
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
+ruby '3.1.0'
+
 #rails
-gem 'rails', '~>5.2'
+gem 'rails', '~>7.0'
+
+# The original asset pipeline for Rails [https://github.com/rails/sprockets-rails]
+gem "sprockets-rails"
+
 gem 'activerecord-session_store'
 gem 'puma'
 
 # Reduces boot times through caching; required in config/boot.rb
-gem 'bootsnap', '>= 1.1.0', require: false
+gem 'bootsnap', require: false
 
 # Bundle edge Rails instead:
 # gem 'rails', :git => 'git://github.com/rails/rails.git'
@@ -41,11 +47,11 @@
 # Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
 #gem 'turbolinks', '~> 5'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
-gem 'jbuilder', '~> 2.5'
+gem 'jbuilder'
 
 
 #in-place editor
-gem 'best_in_place', '~> 3.0.1'
+gem 'best_in_place', git: "https://github.com/mmotherwell/best_in_place"
 
 # jquery addition
 gem 'jquery-rails'
@@ -93,7 +99,7 @@
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
-  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
+  gem 'debug', platforms: [:mri, :mingw, :x64_mingw]
 end
 
 group :development do
@@ -103,14 +109,15 @@
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
   gem 'spring'
   gem 'spring-watcher-listen', '~> 2.0.0'
+
+  # Add speed badges [https://github.com/MiniProfiler/rack-mini-profiler]
+  # gem "rack-mini-profiler"
 end
 
 group :test do
   # Adds support for Capybara system testing and selenium driver
-  gem 'capybara', '>= 2.15'
+  gem 'capybara'
   gem 'selenium-webdriver'
-  # Easy installation and use of chromedriver to run system tests with Chrome
-  #gem 'chromedriver-helper'
-  gem 'webdriver'
+  gem 'webdrivers'
 end
 
diff --git a/Gemfile.lock b/Gemfile.lock
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,211 +1,265 @@
+GIT
+  remote: https://github.com/mmotherwell/best_in_place
+  revision: 88eb3052623a9a6cd346864d2aca05021c2f80d0
+  specs:
+    best_in_place (3.1.1)
+      actionpack (>= 3.2)
+      railties (>= 3.2)
+
 GEM
   remote: https://rubygems.org/
   specs:
-    RubyInline (3.12.4)
+    RubyInline (3.12.5)
       ZenTest (~> 4.3)
-    ZenTest (4.11.2)
-    ace-rails-ap (4.2)
-    actioncable (5.2.4.2)
-      actionpack (= 5.2.4.2)
+    ZenTest (4.12.0)
+    ace-rails-ap (4.4)
+    actioncable (7.0.1)
+      actionpack (= 7.0.1)
+      activesupport (= 7.0.1)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
-    actionmailer (5.2.4.2)
-      actionpack (= 5.2.4.2)
-      actionview (= 5.2.4.2)
-      activejob (= 5.2.4.2)
+    actionmailbox (7.0.1)
+      actionpack (= 7.0.1)
+      activejob (= 7.0.1)
+      activerecord (= 7.0.1)
+      activestorage (= 7.0.1)
+      activesupport (= 7.0.1)
+      mail (>= 2.7.1)
+      net-imap
+      net-pop
+      net-smtp
+    actionmailer (7.0.1)
+      actionpack (= 7.0.1)
+      actionview (= 7.0.1)
+      activejob (= 7.0.1)
+      activesupport (= 7.0.1)
       mail (~> 2.5, >= 2.5.4)
+      net-imap
+      net-pop
+      net-smtp
       rails-dom-testing (~> 2.0)
-    actionpack (5.2.4.2)
-      actionview (= 5.2.4.2)
-      activesupport (= 5.2.4.2)
-      rack (~> 2.0, >= 2.0.8)
+    actionpack (7.0.1)
+      actionview (= 7.0.1)
+      activesupport (= 7.0.1)
+      rack (~> 2.0, >= 2.2.0)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.2.4.2)
-      activesupport (= 5.2.4.2)
+      rails-html-sanitizer (~> 1.0, >= 1.2.0)
+    actiontext (7.0.1)
+      actionpack (= 7.0.1)
+      activerecord (= 7.0.1)
+      activestorage (= 7.0.1)
+      activesupport (= 7.0.1)
+      globalid (>= 0.6.0)
+      nokogiri (>= 1.8.5)
+    actionview (7.0.1)
+      activesupport (= 7.0.1)
       builder (~> 3.1)
       erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (5.2.4.2)
-      activesupport (= 5.2.4.2)
+      rails-html-sanitizer (~> 1.1, >= 1.2.0)
+    activejob (7.0.1)
+      activesupport (= 7.0.1)
       globalid (>= 0.3.6)
-    activemodel (5.2.4.2)
-      activesupport (= 5.2.4.2)
-    activerecord (5.2.4.2)
-      activemodel (= 5.2.4.2)
-      activesupport (= 5.2.4.2)
-      arel (>= 9.0)
-    activerecord-session_store (1.1.3)
-      actionpack (>= 4.0)
-      activerecord (>= 4.0)
+    activemodel (7.0.1)
+      activesupport (= 7.0.1)
+    activerecord (7.0.1)
+      activemodel (= 7.0.1)
+      activesupport (= 7.0.1)
+    activerecord-session_store (2.0.0)
+      actionpack (>= 5.2.4.1)
+      activerecord (>= 5.2.4.1)
       multi_json (~> 1.11, >= 1.11.2)
-      rack (>= 1.5.2, < 3)
-      railties (>= 4.0)
-    activestorage (5.2.4.2)
-      actionpack (= 5.2.4.2)
-      activerecord (= 5.2.4.2)
-      marcel (~> 0.3.1)
-    activesupport (5.2.4.2)
+      rack (>= 2.0.8, < 3)
+      railties (>= 5.2.4.1)
+    activestorage (7.0.1)
+      actionpack (= 7.0.1)
+      activejob (= 7.0.1)
+      activerecord (= 7.0.1)
+      activesupport (= 7.0.1)
+      marcel (~> 1.0)
+      mini_mime (>= 1.1.0)
+    activesupport (7.0.1)
       concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 0.7, < 2)
-      minitest (~> 5.1)
-      tzinfo (~> 1.1)
-    addressable (2.7.0)
+      i18n (>= 1.6, < 2)
+      minitest (>= 5.1)
+      tzinfo (~> 2.0)
+    addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
     ansi (1.5.0)
-    arel (9.0.0)
-    autoprefixer-rails (9.5.1)
-      execjs
-    best_in_place (3.0.3)
-      actionpack (>= 3.2)
-      railties (>= 3.2)
+    autoprefixer-rails (10.4.2.0)
+      execjs (~> 2)
     bindex (0.8.1)
-    bootsnap (1.4.6)
+    bootsnap (1.9.4)
       msgpack (~> 1.0)
     bootstrap-sass (3.4.1)
       autoprefixer-rails (>= 5.2.1)
       sassc (>= 2.0.0)
-    bootstrap-switch-rails (3.3.4)
+    bootstrap-switch-rails (3.3.5)
     bootstrap-toggle-rails (2.2.1.0)
     bootstrap3-datetimepicker-rails (4.17.47)
       momentjs-rails (>= 2.8.1)
     builder (3.2.4)
-    byebug (11.0.1)
-    capybara (3.15.1)
+    capybara (3.36.0)
       addressable
+      matrix
       mini_mime (>= 0.1.3)
       nokogiri (~> 1.8)
       rack (>= 1.6.0)
       rack-test (>= 0.6.3)
-      regexp_parser (~> 1.2)
+      regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
-    childprocess (3.0.0)
-    coffee-rails (4.2.2)
+    childprocess (4.1.0)
+    coffee-rails (5.0.0)
       coffee-script (>= 2.2.0)
-      railties (>= 4.0.0)
+      railties (>= 5.2.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.1.6)
+    concurrent-ruby (1.1.9)
     crass (1.0.6)
+    debug (1.4.0)
+      irb (>= 1.3.6)
+      reline (>= 0.2.7)
+    digest (3.1.0)
     dynamic_form (1.1.4)
-    erubi (1.9.0)
+    erubi (1.10.0)
     erubis (2.7.0)
-    execjs (2.7.0)
-    ffi (1.10.0)
+    execjs (2.8.1)
+    ffi (1.15.5)
     fuzzy-string-match (1.0.1)
       RubyInline (>= 3.8.6)
-    globalid (0.4.2)
-      activesupport (>= 4.2.0)
-    haml (5.0.4)
+    globalid (1.0.0)
+      activesupport (>= 5.0)
+    haml (5.2.2)
       temple (>= 0.8.0)
       tilt
-    haml-rails (1.0.0)
-      actionpack (>= 4.0.1)
-      activesupport (>= 4.0.1)
+    haml-rails (2.0.1)
+      actionpack (>= 5.1)
+      activesupport (>= 5.1)
       haml (>= 4.0.6, < 6.0)
       html2haml (>= 1.0.1)
-      railties (>= 4.0.1)
+      railties (>= 5.1)
     html2haml (2.2.0)
       erubis (~> 2.7.0)
       haml (>= 4.0, < 6)
       nokogiri (>= 1.6.0)
       ruby_parser (~> 3.5)
-    i18n (1.8.2)
+    i18n (1.8.11)
       concurrent-ruby (~> 1.0)
     in_place_editing (1.2.0)
-    jbuilder (2.10.0)
+    io-console (0.5.11)
+    io-wait (0.2.1)
+    irb (1.4.1)
+      reline (>= 0.3.0)
+    jbuilder (2.11.5)
+      actionview (>= 5.0.0)
       activesupport (>= 5.0.0)
     jquery-countdown-rails (2.0.2)
-    jquery-rails (4.3.3)
+    jquery-rails (4.4.0)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
-    jquery-tablesorter (1.26.1)
-      railties (>= 3.2, < 6)
+    jquery-tablesorter (1.27.2)
+      railties (>= 3.2)
     jquery-ui-rails (6.0.1)
       railties (>= 3.2.16)
-    listen (3.1.5)
+    listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-      ruby_dep (~> 1.2)
-    loofah (2.4.0)
+    loofah (2.13.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
-    marcel (0.3.3)
-      mimemagic (~> 0.3.2)
+    marcel (1.0.2)
+    matrix (0.4.2)
     method_source (1.0.0)
-    mimemagic (0.3.4)
-    mini_mime (1.0.2)
-    mini_portile2 (2.4.0)
-    minitest (5.14.0)
-    minitest-reporters (1.3.6)
+    mini_mime (1.1.2)
+    minitest (5.15.0)
+    minitest-reporters (1.5.0)
       ansi
       builder
       minitest (>= 5.0)
       ruby-progressbar
-    momentjs-rails (2.20.1)
+    momentjs-rails (2.29.1.1)
       railties (>= 3.1)
-    msgpack (1.3.3)
-    multi_json (1.13.1)
-    mysql2 (0.5.2)
-    nio4r (2.5.2)
-    nokogiri (1.10.9)
-      mini_portile2 (~> 2.4.0)
-    public_suffix (4.0.3)
-    puma (4.3.3)
+    msgpack (1.4.2)
+    multi_json (1.15.0)
+    mysql2 (0.5.3)
+    net-imap (0.2.3)
+      digest
+      net-protocol
+      strscan
+    net-pop (0.1.1)
+      digest
+      net-protocol
+      timeout
+    net-protocol (0.1.2)
+      io-wait
+      timeout
+    net-smtp (0.3.1)
+      digest
+      net-protocol
+      timeout
+    nio4r (2.5.8)
+    nokogiri (1.13.1-x86_64-linux)
+      racc (~> 1.4)
+    public_suffix (4.0.6)
+    puma (5.5.2)
       nio4r (~> 2.0)
-    rack (2.2.2)
+    racc (1.6.0)
+    rack (2.2.3)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
-    rails (5.2.4.2)
-      actioncable (= 5.2.4.2)
-      actionmailer (= 5.2.4.2)
-      actionpack (= 5.2.4.2)
-      actionview (= 5.2.4.2)
-      activejob (= 5.2.4.2)
-      activemodel (= 5.2.4.2)
-      activerecord (= 5.2.4.2)
-      activestorage (= 5.2.4.2)
-      activesupport (= 5.2.4.2)
-      bundler (>= 1.3.0)
-      railties (= 5.2.4.2)
-      sprockets-rails (>= 2.0.0)
-    rails-controller-testing (1.0.4)
-      actionpack (>= 5.0.1.x)
-      actionview (>= 5.0.1.x)
-      activesupport (>= 5.0.1.x)
+    rails (7.0.1)
+      actioncable (= 7.0.1)
+      actionmailbox (= 7.0.1)
+      actionmailer (= 7.0.1)
+      actionpack (= 7.0.1)
+      actiontext (= 7.0.1)
+      actionview (= 7.0.1)
+      activejob (= 7.0.1)
+      activemodel (= 7.0.1)
+      activerecord (= 7.0.1)
+      activestorage (= 7.0.1)
+      activesupport (= 7.0.1)
+      bundler (>= 1.15.0)
+      railties (= 7.0.1)
+    rails-controller-testing (1.0.5)
+      actionpack (>= 5.0.1.rc1)
+      actionview (>= 5.0.1.rc1)
+      activesupport (>= 5.0.1.rc1)
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.3.0)
+    rails-html-sanitizer (1.4.2)
       loofah (~> 2.3)
-    rails_bootstrap_sortable (2.0.6)
+    rails_bootstrap_sortable (2.0.7)
       momentjs-rails (>= 2.8.3)
-    railties (5.2.4.2)
-      actionpack (= 5.2.4.2)
-      activesupport (= 5.2.4.2)
+    railties (7.0.1)
+      actionpack (= 7.0.1)
+      activesupport (= 7.0.1)
       method_source
-      rake (>= 0.8.7)
-      thor (>= 0.19.0, < 2.0)
-    rake (13.0.1)
-    rb-fsevent (0.10.3)
-    rb-inotify (0.10.0)
+      rake (>= 12.2)
+      thor (~> 1.0)
+      zeitwerk (~> 2.5)
+    rake (13.0.6)
+    rb-fsevent (0.11.0)
+    rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rdiscount (2.2.0.1)
-    regexp_parser (1.7.0)
-    rouge (3.3.0)
-    ruby-progressbar (1.10.0)
-    ruby_dep (1.5.0)
-    ruby_parser (3.13.1)
-      sexp_processor (~> 4.9)
-    rubyzip (1.3.0)
-    sassc (2.2.1)
+    rdiscount (2.2.0.2)
+    regexp_parser (2.2.0)
+    reline (0.3.1)
+      io-console (~> 0.5)
+    rexml (3.2.5)
+    rouge (3.27.0)
+    ruby-progressbar (1.11.0)
+    ruby_parser (3.18.1)
+      sexp_processor (~> 4.16)
+    rubyzip (2.3.2)
+    sassc (2.4.0)
       ffi (~> 1.9)
     sassc-rails (2.1.2)
       railties (>= 4.0.0)
@@ -213,73 +267,77 @@
       sprockets (> 3.0)
       sprockets-rails
       tilt
-    select2-rails (4.0.3)
-      thor (~> 0.14)
-    selenium-webdriver (3.142.7)
-      childprocess (>= 0.5, < 4.0)
+    select2-rails (4.0.13)
+    selenium-webdriver (4.1.0)
+      childprocess (>= 0.5, < 5.0)
+      rexml (~> 3.2, >= 3.2.5)
       rubyzip (>= 1.2.2)
-    sexp_processor (4.12.0)
-    simple_form (5.0.2)
-      actionpack (>= 5.0)
-      activemodel (>= 5.0)
-    spring (2.0.2)
-      activesupport (>= 4.2)
+    sexp_processor (4.16.0)
+    simple_form (5.1.0)
+      actionpack (>= 5.2)
+      activemodel (>= 5.2)
+    spring (2.1.1)
     spring-watcher-listen (2.0.1)
       listen (>= 2.7, < 4.0)
       spring (>= 1.2, < 3.0)
-    sprockets (3.7.2)
+    sprockets (4.0.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.1)
-      actionpack (>= 4.0)
-      activesupport (>= 4.0)
+    sprockets-rails (3.4.2)
+      actionpack (>= 5.2)
+      activesupport (>= 5.2)
       sprockets (>= 3.0.0)
-    sqlite3 (1.4.1)
-    temple (0.8.1)
-    thor (0.20.3)
-    thread_safe (0.3.6)
-    tilt (2.0.9)
-    tzinfo (1.2.7)
-      thread_safe (~> 0.1)
-    uglifier (4.1.20)
+    sqlite3 (1.4.2)
+    strscan (3.0.1)
+    temple (0.8.2)
+    thor (1.2.1)
+    tilt (2.0.10)
+    timeout (0.2.0)
+    tzinfo (2.0.4)
+      concurrent-ruby (~> 1.0)
+    uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
-    web-console (3.7.0)
-      actionview (>= 5.0)
-      activemodel (>= 5.0)
+    web-console (4.2.0)
+      actionview (>= 6.0.0)
+      activemodel (>= 6.0.0)
       bindex (>= 0.4.0)
-      railties (>= 5.0)
-    webdriver (0.5.0)
-    websocket-driver (0.7.1)
+      railties (>= 6.0.0)
+    webdrivers (5.0.0)
+      nokogiri (~> 1.6)
+      rubyzip (>= 1.3.0)
+      selenium-webdriver (~> 4.0)
+    websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.4)
+    websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
     yaml_db (0.7.0)
       rails (>= 3.0)
       rake (>= 0.8.7)
+    zeitwerk (2.5.3)
 
 PLATFORMS
-  ruby
+  x86_64-linux
 
 DEPENDENCIES
   ace-rails-ap
   activerecord-session_store
   autoprefixer-rails
-  best_in_place (~> 3.0.1)
-  bootsnap (>= 1.1.0)
+  best_in_place!
+  bootsnap
   bootstrap-sass (~> 3.4.1)
   bootstrap-switch-rails
   bootstrap-toggle-rails
   bootstrap3-datetimepicker-rails (~> 4.17.47)
-  byebug
-  capybara (>= 2.15)
+  capybara
   coffee-rails
+  debug
   dynamic_form
   fuzzy-string-match
   haml
   haml-rails
   in_place_editing
-  jbuilder (~> 2.5)
+  jbuilder
   jquery-countdown-rails
   jquery-rails
   jquery-tablesorter
@@ -290,7 +348,7 @@
   momentjs-rails (>= 2.9.0)
   mysql2
   puma
-  rails (~> 5.2)
+  rails (~> 7.0)
   rails-controller-testing
   rails_bootstrap_sortable
   rdiscount
@@ -301,11 +359,15 @@
   simple_form
   spring
   spring-watcher-listen (~> 2.0.0)
+  sprockets-rails
   sqlite3
   uglifier
   web-console (>= 3.3.0)
-  webdriver
+  webdrivers
   yaml_db
 
+RUBY VERSION
+   ruby 3.1.0p0
+
 BUNDLED WITH
-   1.17.2
+   2.3.3
diff --git a/README.rdoc b/README.rdoc
--- a/README.rdoc
+++ b/README.rdoc
@@ -45,13 +45,27 @@
     cafe@grader:~$ sudo apt-get update
     cafe@grader:~$ sudo apt-get install rvm
 
-This is very important. You have to logout and login again since RVM change a lots of system. 
+We also need to add our user to the rvm group
+
+    sudo usermod -a -G rvm $USER
 
-If you are using GUI version of Ubuntu, be sure to have Gnome Terminal (or any other terminal you are using) perform login every time. This can be done by mark the check box "Run command as a login shell" in Gnome terminal or by adding --login to bash. 
+This is very important. 
+1. You have to reboot since RVM change a lots of system.
+2. If you are using GUI version of Ubuntu, be sure to have Gnome Terminal (or any other terminal you are using) perform login every time. This can be done by mark the check box "Run command as a login shell" in Gnome terminal or by adding --login to bash. 
+
+=== 3. Install necessary package and nodejs
 
-=== 3. Install necessary package
+First, we install required package via apt.
+
+    cafe@grader:~$ sudo apt install libmysqlclient-dev default-jdk unzip php-cli apache2 dirmngr gnupg apache2-dev
+
+Since nodejs that comes with ubuntu 18.04 is very outdated, we need to install it manually. This follow the method outlined in https://www.digitalocean.com/community/tutorials/how-to-install-node-js-on-ubuntu-18-04 under *Installing Node.js with Apt Using a NodeSource PPA*
 
-    cafe@grader:~$ sudo apt install libmysqlclient-dev default-jdk unzip nodejs php-cli apache2 dirmngr gnupg apache2-dev
+    cd ~
+    curl -sL https://deb.nodesource.com/setup_17.x -o nodesource_setup.sh
+    sudo bash nodesource_setup.sh
+    sudo apt install nodejs
+
 
 === 4. Install cafe-grader
 
diff --git a/app/assets/config/manifest.js b/app/assets/config/manifest.js
new file mode 100644
--- /dev/null
+++ b/app/assets/config/manifest.js
@@ -0,0 +1,4 @@
+//= link_tree ../images
+//= link_directory ../javascripts .js
+//= link_directory ../stylesheets .css
+
diff --git a/app/assets/stylesheets/graders.css b/app/assets/stylesheets/graders.css
deleted file mode 100644
--- a/app/assets/stylesheets/graders.css
+++ /dev/null
@@ -1,17 +0,0 @@
-
-table.graders tr.active {
-    border: 1px solid black;
-    background: lightgreen;
-    text-align: center;
-}
-
-table.graders tr.inactive {
-    border: 1px solid black;
-    background: #ffcccc;
-    text-align: center;
-}
-
-.submitbox .item {
-    padding-right: 5px;
-    float: left;
-}
diff --git a/app/assets/stylesheets/graders.css.scss b/app/assets/stylesheets/graders.css.scss
--- a/app/assets/stylesheets/graders.css.scss
+++ b/app/assets/stylesheets/graders.css.scss
@@ -0,0 +1,18 @@
+table.graders tr {
+  &.active {
+    border: 1px solid black;
+    background: lightgreen;
+    text-align: center;
+  }
+
+  &.inactive {
+    border: 1px solid black;
+    background: #ffcccc;
+    text-align: center;
+  }
+}
+
+.submitbox .item {
+  padding-right: 5px;
+  float: left;
+}
diff --git a/app/assets/stylesheets/problems.css b/app/assets/stylesheets/problems.css
deleted file mode 100644
--- a/app/assets/stylesheets/problems.css
+++ /dev/null
@@ -1,14 +0,0 @@
-
-tr.available {
-    background: #c0ffc0;
-}
-
-tr.not-available {
-    background: #ffc0c0;
-}
-
-.import-log {
-    background: lightgray;
-    border: solid black 1px;
-    padding: 10px;
-}
\ No newline at end of file
diff --git a/app/assets/stylesheets/problems.css.scss b/app/assets/stylesheets/problems.css.scss
--- a/app/assets/stylesheets/problems.css.scss
+++ b/app/assets/stylesheets/problems.css.scss
@@ -0,0 +1,15 @@
+tr {
+  &.available {
+    background: #c0ffc0;
+  }
+
+  &.not-available {
+    background: #ffc0c0;
+  }
+}
+
+.import-log {
+  background: lightgray;
+  border: solid black 1px;
+  padding: 10px;
+}
diff --git a/bin/rails b/bin/rails
--- a/bin/rails
+++ b/bin/rails
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
-APP_PATH = File.expand_path('../config/application', __dir__)
-require_relative '../config/boot'
-require 'rails/commands'
+APP_PATH = File.expand_path("../config/application", __dir__)
+require_relative "../config/boot"
+require "rails/commands"
diff --git a/bin/rake b/bin/rake
--- a/bin/rake
+++ b/bin/rake
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby
-require_relative '../config/boot'
-require 'rake'
+require_relative "../config/boot"
+require "rake"
 Rake.application.run
diff --git a/bin/setup b/bin/setup
--- a/bin/setup
+++ b/bin/setup
@@ -1,36 +1,33 @@
 #!/usr/bin/env ruby
-require 'fileutils'
-include FileUtils
+require "fileutils"
 
 # path to your application root.
-APP_ROOT = File.expand_path('..', __dir__)
+APP_ROOT = File.expand_path("..", __dir__)
 
 def system!(*args)
   system(*args) || abort("\n== Command #{args} failed ==")
 end
 
-chdir APP_ROOT do
-  # This script is a starting point to setup your application.
+FileUtils.chdir APP_ROOT do
+  # This script is a way to set up or update your development environment automatically.
+  # This script is idempotent, so that you can run it at any time and get an expectable outcome.
   # Add necessary setup steps to this file.
 
-  puts '== Installing dependencies =='
-  system! 'gem install bundler --conservative'
-  system('bundle check') || system!('bundle install')
-
-  # Install JavaScript dependencies if using Yarn
-  # system('bin/yarn')
+  puts "== Installing dependencies =="
+  system! "gem install bundler --conservative"
+  system("bundle check") || system!("bundle install")
 
   # puts "\n== Copying sample files =="
-  # unless File.exist?('config/database.yml')
-  #   cp 'config/database.yml.sample', 'config/database.yml'
+  # unless File.exist?("config/database.yml")
+  #   FileUtils.cp "config/database.yml.sample", "config/database.yml"
   # end
 
   puts "\n== Preparing database =="
-  system! 'bin/rails db:setup'
+  system! "bin/rails db:prepare"
 
   puts "\n== Removing old logs and tempfiles =="
-  system! 'bin/rails log:clear tmp:clear'
+  system! "bin/rails log:clear tmp:clear"
 
   puts "\n== Restarting application server =="
-  system! 'bin/rails restart'
+  system! "bin/rails restart"
 end
diff --git a/bin/spring b/bin/spring
new file mode 100755
--- /dev/null
+++ b/bin/spring
@@ -0,0 +1,14 @@
+#!/usr/bin/env ruby
+if !defined?(Spring) && [nil, "development", "test"].include?(ENV["RAILS_ENV"])
+  gem "bundler"
+  require "bundler"
+
+  # Load Spring without loading other gems in the Gemfile, for speed.
+  Bundler.locked_gems&.specs&.find { |spec| spec.name == "spring" }&.tap do |spring|
+    Gem.use_paths Gem.dir, Bundler.bundle_path.to_s, *Gem.path
+    gem "spring", spring.version
+    require "spring/binstub"
+  rescue Gem::LoadError
+    # Ignore when Spring is not installed.
+  end
+end
diff --git a/bin/yarn b/bin/yarn
--- a/bin/yarn
+++ b/bin/yarn
@@ -1,9 +1,15 @@
 #!/usr/bin/env ruby
 APP_ROOT = File.expand_path('..', __dir__)
 Dir.chdir(APP_ROOT) do
-  begin
-    exec "yarnpkg", *ARGV
-  rescue Errno::ENOENT
+  yarn = ENV["PATH"].split(File::PATH_SEPARATOR).
+    select { |dir| File.expand_path(dir) != __dir__ }.
+    product(["yarn", "yarn.cmd", "yarn.ps1"]).
+    map { |dir, file| File.expand_path(file, dir) }.
+    find { |file| File.executable?(file) }
+
+  if yarn
+    exec yarn, *ARGV
+  else
     $stderr.puts "Yarn executable was not detected in the system."
     $stderr.puts "Download Yarn at https://yarnpkg.com/en/docs/install"
     exit 1
diff --git a/config.ru b/config.ru
--- a/config.ru
+++ b/config.ru
@@ -1,4 +1,6 @@
 # This file is used by Rack-based servers to start the application.
 
-require ::File.expand_path('../config/environment',  __FILE__)
-run CafeGrader::Application
+require_relative "config/environment"
+
+run Rails.application
+Rails.application.load_server
diff --git a/config/boot.rb b/config/boot.rb
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,4 +1,4 @@
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
 
-require 'bundler/setup' # Set up gems listed in the Gemfile.
-require 'bootsnap/setup' # Speed up boot time by caching expensive operations.
+require "bundler/setup" # Set up gems listed in the Gemfile.
+require "bootsnap/setup" # Speed up boot time by caching expensive operations.
diff --git a/config/cable.yml b/config/cable.yml
--- a/config/cable.yml
+++ b/config/cable.yml
@@ -2,7 +2,7 @@
   adapter: async
 
 test:
-  adapter: async
+  adapter: test
 
 production:
   adapter: redis
diff --git a/config/environment.rb b/config/environment.rb
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -1,5 +1,5 @@
 # Load the Rails application.
-require_relative 'application'
+require_relative "application"
 
 # Initialize the Rails application.
 Rails.application.initialize!
diff --git a/config/environments/development.rb b/config/environments/development.rb
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -1,8 +1,10 @@
+require "active_support/core_ext/integer/time"
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
-  # In the development environment your application's code is reloaded on
-  # every request. This slows down response time but is perfect for development
+  # In the development environment your application's code is reloaded any time
+  # it changes. This slows down response time but is perfect for development
   # since you don't have to restart the web server when you make code changes.
   config.cache_classes = false
 
@@ -12,14 +14,18 @@
   # Show full error reports.
   config.consider_all_requests_local = true
 
+  # Enable server timing
+  config.server_timing = true
+
   # Enable/disable caching. By default caching is disabled.
   # Run rails dev:cache to toggle caching.
-  if Rails.root.join('tmp', 'caching-dev.txt').exist?
+  if Rails.root.join("tmp/caching-dev.txt").exist?
     config.action_controller.perform_caching = true
+    config.action_controller.enable_fragment_cache_logging = true
 
     config.cache_store = :memory_store
     config.public_file_server.headers = {
-      'Cache-Control' => "public, max-age=#{2.days.to_i}"
+      "Cache-Control" => "public, max-age=#{2.days.to_i}"
     }
   else
     config.action_controller.perform_caching = false
@@ -27,7 +33,7 @@
     config.cache_store = :null_store
   end
 
-  # Store uploaded files on the local file system (see config/storage.yml for options)
+  # Store uploaded files on the local file system (see config/storage.yml for options).
   config.active_storage.service = :local
 
   # Don't care if the mailer can't send.
@@ -38,6 +44,12 @@
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
+  # Raise exceptions for disallowed deprecations.
+  config.active_support.disallowed_deprecation = :raise
+
+  # Tell Active Support which deprecation messages to disallow.
+  config.active_support.disallowed_deprecation_warnings = []
+
   # Raise an error on page load if there are pending migrations.
   config.active_record.migration_error = :page_load
 
@@ -52,10 +64,12 @@
   # Suppress logger output for asset requests.
   config.assets.quiet = true
 
-  # Raises error for missing translations
-  # config.action_view.raise_on_missing_translations = true
+  # Raises error for missing translations.
+  # config.i18n.raise_on_missing_translations = true
 
-  # Use an evented file watcher to asynchronously detect changes in source code,
-  # routes, locales, etc. This feature depends on the listen gem.
-  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
+  # Annotate rendered view with file names.
+  # config.action_view.annotate_rendered_view_with_filenames = true
+
+  # Uncomment if you wish to allow Action Cable access from any origin.
+  # config.action_cable.disable_request_forgery_protection = true
 end
diff --git a/config/environments/production.rb b/config/environments/production.rb
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -1,3 +1,5 @@
+require "active_support/core_ext/integer/time"
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
@@ -20,38 +22,35 @@
 
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
-  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
+  config.public_file_server.enabled = ENV["RAILS_SERVE_STATIC_FILES"].present?
 
-  # Compress JavaScripts and CSS.
-  config.assets.js_compressor = :uglifier
+  # Compress CSS using a preprocessor.
   # config.assets.css_compressor = :sass
 
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
-
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
-  # config.action_controller.asset_host = 'http://assets.example.com'
+  # config.asset_host = "http://assets.example.com"
 
   # Specifies the header that your server uses for sending files.
-  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
-  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
+  # config.action_dispatch.x_sendfile_header = "X-Sendfile" # for Apache
+  # config.action_dispatch.x_sendfile_header = "X-Accel-Redirect" # for NGINX
 
-  # Store uploaded files on the local file system (see config/storage.yml for options)
+  # Store uploaded files on the local file system (see config/storage.yml for options).
   config.active_storage.service = :local
 
-  # Mount Action Cable outside main process or domain
+  # Mount Action Cable outside main process or domain.
   # config.action_cable.mount_path = nil
-  # config.action_cable.url = 'wss://example.com/cable'
-  # config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]
+  # config.action_cable.url = "wss://example.com/cable"
+  # config.action_cable.allowed_request_origins = [ "http://example.com", /http:\/\/example.*/ ]
 
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   # config.force_ssl = true
 
-  # Use the lowest log level to ensure availability of diagnostic information
-  # when problems arise.
-  config.log_level = :debug
+  # Include generic and useful information about system operation, but avoid logging too much
+  # information to avoid inadvertent exposure of personally identifiable information (PII).
+  config.log_level = :info
 
   # Prepend all log lines with the following tags.
   config.log_tags = [ :request_id ]
@@ -59,9 +58,9 @@
   # Use a different cache store in production.
   # config.cache_store = :mem_cache_store
 
-  # Use a real queuing backend for Active Job (and separate queues per environment)
+  # Use a real queuing backend for Active Job (and separate queues per environment).
   # config.active_job.queue_adapter     = :resque
-  # config.active_job.queue_name_prefix = "cafe_grader_#{Rails.env}"
+  # config.active_job.queue_name_prefix = "cafe_grader_production"
 
   config.action_mailer.perform_caching = false
 
@@ -76,12 +75,18 @@
   # Send deprecation notices to registered listeners.
   config.active_support.deprecation = :notify
 
+  # Log disallowed deprecations.
+  config.active_support.disallowed_deprecation = :log
+
+  # Tell Active Support which deprecation messages to disallow.
+  config.active_support.disallowed_deprecation_warnings = []
+
   # Use default logging formatter so that PID and timestamp are not suppressed.
   config.log_formatter = ::Logger::Formatter.new
 
   # Use a different logger for distributed setups.
-  # require 'syslog/logger'
-  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
+  # require "syslog/logger"
+  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new "app-name")
 
   if ENV["RAILS_LOG_TO_STDOUT"].present?
     logger           = ActiveSupport::Logger.new(STDOUT)
diff --git a/config/environments/test.rb b/config/environments/test.rb
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -1,26 +1,31 @@
+require "active_support/core_ext/integer/time"
+
+# The test environment is used exclusively to run your application's
+# test suite. You never need to work with it otherwise. Remember that
+# your test database is "scratch space" for the test suite and is wiped
+# and recreated between test runs. Don't rely on the data there!
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
-  # The test environment is used exclusively to run your application's
-  # test suite. You never need to work with it otherwise. Remember that
-  # your test database is "scratch space" for the test suite and is wiped
-  # and recreated between test runs. Don't rely on the data there!
+  # Turn false under Spring and add config.action_view.cache_template_loading = true.
   config.cache_classes = true
 
-  # Do not eager load code on boot. This avoids loading your whole application
-  # just for the purpose of running a single test. If you are using a tool that
-  # preloads Rails for running tests, you may have to set it to true.
-  config.eager_load = false
+  # Eager loading loads your whole application. When running a single test locally,
+  # this probably isn't necessary. It's a good idea to do in a continuous integration
+  # system, or in some way before deploying your code.
+  config.eager_load = ENV["CI"].present?
 
   # Configure public file server for tests with Cache-Control for performance.
   config.public_file_server.enabled = true
   config.public_file_server.headers = {
-    'Cache-Control' => "public, max-age=#{1.hour.to_i}"
+    "Cache-Control" => "public, max-age=#{1.hour.to_i}"
   }
 
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
   config.action_controller.perform_caching = false
+  config.cache_store = :null_store
 
   # Raise exceptions instead of rendering exception templates.
   config.action_dispatch.show_exceptions = false
@@ -28,7 +33,7 @@
   # Disable request forgery protection in test environment.
   config.action_controller.allow_forgery_protection = false
 
-  # Store uploaded files on the local file system in a temporary directory
+  # Store uploaded files on the local file system in a temporary directory.
   config.active_storage.service = :test
 
   config.action_mailer.perform_caching = false
@@ -41,6 +46,15 @@
   # Print deprecation notices to the stderr.
   config.active_support.deprecation = :stderr
 
-  # Raises error for missing translations
-  # config.action_view.raise_on_missing_translations = true
+  # Raise exceptions for disallowed deprecations.
+  config.active_support.disallowed_deprecation = :raise
+
+  # Tell Active Support which deprecation messages to disallow.
+  config.active_support.disallowed_deprecation_warnings = []
+
+  # Raises error for missing translations.
+  # config.i18n.raise_on_missing_translations = true
+
+  # Annotate rendered view with file names.
+  # config.action_view.annotate_rendered_view_with_filenames = true
 end
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -1,7 +1,7 @@
 # Be sure to restart your server when you modify this file.
 
 # Version of your assets, change this if you want to expire all your assets.
-Rails.application.config.assets.version = '1.0'
+Rails.application.config.assets.version = "1.0"
 
 # Add additional assets to the asset load path.
 # Rails.application.config.assets.paths << Emoji.images_path
diff --git a/config/initializers/backtrace_silencers.rb b/config/initializers/backtrace_silencers.rb
--- a/config/initializers/backtrace_silencers.rb
+++ b/config/initializers/backtrace_silencers.rb
@@ -1,7 +1,8 @@
 # Be sure to restart your server when you modify this file.
 
 # You can add backtrace silencers for libraries that you're using but don't wish to see in your backtraces.
-# Rails.backtrace_cleaner.add_silencer { |line| line =~ /my_noisy_library/ }
+# Rails.backtrace_cleaner.add_silencer { |line| /my_noisy_library/.match?(line) }
 
-# You can also remove all the silencers if you're trying to debug a problem that might stem from framework code.
-# Rails.backtrace_cleaner.remove_silencers!
+# You can also remove all the silencers if you're trying to debug a problem that might stem from framework code
+# by setting BACKTRACE=1 before calling your invocation, like "BACKTRACE=1 ./bin/rails runner 'MyClass.perform'".
+Rails.backtrace_cleaner.remove_silencers! if ENV["BACKTRACE"]
diff --git a/config/initializers/content_security_policy.rb b/config/initializers/content_security_policy.rb
--- a/config/initializers/content_security_policy.rb
+++ b/config/initializers/content_security_policy.rb
@@ -4,22 +4,23 @@
 # For further information see the following documentation
 # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
 
-# Rails.application.config.content_security_policy do |policy|
-#   policy.default_src :self, :https
-#   policy.font_src    :self, :https, :data
-#   policy.img_src     :self, :https, :data
-#   policy.object_src  :none
-#   policy.script_src  :self, :https
-#   policy.style_src   :self, :https
-
-#   # Specify URI for violation reports
-#   # policy.report_uri "/csp-violation-report-endpoint"
+# Rails.application.configure do
+#   config.content_security_policy do |policy|
+#     policy.default_src :self, :https
+#     policy.font_src    :self, :https, :data
+#     policy.img_src     :self, :https, :data
+#     policy.object_src  :none
+#     policy.script_src  :self, :https
+#     policy.style_src   :self, :https
+#     # Specify URI for violation reports
+#     # policy.report_uri "/csp-violation-report-endpoint"
+#   end
+#
+#   # Generate session nonces for permitted importmap and inline scripts
+#   config.content_security_policy_nonce_generator = ->(request) { request.session.id.to_s }
+#   config.content_security_policy_nonce_directives = %w(script-src)
+#
+#   # Report CSP violations to a specified URI. See:
+#   # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only
+#   # config.content_security_policy_report_only = true
 # end
-
-# If you are using UJS then enable automatic nonce generation
-# Rails.application.config.content_security_policy_nonce_generator = -> request { SecureRandom.base64(16) }
-
-# Report CSP violations to a specified URI
-# For further information see the following documentation:
-# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only
-# Rails.application.config.content_security_policy_report_only = true
diff --git a/config/initializers/filter_parameter_logging.rb b/config/initializers/filter_parameter_logging.rb
--- a/config/initializers/filter_parameter_logging.rb
+++ b/config/initializers/filter_parameter_logging.rb
@@ -1,4 +1,6 @@
 # Be sure to restart your server when you modify this file.
 
 # Configure sensitive parameters which will be filtered from the log file.
-Rails.application.config.filter_parameters += [:password]
+Rails.application.config.filter_parameters += [
+  :passw, :secret, :token, :_key, :crypt, :salt, :certificate, :otp, :ssn
+]
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -4,13 +4,13 @@
 # are locale specific, and you may define rules for as many different
 # locales as you wish. All of these examples are active by default:
 # ActiveSupport::Inflector.inflections(:en) do |inflect|
-#   inflect.plural /^(ox)$/i, '\1en'
-#   inflect.singular /^(ox)en/i, '\1'
-#   inflect.irregular 'person', 'people'
+#   inflect.plural /^(ox)$/i, "\\1en"
+#   inflect.singular /^(ox)en/i, "\\1"
+#   inflect.irregular "person", "people"
 #   inflect.uncountable %w( fish sheep )
 # end
 
 # These inflection rules are supported but not enabled by default:
 # ActiveSupport::Inflector.inflections(:en) do |inflect|
-#   inflect.acronym 'RESTful'
+#   inflect.acronym "RESTful"
 # end
diff --git a/config/initializers/new_framework_defaults_6_1.rb b/config/initializers/new_framework_defaults_6_1.rb
new file mode 100644
--- /dev/null
+++ b/config/initializers/new_framework_defaults_6_1.rb
@@ -0,0 +1,67 @@
+# Be sure to restart your server when you modify this file.
+#
+# This file contains migration options to ease your Rails 6.1 upgrade.
+#
+# Once upgraded flip defaults one by one to migrate to the new default.
+#
+# Read the Guide for Upgrading Ruby on Rails for more info on each option.
+
+# Support for inversing belongs_to -> has_many Active Record associations.
+# Rails.application.config.active_record.has_many_inversing = true
+
+# Track Active Storage variants in the database.
+# Rails.application.config.active_storage.track_variants = true
+
+# Apply random variation to the delay when retrying failed jobs.
+# Rails.application.config.active_job.retry_jitter = 0.15
+
+# Stop executing `after_enqueue`/`after_perform` callbacks if
+# `before_enqueue`/`before_perform` respectively halts with `throw :abort`.
+# Rails.application.config.active_job.skip_after_callbacks_if_terminated = true
+
+# Specify cookies SameSite protection level: either :none, :lax, or :strict.
+#
+# This change is not backwards compatible with earlier Rails versions.
+# It's best enabled when your entire app is migrated and stable on 6.1.
+# Rails.application.config.action_dispatch.cookies_same_site_protection = :lax
+
+# Generate CSRF tokens that are encoded in URL-safe Base64.
+#
+# This change is not backwards compatible with earlier Rails versions.
+# It's best enabled when your entire app is migrated and stable on 6.1.
+# Rails.application.config.action_controller.urlsafe_csrf_tokens = true
+
+# Specify whether `ActiveSupport::TimeZone.utc_to_local` returns a time with an
+# UTC offset or a UTC time.
+# ActiveSupport.utc_to_local_returns_utc_offset_times = true
+
+# Change the default HTTP status code to `308` when redirecting non-GET/HEAD
+# requests to HTTPS in `ActionDispatch::SSL` middleware.
+# Rails.application.config.action_dispatch.ssl_default_redirect_status = 308
+
+# Use new connection handling API. For most applications this won't have any
+# effect. For applications using multiple databases, this new API provides
+# support for granular connection swapping.
+# Rails.application.config.active_record.legacy_connection_handling = false
+
+# Make `form_with` generate non-remote forms by default.
+# Rails.application.config.action_view.form_with_generates_remote_forms = false
+
+# Set the default queue name for the analysis job to the queue adapter default.
+# Rails.application.config.active_storage.queues.analysis = nil
+
+# Set the default queue name for the purge job to the queue adapter default.
+# Rails.application.config.active_storage.queues.purge = nil
+
+# Set the default queue name for the incineration job to the queue adapter default.
+# Rails.application.config.action_mailbox.queues.incineration = nil
+
+# Set the default queue name for the routing job to the queue adapter default.
+# Rails.application.config.action_mailbox.queues.routing = nil
+
+# Set the default queue name for the mail deliver job to the queue adapter default.
+# Rails.application.config.action_mailer.deliver_later_queue_name = nil
+
+# Generate a `Link` header that gives a hint to modern browsers about
+# preloading assets when using `javascript_include_tag` and `stylesheet_link_tag`.
+# Rails.application.config.action_view.preload_links_header = true
diff --git a/config/initializers/new_framework_defaults_7_0.rb b/config/initializers/new_framework_defaults_7_0.rb
new file mode 100644
--- /dev/null
+++ b/config/initializers/new_framework_defaults_7_0.rb
@@ -0,0 +1,117 @@
+# Be sure to restart your server when you modify this file.
+#
+# This file eases your Rails 7.0 framework defaults upgrade.
+#
+# Uncomment each configuration one by one to switch to the new default.
+# Once your application is ready to run with all new defaults, you can remove
+# this file and set the `config.load_defaults` to `7.0`.
+#
+# Read the Guide for Upgrading Ruby on Rails for more info on each option.
+# https://guides.rubyonrails.org/upgrading_ruby_on_rails.html
+
+# `button_to` view helper will render `<button>` element, regardless of whether
+# or not the content is passed as the first argument or as a block.
+# Rails.application.config.action_view.button_to_generates_button_tag = true
+
+# `stylesheet_link_tag` view helper will not render the media attribute by default.
+# Rails.application.config.action_view.apply_stylesheet_media_default = false
+
+# Change the digest class for the key generators to `OpenSSL::Digest::SHA256`.
+# Changing this default means invalidate all encrypted messages generated by
+# your application and, all the encrypted cookies. Only change this after you
+# rotated all the messages using the key rotator.
+#
+# See upgrading guide for more information on how to build a rotator.
+# https://guides.rubyonrails.org/v7.0/upgrading_ruby_on_rails.html
+# Rails.application.config.active_support.key_generator_hash_digest_class = OpenSSL::Digest::SHA256
+
+# Change the digest class for ActiveSupport::Digest.
+# Changing this default means that for example Etags change and
+# various cache keys leading to cache invalidation.
+# Rails.application.config.active_support.hash_digest_class = OpenSSL::Digest::SHA256
+
+# Don't override ActiveSupport::TimeWithZone.name and use the default Ruby
+# implementation.
+# Rails.application.config.active_support.remove_deprecated_time_with_zone_name = true
+
+# Change the format of the cache entry.
+# Changing this default means that all new cache entries added to the cache
+# will have a different format that is not supported by Rails 6.1 applications.
+# Only change this value after your application is fully deployed to Rails 7.0
+# and you have no plans to rollback.
+# Rails.application.config.active_support.cache_format_version = 7.0
+
+# Calls `Rails.application.executor.wrap` around test cases.
+# This makes test cases behave closer to an actual request or job.
+# Several features that are normally disabled in test, such as Active Record query cache
+# and asynchronous queries will then be enabled.
+# Rails.application.config.active_support.executor_around_test_case = true
+
+# Define the isolation level of most of Rails internal state.
+# If you use a fiber based server or job processor, you should set it to `:fiber`.
+# Otherwise the default of `:thread` if preferable.
+# Rails.application.config.active_support.isolation_level = :thread
+
+# Set both the `:open_timeout` and `:read_timeout` values for `:smtp` delivery method.
+# Rails.application.config.action_mailer.smtp_timeout = 5
+
+# The ActiveStorage video previewer will now use scene change detection to generate
+# better preview images (rather than the previous default of using the first frame
+# of the video).
+# Rails.application.config.active_storage.video_preview_arguments =
+#   "-vf 'select=eq(n\\,0)+eq(key\\,1)+gt(scene\\,0.015),loop=loop=-1:size=2,trim=start_frame=1' -frames:v 1 -f image2"
+
+# Automatically infer `inverse_of` for associations with a scope.
+# Rails.application.config.active_record.automatic_scope_inversing = true
+
+# Raise when running tests if fixtures contained foreign key violations
+# Rails.application.config.active_record.verify_foreign_keys_for_fixtures = true
+
+# Disable partial inserts.
+# This default means that all columns will be referenced in INSERT queries
+# regardless of whether they have a default or not.
+# Rails.application.config.active_record.partial_inserts = false
+#
+# Protect from open redirect attacks in `redirect_back_or_to` and `redirect_to`.
+# Rails.application.config.action_controller.raise_on_open_redirects = true
+
+# Change the variant processor for Active Storage.
+# Changing this default means updating all places in your code that
+# generate variants to use image processing macros and ruby-vips
+# operations. See the upgrading guide for detail on the changes required.
+# The `:mini_magick` option is not deprecated; it's fine to keep using it.
+# Rails.application.config.active_storage.variant_processor = :vips
+
+# If you're upgrading and haven't set `cookies_serializer` previously, your cookie serializer
+# was `:marshal`. Convert all cookies to JSON, using the `:hybrid` formatter.
+#
+# If you're confident all your cookies are JSON formatted, you can switch to the `:json` formatter.
+#
+# Continue to use `:marshal` for backward-compatibility with old cookies.
+#
+# If you have configured the serializer elsewhere, you can remove this.
+#
+# See https://guides.rubyonrails.org/action_controller_overview.html#cookies for more information.
+# Rails.application.config.action_dispatch.cookies_serializer = :hybrid
+
+# Enable parameter wrapping for JSON.
+# Previously this was set in an initializer. It's fine to keep using that initializer if you've customized it.
+# To disable parameter wrapping entirely, set this config to `false`.
+# Rails.application.config.action_controller.wrap_parameters_by_default = true
+
+# Specifies whether generated namespaced UUIDs follow the RFC 4122 standard for namespace IDs provided as a
+# `String` to `Digest::UUID.uuid_v3` or `Digest::UUID.uuid_v5` method calls.
+#
+# See https://guides.rubyonrails.org/configuring.html#config-active-support-use-rfc4122-namespaced-uuids for
+# more information.
+# Rails.application.config.active_support.use_rfc4122_namespaced_uuids = true
+
+# Change the default headers to disable browsers' flawed legacy XSS protection.
+# Rails.application.config.action_dispatch.default_headers = {
+#   "X-Frame-Options" => "SAMEORIGIN",
+#   "X-XSS-Protection" => "0",
+#   "X-Content-Type-Options" => "nosniff",
+#   "X-Download-Options" => "noopen",
+#   "X-Permitted-Cross-Domain-Policies" => "none",
+#   "Referrer-Policy" => "strict-origin-when-cross-origin"
+# }
diff --git a/config/initializers/permissions_policy.rb b/config/initializers/permissions_policy.rb
new file mode 100644
--- /dev/null
+++ b/config/initializers/permissions_policy.rb
@@ -0,0 +1,11 @@
+# Define an application-wide HTTP permissions policy. For further
+# information see https://developers.google.com/web/updates/2018/06/feature-policy
+#
+# Rails.application.config.permissions_policy do |f|
+#   f.camera      :none
+#   f.gyroscope   :none
+#   f.microphone  :none
+#   f.usb         :none
+#   f.fullscreen  :self
+#   f.payment     :self, "https://secure.example.com"
+# end
diff --git a/config/puma.rb b/config/puma.rb
--- a/config/puma.rb
+++ b/config/puma.rb
@@ -4,19 +4,28 @@
 # the maximum value specified for Puma. Default is set to 5 threads for minimum
 # and maximum; this matches the default thread size of Active Record.
 #
-threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }
-threads threads_count, threads_count
+max_threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }
+min_threads_count = ENV.fetch("RAILS_MIN_THREADS") { max_threads_count }
+threads min_threads_count, max_threads_count
+
+# Specifies the `worker_timeout` threshold that Puma will use to wait before
+# terminating a worker in development environments.
+#
+worker_timeout 3600 if ENV.fetch("RAILS_ENV", "development") == "development"
 
 # Specifies the `port` that Puma will listen on to receive requests; default is 3000.
 #
-port        ENV.fetch("PORT") { 3000 }
+port ENV.fetch("PORT") { 3000 }
 
 # Specifies the `environment` that Puma will run in.
 #
 environment ENV.fetch("RAILS_ENV") { "development" }
 
+# Specifies the `pidfile` that Puma will use.
+pidfile ENV.fetch("PIDFILE") { "tmp/pids/server.pid" }
+
 # Specifies the number of `workers` to boot in clustered mode.
-# Workers are forked webserver processes. If using threads and workers together
+# Workers are forked web server processes. If using threads and workers together
 # the concurrency of the application would be max `threads` * `workers`.
 # Workers do not work on JRuby or Windows (both of which do not support
 # processes).
diff --git a/config/spring.rb b/config/spring.rb
--- a/config/spring.rb
+++ b/config/spring.rb
@@ -1,6 +1,6 @@
-%w(
-  .ruby-version
-  .rbenv-vars
-  tmp/restart.txt
-  tmp/caching-dev.txt
-).each { |path| Spring.watch(path) }
+Spring.watch(
+  ".ruby-version",
+  ".rbenv-vars",
+  "tmp/restart.txt",
+  "tmp/caching-dev.txt"
+)
diff --git a/db/migrate/001_create_users.rb b/db/migrate/001_create_users.rb
--- a/db/migrate/001_create_users.rb
+++ b/db/migrate/001_create_users.rb
@@ -1,6 +1,6 @@
-class CreateUsers < ActiveRecord::Migration
+class CreateUsers < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :users do |t|
+    create_table :users, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :login, :string, :limit => 10
       t.column :full_name, :string
       t.column :hashed_password, :string
diff --git a/db/migrate/002_create_problems.rb b/db/migrate/002_create_problems.rb
--- a/db/migrate/002_create_problems.rb
+++ b/db/migrate/002_create_problems.rb
@@ -1,6 +1,6 @@
-class CreateProblems < ActiveRecord::Migration
+class CreateProblems < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :problems do |t|
+    create_table :problems, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :name, :string, :limit => 30
       t.column :full_name, :string
       t.column :full_score, :integer
diff --git a/db/migrate/003_create_submissions.rb b/db/migrate/003_create_submissions.rb
--- a/db/migrate/003_create_submissions.rb
+++ b/db/migrate/003_create_submissions.rb
@@ -1,6 +1,6 @@
-class CreateSubmissions < ActiveRecord::Migration
+class CreateSubmissions < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :submissions do |t|
+    create_table :submissions, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :user_id, :integer
       t.column :problem_id, :integer
       t.column :language_id, :integer
diff --git a/db/migrate/004_create_languages.rb b/db/migrate/004_create_languages.rb
--- a/db/migrate/004_create_languages.rb
+++ b/db/migrate/004_create_languages.rb
@@ -1,6 +1,6 @@
-class CreateLanguages < ActiveRecord::Migration
+class CreateLanguages < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :languages do |t|
+    create_table :languages, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :name, :string, :limit => 10
       t.column :pretty_name, :string
     end
diff --git a/db/migrate/005_add_index_to_submissions.rb b/db/migrate/005_add_index_to_submissions.rb
--- a/db/migrate/005_add_index_to_submissions.rb
+++ b/db/migrate/005_add_index_to_submissions.rb
@@ -1,4 +1,4 @@
-class AddIndexToSubmissions < ActiveRecord::Migration
+class AddIndexToSubmissions < ActiveRecord::Migration[4.2]
   def self.up
     add_index :submissions, [:user_id, :problem_id]
   end
diff --git a/db/migrate/006_create_roles.rb b/db/migrate/006_create_roles.rb
--- a/db/migrate/006_create_roles.rb
+++ b/db/migrate/006_create_roles.rb
@@ -1,10 +1,10 @@
-class CreateRoles < ActiveRecord::Migration
+class CreateRoles < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :roles do |t|
+    create_table :roles, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'name', :string
     end
 
-    create_table :roles_users, :id => false do |t|
+    create_table :roles_users, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'role_id', :integer
       t.column 'user_id', :integer
     end
diff --git a/db/migrate/007_create_rights.rb b/db/migrate/007_create_rights.rb
--- a/db/migrate/007_create_rights.rb
+++ b/db/migrate/007_create_rights.rb
@@ -1,12 +1,12 @@
-class CreateRights < ActiveRecord::Migration
+class CreateRights < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :rights do |t|
+    create_table :rights, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'name', :string
       t.column 'controller', :string
       t.column 'action', :string
     end
 
-    create_table :rights_roles, :id => false do |t|
+    create_table :rights_roles, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'right_id', :integer
       t.column 'role_id', :integer
     end
diff --git a/db/migrate/008_create_tasks.rb b/db/migrate/008_create_tasks.rb
--- a/db/migrate/008_create_tasks.rb
+++ b/db/migrate/008_create_tasks.rb
@@ -1,6 +1,6 @@
-class CreateTasks < ActiveRecord::Migration
+class CreateTasks < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :tasks do |t|
+    create_table :tasks, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'submission_id', :integer
       t.column 'created_at', :datetime
     end
diff --git a/db/migrate/009_add_sessions.rb b/db/migrate/009_add_sessions.rb
--- a/db/migrate/009_add_sessions.rb
+++ b/db/migrate/009_add_sessions.rb
@@ -1,6 +1,6 @@
-class AddSessions < ActiveRecord::Migration
+class AddSessions < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :sessions do |t|
+    create_table :sessions, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :session_id, :string
       t.column :data, :text
       t.column :updated_at, :datetime
diff --git a/db/migrate/011_add_language_ext.rb b/db/migrate/011_add_language_ext.rb
--- a/db/migrate/011_add_language_ext.rb
+++ b/db/migrate/011_add_language_ext.rb
@@ -1,4 +1,4 @@
-class AddLanguageExt < ActiveRecord::Migration
+class AddLanguageExt < ActiveRecord::Migration[4.2]
   def self.up
     add_column :languages, :ext, :string, :limit => 10
 
diff --git a/db/migrate/012_add_email_to_users.rb b/db/migrate/012_add_email_to_users.rb
--- a/db/migrate/012_add_email_to_users.rb
+++ b/db/migrate/012_add_email_to_users.rb
@@ -1,4 +1,4 @@
-class AddEmailToUsers < ActiveRecord::Migration
+class AddEmailToUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_column :users, :email, :string
   end
diff --git a/db/migrate/013_add_url_to_problem.rb b/db/migrate/013_add_url_to_problem.rb
--- a/db/migrate/013_add_url_to_problem.rb
+++ b/db/migrate/013_add_url_to_problem.rb
@@ -1,4 +1,4 @@
-class AddUrlToProblem < ActiveRecord::Migration
+class AddUrlToProblem < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :url, :string
   end
diff --git a/db/migrate/014_create_grader_processes.rb b/db/migrate/014_create_grader_processes.rb
--- a/db/migrate/014_create_grader_processes.rb
+++ b/db/migrate/014_create_grader_processes.rb
@@ -1,6 +1,6 @@
-class CreateGraderProcesses < ActiveRecord::Migration
+class CreateGraderProcesses < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :grader_processes do |t|
+    create_table :grader_processes, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :ip, :string, :limit => 20
       t.column :pid, :integer
       t.column :mode, :string
diff --git a/db/migrate/015_add_status_to_tasks.rb b/db/migrate/015_add_status_to_tasks.rb
--- a/db/migrate/015_add_status_to_tasks.rb
+++ b/db/migrate/015_add_status_to_tasks.rb
@@ -1,4 +1,4 @@
-class AddStatusToTasks < ActiveRecord::Migration
+class AddStatusToTasks < ActiveRecord::Migration[4.2]
   def self.up
     add_column :tasks, :status, :integer
     add_column :tasks, :updated_at, :datetime
diff --git a/db/migrate/016_add_task_to_grader_process.rb b/db/migrate/016_add_task_to_grader_process.rb
--- a/db/migrate/016_add_task_to_grader_process.rb
+++ b/db/migrate/016_add_task_to_grader_process.rb
@@ -1,4 +1,4 @@
-class AddTaskToGraderProcess < ActiveRecord::Migration
+class AddTaskToGraderProcess < ActiveRecord::Migration[4.2]
   def self.up
     add_column :grader_processes, :task_id, :integer
   end
diff --git a/db/migrate/017_rename_grader_process_column_ip_to_host.rb b/db/migrate/017_rename_grader_process_column_ip_to_host.rb
--- a/db/migrate/017_rename_grader_process_column_ip_to_host.rb
+++ b/db/migrate/017_rename_grader_process_column_ip_to_host.rb
@@ -1,4 +1,4 @@
-class RenameGraderProcessColumnIpToHost < ActiveRecord::Migration
+class RenameGraderProcessColumnIpToHost < ActiveRecord::Migration[4.2]
   def self.up
     rename_column :grader_processes, :ip, :host
   end
diff --git a/db/migrate/018_add_number_to_submissions.rb b/db/migrate/018_add_number_to_submissions.rb
--- a/db/migrate/018_add_number_to_submissions.rb
+++ b/db/migrate/018_add_number_to_submissions.rb
@@ -1,4 +1,4 @@
-class AddNumberToSubmissions < ActiveRecord::Migration
+class AddNumberToSubmissions < ActiveRecord::Migration[4.2]
   def self.up
     add_column :submissions, :number, :integer
 
diff --git a/db/migrate/019_create_test_requests.rb b/db/migrate/019_create_test_requests.rb
--- a/db/migrate/019_create_test_requests.rb
+++ b/db/migrate/019_create_test_requests.rb
@@ -1,6 +1,6 @@
-class CreateTestRequests < ActiveRecord::Migration
+class CreateTestRequests < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :test_requests do |t|
+    create_table :test_requests, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :user_id, :integer
       t.column :problem_id, :integer
       t.column :submission_id, :integer
@@ -10,7 +10,6 @@
 
       # these are similar to tasks
       t.column :status, :integer
-      t.column :updated_at, :datetime
 
       # these are intentionally similar to submissions
       t.column :submitted_at, :datetime
diff --git a/db/migrate/021_change_compiler_message_type_test_request.rb b/db/migrate/021_change_compiler_message_type_test_request.rb
--- a/db/migrate/021_change_compiler_message_type_test_request.rb
+++ b/db/migrate/021_change_compiler_message_type_test_request.rb
@@ -1,4 +1,4 @@
-class ChangeCompilerMessageTypeTestRequest < ActiveRecord::Migration
+class ChangeCompilerMessageTypeTestRequest < ActiveRecord::Migration[4.2]
   def self.up
     change_column :test_requests, :compiler_message, :text
   end
diff --git a/db/migrate/022_create_configurations.rb b/db/migrate/022_create_configurations.rb
--- a/db/migrate/022_create_configurations.rb
+++ b/db/migrate/022_create_configurations.rb
@@ -1,6 +1,6 @@
-class CreateConfigurations < ActiveRecord::Migration
+class CreateConfigurations < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :configurations do |t|
+    create_table :configurations, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :key, :string
       t.column :value_type, :string
       t.column :value, :string
diff --git a/db/migrate/023_add_runstat_columns_to_test_request.rb b/db/migrate/023_add_runstat_columns_to_test_request.rb
--- a/db/migrate/023_add_runstat_columns_to_test_request.rb
+++ b/db/migrate/023_add_runstat_columns_to_test_request.rb
@@ -1,4 +1,4 @@
-class AddRunstatColumnsToTestRequest < ActiveRecord::Migration
+class AddRunstatColumnsToTestRequest < ActiveRecord::Migration[4.2]
   def self.up
     add_column :test_requests, :running_time, :float
     add_column :test_requests, :exit_status, :string
diff --git a/db/migrate/024_create_sites.rb b/db/migrate/024_create_sites.rb
--- a/db/migrate/024_create_sites.rb
+++ b/db/migrate/024_create_sites.rb
@@ -1,6 +1,6 @@
-class CreateSites < ActiveRecord::Migration
+class CreateSites < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :sites do |t|
+    create_table :sites, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :name
       t.boolean :started
       t.datetime :start_time
diff --git a/db/migrate/025_add_site_to_user_and_add_default_site.rb b/db/migrate/025_add_site_to_user_and_add_default_site.rb
--- a/db/migrate/025_add_site_to_user_and_add_default_site.rb
+++ b/db/migrate/025_add_site_to_user_and_add_default_site.rb
@@ -1,4 +1,4 @@
-class AddSiteToUserAndAddDefaultSite < ActiveRecord::Migration
+class AddSiteToUserAndAddDefaultSite < ActiveRecord::Migration[4.2]
   def self.up
     default_site = Site.new({:name => 'default',
                               :started => false})
diff --git a/db/migrate/026_add_body_to_problems.rb b/db/migrate/026_add_body_to_problems.rb
--- a/db/migrate/026_add_body_to_problems.rb
+++ b/db/migrate/026_add_body_to_problems.rb
@@ -1,4 +1,4 @@
-class AddBodyToProblems < ActiveRecord::Migration
+class AddBodyToProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :body, :text
   end
diff --git a/db/migrate/027_create_descriptions.rb b/db/migrate/027_create_descriptions.rb
--- a/db/migrate/027_create_descriptions.rb
+++ b/db/migrate/027_create_descriptions.rb
@@ -1,6 +1,6 @@
-class CreateDescriptions < ActiveRecord::Migration
+class CreateDescriptions < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :descriptions do |t|
+    create_table :descriptions, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :body, :text
       t.column :markdowned, :boolean
       t.timestamps
diff --git a/db/migrate/028_refactor_problem_body_to_description.rb b/db/migrate/028_refactor_problem_body_to_description.rb
--- a/db/migrate/028_refactor_problem_body_to_description.rb
+++ b/db/migrate/028_refactor_problem_body_to_description.rb
@@ -1,4 +1,4 @@
-class RefactorProblemBodyToDescription < ActiveRecord::Migration
+class RefactorProblemBodyToDescription < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :description_id, :integer
     Problem.reset_column_information
diff --git a/db/migrate/029_add_test_allowed_to_problems.rb b/db/migrate/029_add_test_allowed_to_problems.rb
--- a/db/migrate/029_add_test_allowed_to_problems.rb
+++ b/db/migrate/029_add_test_allowed_to_problems.rb
@@ -1,4 +1,4 @@
-class AddTestAllowedToProblems < ActiveRecord::Migration
+class AddTestAllowedToProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :test_allowed, :boolean
     Problem.reset_column_information
diff --git a/db/migrate/030_create_announcements.rb b/db/migrate/030_create_announcements.rb
--- a/db/migrate/030_create_announcements.rb
+++ b/db/migrate/030_create_announcements.rb
@@ -1,6 +1,6 @@
-class CreateAnnouncements < ActiveRecord::Migration
+class CreateAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :announcements do |t|
+    create_table :announcements, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :author
       t.text :body
       t.boolean :published
diff --git a/db/migrate/031_add_supports_for_output_only_problems.rb b/db/migrate/031_add_supports_for_output_only_problems.rb
--- a/db/migrate/031_add_supports_for_output_only_problems.rb
+++ b/db/migrate/031_add_supports_for_output_only_problems.rb
@@ -1,4 +1,4 @@
-class AddSupportsForOutputOnlyProblems < ActiveRecord::Migration
+class AddSupportsForOutputOnlyProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :submissions, :source_filename, :string
     add_column :problems, :output_only, :boolean
diff --git a/db/migrate/032_create_messages.rb b/db/migrate/032_create_messages.rb
--- a/db/migrate/032_create_messages.rb
+++ b/db/migrate/032_create_messages.rb
@@ -1,6 +1,6 @@
-class CreateMessages < ActiveRecord::Migration
+class CreateMessages < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :messages do |t|
+    create_table :messages, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column "sender_id", :integer
       t.column "receiver_id", :integer
       t.column "replying_message_id", :integer
diff --git a/db/migrate/033_add_task_type_to_grader_processes.rb b/db/migrate/033_add_task_type_to_grader_processes.rb
--- a/db/migrate/033_add_task_type_to_grader_processes.rb
+++ b/db/migrate/033_add_task_type_to_grader_processes.rb
@@ -1,4 +1,4 @@
-class AddTaskTypeToGraderProcesses < ActiveRecord::Migration
+class AddTaskTypeToGraderProcesses < ActiveRecord::Migration[4.2]
   def self.up
     add_column 'grader_processes', 'task_type', :string
   end
diff --git a/db/migrate/034_create_countries.rb b/db/migrate/034_create_countries.rb
--- a/db/migrate/034_create_countries.rb
+++ b/db/migrate/034_create_countries.rb
@@ -1,6 +1,6 @@
-class CreateCountries < ActiveRecord::Migration
+class CreateCountries < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :countries do |t|
+    create_table :countries, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column :name, :string
       t.timestamps
     end
diff --git a/db/migrate/035_add_country_to_sites_and_users.rb b/db/migrate/035_add_country_to_sites_and_users.rb
--- a/db/migrate/035_add_country_to_sites_and_users.rb
+++ b/db/migrate/035_add_country_to_sites_and_users.rb
@@ -1,4 +1,4 @@
-class AddCountryToSitesAndUsers < ActiveRecord::Migration
+class AddCountryToSitesAndUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_column 'sites', 'country_id', :integer
     add_column 'sites', 'password', :string
diff --git a/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb b/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb
--- a/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb
+++ b/db/migrate/20081107145815_add_frontpage_flag_to_announcement.rb
@@ -1,4 +1,4 @@
-class AddFrontpageFlagToAnnouncement < ActiveRecord::Migration
+class AddFrontpageFlagToAnnouncement < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, "frontpage", :boolean, :default => 0
   end
diff --git a/db/migrate/20081204122651_add_activated_to_users.rb b/db/migrate/20081204122651_add_activated_to_users.rb
--- a/db/migrate/20081204122651_add_activated_to_users.rb
+++ b/db/migrate/20081204122651_add_activated_to_users.rb
@@ -1,4 +1,4 @@
-class AddActivatedToUsers < ActiveRecord::Migration
+class AddActivatedToUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_column :users, :activated, :boolean, :default => 0
 
diff --git a/db/migrate/20081210021333_add_timestamps_to_users.rb b/db/migrate/20081210021333_add_timestamps_to_users.rb
--- a/db/migrate/20081210021333_add_timestamps_to_users.rb
+++ b/db/migrate/20081210021333_add_timestamps_to_users.rb
@@ -1,4 +1,4 @@
-class AddTimestampsToUsers < ActiveRecord::Migration
+class AddTimestampsToUsers < ActiveRecord::Migration[4.2]
   def self.up
     add_timestamps :users
   end
diff --git a/db/migrate/20081215012843_change_user_login_string_limit.rb b/db/migrate/20081215012843_change_user_login_string_limit.rb
--- a/db/migrate/20081215012843_change_user_login_string_limit.rb
+++ b/db/migrate/20081215012843_change_user_login_string_limit.rb
@@ -1,4 +1,4 @@
-class ChangeUserLoginStringLimit < ActiveRecord::Migration
+class ChangeUserLoginStringLimit < ActiveRecord::Migration[4.2]
   def self.up
     execute "ALTER TABLE `users` CHANGE `login` `login` VARCHAR( 50 )"
   end
diff --git a/db/migrate/20090206145016_add_contest_flag_to_announcements.rb b/db/migrate/20090206145016_add_contest_flag_to_announcements.rb
--- a/db/migrate/20090206145016_add_contest_flag_to_announcements.rb
+++ b/db/migrate/20090206145016_add_contest_flag_to_announcements.rb
@@ -1,4 +1,4 @@
-class AddContestFlagToAnnouncements < ActiveRecord::Migration
+class AddContestFlagToAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, :contest_only, :boolean, :default => false
   end
diff --git a/db/migrate/20090416235658_add_common_ext_to_languages.rb b/db/migrate/20090416235658_add_common_ext_to_languages.rb
--- a/db/migrate/20090416235658_add_common_ext_to_languages.rb
+++ b/db/migrate/20090416235658_add_common_ext_to_languages.rb
@@ -1,4 +1,4 @@
-class AddCommonExtToLanguages < ActiveRecord::Migration
+class AddCommonExtToLanguages < ActiveRecord::Migration[4.2]
   def self.up
     # language.common_ext is a comma-separated list of common file
     # extensions.
diff --git a/db/migrate/20090426131044_add_terminated_to_grader_processes.rb b/db/migrate/20090426131044_add_terminated_to_grader_processes.rb
--- a/db/migrate/20090426131044_add_terminated_to_grader_processes.rb
+++ b/db/migrate/20090426131044_add_terminated_to_grader_processes.rb
@@ -1,4 +1,4 @@
-class AddTerminatedToGraderProcesses < ActiveRecord::Migration
+class AddTerminatedToGraderProcesses < ActiveRecord::Migration[4.2]
   def self.up
     add_column :grader_processes, :terminated, :boolean
   end
diff --git a/db/migrate/20090815171610_add_title_to_announcements.rb b/db/migrate/20090815171610_add_title_to_announcements.rb
--- a/db/migrate/20090815171610_add_title_to_announcements.rb
+++ b/db/migrate/20090815171610_add_title_to_announcements.rb
@@ -1,4 +1,4 @@
-class AddTitleToAnnouncements < ActiveRecord::Migration
+class AddTitleToAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, :title, :string
   end
diff --git a/db/migrate/20100113094740_create_test_pairs.rb b/db/migrate/20100113094740_create_test_pairs.rb
--- a/db/migrate/20100113094740_create_test_pairs.rb
+++ b/db/migrate/20100113094740_create_test_pairs.rb
@@ -1,6 +1,6 @@
-class CreateTestPairs < ActiveRecord::Migration
+class CreateTestPairs < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :test_pairs do |t|
+    create_table :test_pairs, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :problem_id
       t.text :input
       t.text :solution
diff --git a/db/migrate/20100124040107_add_description_to_config.rb b/db/migrate/20100124040107_add_description_to_config.rb
--- a/db/migrate/20100124040107_add_description_to_config.rb
+++ b/db/migrate/20100124040107_add_description_to_config.rb
@@ -1,4 +1,4 @@
-class AddDescriptionToConfig < ActiveRecord::Migration
+class AddDescriptionToConfig < ActiveRecord::Migration[4.2]
   def self.up
     add_column :configurations, :description, :text
   end
diff --git a/db/migrate/20100124054458_create_user_contest_stats.rb b/db/migrate/20100124054458_create_user_contest_stats.rb
--- a/db/migrate/20100124054458_create_user_contest_stats.rb
+++ b/db/migrate/20100124054458_create_user_contest_stats.rb
@@ -1,6 +1,6 @@
-class CreateUserContestStats < ActiveRecord::Migration
+class CreateUserContestStats < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :user_contest_stats do |t|
+    create_table :user_contest_stats, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :user_id
       t.timestamp :started_at
 
diff --git a/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb b/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb
--- a/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb
+++ b/db/migrate/20100129041917_change_input_solution_field_limit_in_test_pair.rb
@@ -1,4 +1,4 @@
-class ChangeInputSolutionFieldLimitInTestPair < ActiveRecord::Migration
+class ChangeInputSolutionFieldLimitInTestPair < ActiveRecord::Migration[4.2]
   def self.up
     change_column :test_pairs, :input, :text, :limit => 1.megabytes
     change_column :test_pairs, :solution, :text, :limit => 1.megabytes
diff --git a/db/migrate/20100216105730_create_contests.rb b/db/migrate/20100216105730_create_contests.rb
--- a/db/migrate/20100216105730_create_contests.rb
+++ b/db/migrate/20100216105730_create_contests.rb
@@ -1,6 +1,6 @@
-class CreateContests < ActiveRecord::Migration
+class CreateContests < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :contests do |t|
+    create_table :contests, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :title
       t.boolean :enabled
 
diff --git a/db/migrate/20100216162324_create_contests_users_join_table.rb b/db/migrate/20100216162324_create_contests_users_join_table.rb
--- a/db/migrate/20100216162324_create_contests_users_join_table.rb
+++ b/db/migrate/20100216162324_create_contests_users_join_table.rb
@@ -1,6 +1,6 @@
-class CreateContestsUsersJoinTable < ActiveRecord::Migration
+class CreateContestsUsersJoinTable < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :contests_users, :id => false do |t|
+    create_table :contests_users, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :contest_id
       t.integer :user_id
     end
diff --git a/db/migrate/20100216162940_create_contests_problems_join_table.rb b/db/migrate/20100216162940_create_contests_problems_join_table.rb
--- a/db/migrate/20100216162940_create_contests_problems_join_table.rb
+++ b/db/migrate/20100216162940_create_contests_problems_join_table.rb
@@ -1,6 +1,6 @@
-class CreateContestsProblemsJoinTable < ActiveRecord::Migration
+class CreateContestsProblemsJoinTable < ActiveRecord::Migration[4.2]
   def self.up
-    create_table :contests_problems, :id => false do |t|
+    create_table :contests_problems, :id => false, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :contest_id
       t.integer :problem_id
     end
diff --git a/db/migrate/20100219014840_add_description_filename_to_problems.rb b/db/migrate/20100219014840_add_description_filename_to_problems.rb
--- a/db/migrate/20100219014840_add_description_filename_to_problems.rb
+++ b/db/migrate/20100219014840_add_description_filename_to_problems.rb
@@ -1,4 +1,4 @@
-class AddDescriptionFilenameToProblems < ActiveRecord::Migration
+class AddDescriptionFilenameToProblems < ActiveRecord::Migration[4.2]
   def self.up
     add_column :problems, :description_filename, :string
   end
diff --git a/db/migrate/20100303095700_add_name_to_contests.rb b/db/migrate/20100303095700_add_name_to_contests.rb
--- a/db/migrate/20100303095700_add_name_to_contests.rb
+++ b/db/migrate/20100303095700_add_name_to_contests.rb
@@ -1,4 +1,4 @@
-class AddNameToContests < ActiveRecord::Migration
+class AddNameToContests < ActiveRecord::Migration[4.2]
   def self.up
     add_column :contests, :name, :string
   end    
diff --git a/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb b/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb
--- a/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb
+++ b/db/migrate/20100328123325_add_forced_logout_to_user_contest_stat.rb
@@ -1,4 +1,4 @@
-class AddForcedLogoutToUserContestStat < ActiveRecord::Migration
+class AddForcedLogoutToUserContestStat < ActiveRecord::Migration[4.2]
   def self.up
     add_column :user_contest_stats, :forced_logout, :boolean
   end
diff --git a/db/migrate/20100506163112_add_notes_to_announcements.rb b/db/migrate/20100506163112_add_notes_to_announcements.rb
--- a/db/migrate/20100506163112_add_notes_to_announcements.rb
+++ b/db/migrate/20100506163112_add_notes_to_announcements.rb
@@ -1,4 +1,4 @@
-class AddNotesToAnnouncements < ActiveRecord::Migration
+class AddNotesToAnnouncements < ActiveRecord::Migration[4.2]
   def self.up
     add_column :announcements, :notes, :string
   end
diff --git a/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb b/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb
--- a/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb
+++ b/db/migrate/20121001033508_rename_configurations_to_grader_configurations.rb
@@ -1,4 +1,4 @@
-class RenameConfigurationsToGraderConfigurations < ActiveRecord::Migration
+class RenameConfigurationsToGraderConfigurations < ActiveRecord::Migration[4.2]
   def change
     rename_table 'configurations', 'grader_configurations'
   end
diff --git a/db/migrate/20140823031747_add_more_detail_to_submission.rb b/db/migrate/20140823031747_add_more_detail_to_submission.rb
--- a/db/migrate/20140823031747_add_more_detail_to_submission.rb
+++ b/db/migrate/20140823031747_add_more_detail_to_submission.rb
@@ -1,4 +1,4 @@
-class AddMoreDetailToSubmission < ActiveRecord::Migration
+class AddMoreDetailToSubmission < ActiveRecord::Migration[4.2]
   def change
     add_column :submissions, :max_runtime, :float
     add_column :submissions, :peak_memory, :integer
diff --git a/db/migrate/20140826095949_create_logins.rb b/db/migrate/20140826095949_create_logins.rb
--- a/db/migrate/20140826095949_create_logins.rb
+++ b/db/migrate/20140826095949_create_logins.rb
@@ -1,6 +1,6 @@
-class CreateLogins < ActiveRecord::Migration
+class CreateLogins < ActiveRecord::Migration[4.2]
   def change
-    create_table :logins do |t|
+    create_table :logins, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :user_id
       t.string :ip_address
 
diff --git a/db/migrate/20140913060729_add_section_to_users.rb b/db/migrate/20140913060729_add_section_to_users.rb
--- a/db/migrate/20140913060729_add_section_to_users.rb
+++ b/db/migrate/20140913060729_add_section_to_users.rb
@@ -1,4 +1,4 @@
-class AddSectionToUsers < ActiveRecord::Migration
+class AddSectionToUsers < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :section, :string
   end
diff --git a/db/migrate/20140917150629_add_ip_to_submissions.rb b/db/migrate/20140917150629_add_ip_to_submissions.rb
--- a/db/migrate/20140917150629_add_ip_to_submissions.rb
+++ b/db/migrate/20140917150629_add_ip_to_submissions.rb
@@ -1,4 +1,4 @@
-class AddIpToSubmissions < ActiveRecord::Migration
+class AddIpToSubmissions < ActiveRecord::Migration[4.2]
   def change
     add_column :submissions, :ip_address, :string
   end
diff --git a/db/migrate/20150203153534_add_more_to_users.rb b/db/migrate/20150203153534_add_more_to_users.rb
--- a/db/migrate/20150203153534_add_more_to_users.rb
+++ b/db/migrate/20150203153534_add_more_to_users.rb
@@ -1,4 +1,4 @@
-class AddMoreToUsers < ActiveRecord::Migration
+class AddMoreToUsers < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :enabled, :boolean, default: 1
     add_column :users, :remark, :string
diff --git a/db/migrate/20150503164846_change_userid_on_login.rb b/db/migrate/20150503164846_change_userid_on_login.rb
--- a/db/migrate/20150503164846_change_userid_on_login.rb
+++ b/db/migrate/20150503164846_change_userid_on_login.rb
@@ -1,4 +1,4 @@
-class ChangeUseridOnLogin < ActiveRecord::Migration
+class ChangeUseridOnLogin < ActiveRecord::Migration[4.2]
   def up
     change_column :logins, :user_id, :integer
   end
diff --git a/db/migrate/20150827131927_create_submission_view_logs.rb b/db/migrate/20150827131927_create_submission_view_logs.rb
--- a/db/migrate/20150827131927_create_submission_view_logs.rb
+++ b/db/migrate/20150827131927_create_submission_view_logs.rb
@@ -1,6 +1,6 @@
-class CreateSubmissionViewLogs < ActiveRecord::Migration
+class CreateSubmissionViewLogs < ActiveRecord::Migration[4.2]
   def change
-    create_table :submission_view_logs do |t|
+    create_table :submission_view_logs, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.integer :user_id
       t.integer :submission_id
 
diff --git a/db/migrate/20150827133841_add_last_ip_to_user.rb b/db/migrate/20150827133841_add_last_ip_to_user.rb
--- a/db/migrate/20150827133841_add_last_ip_to_user.rb
+++ b/db/migrate/20150827133841_add_last_ip_to_user.rb
@@ -1,4 +1,4 @@
-class AddLastIpToUser < ActiveRecord::Migration
+class AddLastIpToUser < ActiveRecord::Migration[4.2]
   def change
     add_column :users, :last_ip, :string
   end
diff --git a/db/migrate/20150914090545_create_heart_beats.rb b/db/migrate/20150914090545_create_heart_beats.rb
--- a/db/migrate/20150914090545_create_heart_beats.rb
+++ b/db/migrate/20150914090545_create_heart_beats.rb
@@ -1,6 +1,6 @@
-class CreateHeartBeats < ActiveRecord::Migration
+class CreateHeartBeats < ActiveRecord::Migration[4.2]
   def change
-    create_table :heart_beats do |t|
+    create_table :heart_beats, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.column 'user_id',:integer
       t.column 'ip_address',:string
 
diff --git a/db/migrate/20150914155101_add_status_to_heart_beat.rb b/db/migrate/20150914155101_add_status_to_heart_beat.rb
--- a/db/migrate/20150914155101_add_status_to_heart_beat.rb
+++ b/db/migrate/20150914155101_add_status_to_heart_beat.rb
@@ -1,4 +1,4 @@
-class AddStatusToHeartBeat < ActiveRecord::Migration
+class AddStatusToHeartBeat < ActiveRecord::Migration[4.2]
   def change
     add_column :heart_beats, :status, :string
   end
diff --git a/db/migrate/20150914223258_add_more_config.rb b/db/migrate/20150914223258_add_more_config.rb
--- a/db/migrate/20150914223258_add_more_config.rb
+++ b/db/migrate/20150914223258_add_more_config.rb
@@ -1,4 +1,4 @@
-class AddMoreConfig < ActiveRecord::Migration
+class AddMoreConfig < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.bypass_agreement', value_type: 'boolean', value:'true', description:'When false, a check box to accept license agreement appear at login and the user must click accept'
   end
diff --git a/db/migrate/20150916054105_update_heart_beat.rb b/db/migrate/20150916054105_update_heart_beat.rb
--- a/db/migrate/20150916054105_update_heart_beat.rb
+++ b/db/migrate/20150916054105_update_heart_beat.rb
@@ -1,4 +1,4 @@
-class UpdateHeartBeat < ActiveRecord::Migration
+class UpdateHeartBeat < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.heartbeat_response', value_type: 'string', value:'OK', description:'Heart beat response text'
     add_index :heart_beats, :updated_at
diff --git a/db/migrate/20161008050135_modify_grader_process.rb b/db/migrate/20161008050135_modify_grader_process.rb
--- a/db/migrate/20161008050135_modify_grader_process.rb
+++ b/db/migrate/20161008050135_modify_grader_process.rb
@@ -1,4 +1,4 @@
-class ModifyGraderProcess < ActiveRecord::Migration
+class ModifyGraderProcess < ActiveRecord::Migration[4.2]
   def up
     change_column :grader_processes, :host, :string
   end
diff --git a/db/migrate/20161014091417_create_testcases.rb b/db/migrate/20161014091417_create_testcases.rb
--- a/db/migrate/20161014091417_create_testcases.rb
+++ b/db/migrate/20161014091417_create_testcases.rb
@@ -1,6 +1,6 @@
-class CreateTestcases < ActiveRecord::Migration
+class CreateTestcases < ActiveRecord::Migration[4.2]
   def change
-    create_table :testcases do |t|
+    create_table :testcases, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.references :problem
       t.integer :num
       t.integer :group
diff --git a/db/migrate/20161031063337_add_config_view_test.rb b/db/migrate/20161031063337_add_config_view_test.rb
--- a/db/migrate/20161031063337_add_config_view_test.rb
+++ b/db/migrate/20161031063337_add_config_view_test.rb
@@ -1,4 +1,4 @@
-class AddConfigViewTest < ActiveRecord::Migration
+class AddConfigViewTest < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.view_testcase', value_type: 'boolean', value:'true', description:'When true, any user can view/download test data'
     #uglily and dirtily and shamelessly check other config and inifialize
diff --git a/db/migrate/20170123162543_change_testcase_size.rb b/db/migrate/20170123162543_change_testcase_size.rb
--- a/db/migrate/20170123162543_change_testcase_size.rb
+++ b/db/migrate/20170123162543_change_testcase_size.rb
@@ -1,4 +1,4 @@
-class ChangeTestcaseSize < ActiveRecord::Migration
+class ChangeTestcaseSize < ActiveRecord::Migration[4.2]
   def change
     change_column :testcases, :input, :text, :limit => 4294967295
     change_column :testcases, :sol, :text, :limit => 4294967295
diff --git a/db/migrate/20170124024527_add_view_testcase_to_problem.rb b/db/migrate/20170124024527_add_view_testcase_to_problem.rb
--- a/db/migrate/20170124024527_add_view_testcase_to_problem.rb
+++ b/db/migrate/20170124024527_add_view_testcase_to_problem.rb
@@ -1,4 +1,4 @@
-class AddViewTestcaseToProblem < ActiveRecord::Migration
+class AddViewTestcaseToProblem < ActiveRecord::Migration[4.2]
   def change
     add_column :problems, :view_testcase, :bool
   end
diff --git a/db/migrate/20170310110146_add_index_to_task.rb b/db/migrate/20170310110146_add_index_to_task.rb
--- a/db/migrate/20170310110146_add_index_to_task.rb
+++ b/db/migrate/20170310110146_add_index_to_task.rb
@@ -1,4 +1,4 @@
-class AddIndexToTask < ActiveRecord::Migration
+class AddIndexToTask < ActiveRecord::Migration[4.2]
   def change
     add_index :tasks, :submission_id
   end
diff --git a/db/migrate/20170427070345_add_heart_beat_full.rb b/db/migrate/20170427070345_add_heart_beat_full.rb
--- a/db/migrate/20170427070345_add_heart_beat_full.rb
+++ b/db/migrate/20170427070345_add_heart_beat_full.rb
@@ -1,4 +1,4 @@
-class AddHeartBeatFull < ActiveRecord::Migration
+class AddHeartBeatFull < ActiveRecord::Migration[4.2]
   def up
     GraderConfiguration.create key: 'right.heartbeat_response_full', value_type: 'string', value:'RESTART', description:'Heart beat response text when user got full score (set this value to the empty string to disable this feature)'
   end
diff --git a/db/migrate/20170911091143_create_groups.rb b/db/migrate/20170911091143_create_groups.rb
--- a/db/migrate/20170911091143_create_groups.rb
+++ b/db/migrate/20170911091143_create_groups.rb
@@ -1,17 +1,17 @@
-class CreateGroups < ActiveRecord::Migration
+class CreateGroups < ActiveRecord::Migration[4.2]
 
   def change
-    create_table :groups do |t|
+    create_table :groups, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :name
       t.string :description
     end
 
-    create_join_table :groups, :users do |t|
+    create_join_table :groups, :users, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       # t.index [:group_id, :user_id]
       t.index [:user_id, :group_id]
     end
 
-    create_join_table :problems, :groups do |t|
+    create_join_table :problems, :groups, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       # t.index [:problem_id, :group_id]
       t.index [:group_id, :problem_id]
     end
diff --git a/db/migrate/20170914150545_create_tags.rb b/db/migrate/20170914150545_create_tags.rb
--- a/db/migrate/20170914150545_create_tags.rb
+++ b/db/migrate/20170914150545_create_tags.rb
@@ -1,6 +1,6 @@
-class CreateTags < ActiveRecord::Migration
+class CreateTags < ActiveRecord::Migration[4.2]
   def change
-    create_table :tags do |t|
+    create_table :tags, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.string :name, null: false
       t.text :description
       t.boolean :public
diff --git a/db/migrate/20170914150742_create_problem_tags.rb b/db/migrate/20170914150742_create_problem_tags.rb
--- a/db/migrate/20170914150742_create_problem_tags.rb
+++ b/db/migrate/20170914150742_create_problem_tags.rb
@@ -1,6 +1,6 @@
-class CreateProblemTags < ActiveRecord::Migration
+class CreateProblemTags < ActiveRecord::Migration[4.2]
   def change
-    create_table :problems_tags do |t|
+    create_table :problems_tags, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci" do |t|
       t.references :problem, index: true, foreign_key: true
       t.references :tag, index: true, foreign_key: true
 
diff --git a/script/about b/script/about
deleted file mode 100755
--- a/script/about
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/about'
\ No newline at end of file
diff --git a/script/autospec b/script/autospec
deleted file mode 100755
--- a/script/autospec
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/usr/bin/env ruby
-gem 'test-unit', '1.2.3' if RUBY_VERSION.to_f >= 1.9
-ENV['RSPEC'] = 'true'     # allows autotest to discover rspec
-ENV['AUTOTEST'] = 'true'  # allows autotest to run w/ color on linux
-system((RUBY_PLATFORM =~ /mswin|mingw/ ? 'autotest.bat' : 'autotest'), *ARGV) ||
-  $stderr.puts("Unable to find autotest.  Please install ZenTest or fix your PATH")
diff --git a/script/breakpointer b/script/breakpointer
deleted file mode 100755
--- a/script/breakpointer
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/breakpointer'
\ No newline at end of file
diff --git a/script/console b/script/console
deleted file mode 100755
--- a/script/console
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/console'
\ No newline at end of file
diff --git a/script/dbconsole b/script/dbconsole
deleted file mode 100755
--- a/script/dbconsole
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/dbconsole'
diff --git a/script/destroy b/script/destroy
deleted file mode 100755
--- a/script/destroy
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/destroy'
\ No newline at end of file
diff --git a/script/generate b/script/generate
deleted file mode 100755
--- a/script/generate
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/generate'
\ No newline at end of file
diff --git a/script/performance/benchmarker b/script/performance/benchmarker
deleted file mode 100755
--- a/script/performance/benchmarker
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../../config/boot'
-require 'commands/performance/benchmarker'
diff --git a/script/performance/profiler b/script/performance/profiler
deleted file mode 100755
--- a/script/performance/profiler
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../../config/boot'
-require 'commands/performance/profiler'
diff --git a/script/performance/request b/script/performance/request
deleted file mode 100755
--- a/script/performance/request
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../../config/boot'
-require 'commands/performance/request'
diff --git a/script/plugin b/script/plugin
deleted file mode 100755
--- a/script/plugin
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/plugin'
\ No newline at end of file
diff --git a/script/process/inspector b/script/process/inspector
deleted file mode 100755
--- a/script/process/inspector
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../../config/boot'
-require 'commands/process/inspector'
diff --git a/script/process/reaper b/script/process/reaper
deleted file mode 100755
--- a/script/process/reaper
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../../config/boot'
-require 'commands/process/reaper'
diff --git a/script/process/spawner b/script/process/spawner
deleted file mode 100755
--- a/script/process/spawner
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../../config/boot'
-require 'commands/process/spawner'
diff --git a/script/rails b/script/rails
deleted file mode 100755
--- a/script/rails
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/usr/bin/env ruby
-# This command will automatically be run when you run "rails" with Rails 3 gems installed from the root of your application.
-
-APP_PATH = File.expand_path('../../config/application',  __FILE__)
-require File.expand_path('../../config/boot',  __FILE__)
-require 'rails/commands'
diff --git a/script/runner b/script/runner
deleted file mode 100755
--- a/script/runner
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/runner'
\ No newline at end of file
diff --git a/script/score_subtask.rb b/script/score_subtask.rb
new file mode 100644
--- /dev/null
+++ b/script/score_subtask.rb
@@ -0,0 +1,89 @@
+def display_manual
+  puts <<-USAGE
+    subtask_score problem last_submision_id sub1_score,sub2_score,sub3_score,....
+    example:
+      rails runner subtask_score.rb o64_may26_train 102983 10,15,18,18,39
+  USAGE
+end
+
+def process_options
+  res = {}
+  if ARGV.length == 0
+    display_manual
+    exit(1)
+  end
+
+  res[:prob] = ARGV[0]
+  res[:last_sub_id] = ARGV[1].to_i
+  res[:score] = ARGV[2].split(',').map {|x| x.to_i}
+  return res
+end
+
+def process_subtask(st)
+  return true if /^P+$/.match(st)
+  return false
+end
+
+def process_comment(st)
+  res = []
+  loop do
+    break if st.length == 0
+    if st[0] == '['
+      #subtask
+      subtask = st.slice!(0..(st.index(']')))
+      res << process_subtask(subtask[1..-2])
+    else #not subtask
+      res << process_subtask(st[0])
+      st.slice!(0)
+    end
+  end
+  return res
+end
+
+options = process_options
+scoring = options[:score]
+puts "doing problem #{options[:prob]}"
+puts "  consider only submission with id not more than #{options[:last_sub_id]}"
+scoring.each.with_index { |x,i| puts "  subtask#{i}: #{x}" }
+
+res = {}
+
+p = Problem.where(name: options[:prob]).first
+unless p
+  puts "Problem #{options[:prob]} not found"
+  exit(2)
+end
+
+p.submissions.where('id <= ?',options[:last_sub_id]).order(:id).each do |sub|
+  unless sub.graded_at
+    puts "skip ungraded submission #{sub.id}"
+    next
+  end
+  if sub.grader_comment == "compilation error"
+    puts "skip uncompilable submission #{sub.id}"
+    next
+  end
+
+  comment = sub.grader_comment.clone
+  comment_result = process_comment(comment)
+  if comment_result.length != scoring.length
+    puts "ERROR!!! subtask of submission #{sub.id} does not match scoring input"
+  end
+
+  puts "processing submission #{sub.id} with comment = #{sub.grader_comment} result is #{comment_result}"
+  current = res[sub.user.login] || [false] * scoring.length
+  current.each.with_index do |x,i|
+    if !x && comment_result[i]
+      puts "  user #{sub.user.login} just got subtask #{i+1} from this submission"
+      current[i] = true
+    end
+  end
+  res[sub.user.login] = current
+end
+
+puts "----summary-----"
+res.each do |u,r|
+  score = scoring.clone
+  r.each.with_index { |pass,i| score[i] = 0 unless pass }
+  puts "#{u} #{score.sum} [#{score.join(',')}]"
+end
diff --git a/script/server b/script/server
deleted file mode 100755
--- a/script/server
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env ruby
-require File.dirname(__FILE__) + '/../config/boot'
-require 'commands/server'
\ No newline at end of file
diff --git a/script/spec b/script/spec
deleted file mode 100755
--- a/script/spec
+++ /dev/null
@@ -1,10 +0,0 @@
-#!/usr/bin/env ruby
-if ARGV.any? {|arg| %w[--drb -X --generate-options -G --help -h --version -v].include?(arg)}
-  require 'rubygems' unless ENV['NO_RUBYGEMS']
-else
-  gem 'test-unit', '1.2.3' if RUBY_VERSION.to_f >= 1.9
-  ENV["RAILS_ENV"] ||= 'test'
-  require File.expand_path(File.dirname(__FILE__) + "/../config/environment") unless defined?(RAILS_ROOT)
-end
-require 'spec/autorun'
-exit ::Spec::Runner::CommandLine.run
diff --git a/script/spec_server b/script/spec_server
deleted file mode 100755
--- a/script/spec_server
+++ /dev/null
@@ -1,102 +0,0 @@
-#!/usr/bin/env ruby
-$LOAD_PATH.unshift File.dirname(__FILE__) + '/../../rspec/lib' # For svn
-$LOAD_PATH.unshift File.dirname(__FILE__) + '/../vendor/plugins/rspec/lib' # For rspec installed as plugin
-require 'rubygems'
-require 'drb/drb'
-require 'rbconfig'
-require 'spec'
-require 'optparse'
-
-# This is based on Florian Weber's TDDMate
-module Spec
-  module Runner
-    class RailsSpecServer
-      def run(argv, stderr, stdout)
-        $stdout = stdout
-        $stderr = stderr
-
-        base = ActiveRecord::Base
-        def base.clear_reloadable_connections!
-          active_connections.each do |name, conn|
-            if conn.requires_reloading?
-              conn.disconnect!
-              active_connections.delete(name)
-            end
-          end
-        end        
-
-        if ActionController.const_defined?(:Dispatcher)
-          dispatcher = ::ActionController::Dispatcher.new($stdout)
-          dispatcher.cleanup_application(true)
-        elsif ::Dispatcher.respond_to?(:reset_application!)
-          ::Dispatcher.reset_application!
-        else
-          raise "Application reloading failed"
-        end
-        ::Dependencies.mechanism = :load
-        require_dependency('application.rb') unless Object.const_defined?(:ApplicationController)
-        load File.dirname(__FILE__) + '/../spec/spec_helper.rb'
-
-        ::Spec::Runner::CommandLine.run(
-          ::Spec::Runner::OptionParser.parse(
-            argv,
-            $stderr,
-            $stdout
-          )
-        )
-      end
-    end
-  end
-end
-puts "Loading Rails environment"
-
-ENV["RAILS_ENV"] = "test"
-require File.expand_path(File.dirname(__FILE__) + "/../config/environment")
-require 'dispatcher'
-
-def restart_test_server
-  puts "restarting"
-  config       = ::Config::CONFIG
-  ruby         = File::join(config['bindir'], config['ruby_install_name']) + config['EXEEXT']
-  command_line = [ruby, $0, ARGV].flatten.join(' ')
-  exec(command_line)
-end
-
-def daemonize(pid_file = nil)
-  return yield if $DEBUG
-  pid = Process.fork{
-    Process.setsid
-    Dir.chdir(RAILS_ROOT)
-    trap("SIGINT"){ exit! 0 }
-    trap("SIGTERM"){ exit! 0 }
-    trap("SIGHUP"){ restart_test_server }
-    File.open("/dev/null"){|f|
-      STDERR.reopen f
-      STDIN.reopen  f
-      STDOUT.reopen f
-    }
-    yield
-  }
-  puts "spec_server launched. (PID: %d)" % pid
-  File.open(pid_file,"w"){|f| f.puts pid } if pid_file
-  exit! 0
-end
-
-options = Hash.new
-opts = OptionParser.new
-opts.on("-d", "--daemon"){|v| options[:daemon] = true }
-opts.on("-p", "--pid PIDFILE"){|v| options[:pid] = v }
-opts.parse!(ARGV)
-
-puts "Ready"
-exec_server = lambda {
-  trap("USR2") { restart_test_server } if Signal.list.has_key?("USR2")
-  DRb.start_service("druby://localhost:8989", Spec::Runner::RailsSpecServer.new)
-  DRb.thread.join
-}
-
-if options[:daemon]
-  daemonize(options[:pid], &exec_server)
-else
-  exec_server.call
-end
diff --git a/spec/models/testcases_spec.rb b/spec/models/testcases_spec.rb
deleted file mode 100644
--- a/spec/models/testcases_spec.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'spec_helper'
-
-describe Testcases do
-  pending "add some examples to (or delete) #{__FILE__}"
-end
diff --git a/stories/all.rb b/stories/all.rb
deleted file mode 100644
--- a/stories/all.rb
+++ /dev/null
@@ -1,4 +0,0 @@
-dir = File.dirname(__FILE__)
-Dir[File.expand_path("#{dir}/**/*.rb")].uniq.each do |file|
-  require file
-end
\ No newline at end of file
diff --git a/stories/helper.rb b/stories/helper.rb
deleted file mode 100644
--- a/stories/helper.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-ENV["RAILS_ENV"] = "test"
-require File.expand_path(File.dirname(__FILE__) + "/../config/environment")
-require 'spec/rails/story_adapter'
\ No newline at end of file