diff --git a/.rubocop.yml b/.rubocop.yml
index 6bdcbfc3..e7819c17 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -19,3 +19,6 @@ Metrics/AbcSize:
 
 Style/Documentation:
   Enabled: false
+
+Style/EmptyMethod:
+  EnforcedStyle: expanded
diff --git a/Gemfile b/Gemfile
index 56ee0bd2..cf3eecb1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,7 +9,6 @@ gem 'aws-sdk'
 gem 'best_in_place'
 gem 'delayed_job'
 gem 'delayed_job_active_record'
-gem 'sucker_punch'
 gem 'devise'
 gem 'doorkeeper'
 gem 'dotenv-rails'
@@ -20,6 +19,7 @@ gem 'kaminari'
 gem 'mailboxer'
 gem 'paperclip'
 gem 'pg'
+gem 'puma'
 gem 'pundit'
 gem 'pundit_extra'
 gem 'rack-attack'
@@ -27,7 +27,7 @@ gem 'rack-cors'
 gem 'redis'
 gem 'slack-notifier'
 gem 'snorlax'
-gem 'puma'
+gem 'sucker_punch'
 
 # asset stuff
 gem 'jquery-rails'
@@ -36,12 +36,12 @@ gem 'sass-rails'
 gem 'uglifier'
 
 group :test do
+  gem 'brakeman', require: false
   gem 'factory_girl_rails'
   gem 'json-schema'
   gem 'rspec-rails'
   gem 'shoulda-matchers'
   gem 'simplecov', require: false
-  gem 'brakeman', require: false
 end
 
 group :development, :test do
@@ -49,6 +49,6 @@ group :development, :test do
   gem 'binding_of_caller'
   gem 'pry-byebug'
   gem 'pry-rails'
-  gem 'tunemygc'
   gem 'rubocop'
+  gem 'tunemygc'
 end
diff --git a/app/assets/config/manifest.js b/app/assets/config/manifest.js
index 72a7189c..41328039 100644
--- a/app/assets/config/manifest.js
+++ b/app/assets/config/manifest.js
@@ -1,3 +1,4 @@
+// eslint-disable spaced-comment
 // JS and CSS bundles
 //= link_directory ../javascripts .js
 //= link_directory ../stylesheets .css
diff --git a/app/assets/javascripts/application.js b/app/assets/javascripts/application.js
index 4483452c..529ab13e 100644
--- a/app/assets/javascripts/application.js
+++ b/app/assets/javascripts/application.js
@@ -1,4 +1,3 @@
-// eslint-disable spaced-comment
 // This is a manifest file that'll be compiled into application.js, which will include all the files
 // listed below.
 //
@@ -10,7 +9,8 @@
 //
 // WARNING: THE FIRST BLANK LINE MARKS THE END OF WHAT'S TO BE PROCESSED, ANY BLANK LINE SHOULD
 // GO AFTER THE REQUIRES BELOW.
-//  
+//
+/* eslint-disable spaced-comment */
 //= require jquery3
 //= require jquery-ui
 //= require jquery_ujs
@@ -19,3 +19,4 @@
 //= require ./webpacked/metamaps.bundle
 //= require ./Metamaps.ServerData
 //= require homepageVimeoFallback
+/* eslint-enable spaced-comment */
diff --git a/app/assets/javascripts/homepageVimeoFallback.js b/app/assets/javascripts/homepageVimeoFallback.js
index e4f5a67a..53c691eb 100644
--- a/app/assets/javascripts/homepageVimeoFallback.js
+++ b/app/assets/javascripts/homepageVimeoFallback.js
@@ -1,11 +1,11 @@
 /* global $ */
 
-$(document).ready(function () {
+$(document).ready(function() {
   if (window.location.pathname === '/') {
     $.ajax({
       type: 'GET',
       url: 'https://player.vimeo.com',
-      error: function (e) {
+      error: function(e) {
         $('.homeVideo').hide()
         $('.homeVideo').replaceWith($('<video/>', {
           poster: '/assets/metamaps-intro-poster.webp',
diff --git a/app/channels/application_cable/channel.rb b/app/channels/application_cable/channel.rb
index d6726972..51e3e936 100644
--- a/app/channels/application_cable/channel.rb
+++ b/app/channels/application_cable/channel.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module ApplicationCable
   class Channel < ActionCable::Channel::Base
   end
diff --git a/app/channels/map_channel.rb b/app/channels/map_channel.rb
index e7c10b45..9d072e10 100644
--- a/app/channels/map_channel.rb
+++ b/app/channels/map_channel.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 class MapChannel < ApplicationCable::Channel
   # Called when the consumer has successfully
   # become a subscriber of this channel.
diff --git a/app/controllers/access_controller.rb b/app/controllers/access_controller.rb
index 2441aa62..29b08b85 100644
--- a/app/controllers/access_controller.rb
+++ b/app/controllers/access_controller.rb
@@ -1,8 +1,10 @@
 # frozen_string_literal: true
 class AccessController < ApplicationController
-  before_action :require_user, only: [:access, :access_request, :approve_access, :approve_access_post,
+  before_action :require_user, only: [:access, :access_request,
+                                      :approve_access, :approve_access_post,
                                       :deny_access, :deny_access_post, :request_access]
-  before_action :set_map, only: [:access, :access_request, :approve_access, :approve_access_post,
+  before_action :set_map, only: [:access, :access_request,
+                                 :approve_access, :approve_access_post,
                                  :deny_access, :deny_access_post, :request_access]
   after_action :verify_authorized
 
diff --git a/app/controllers/api/v2/restful_controller.rb b/app/controllers/api/v2/restful_controller.rb
index 4d122bc8..68d6a63f 100644
--- a/app/controllers/api/v2/restful_controller.rb
+++ b/app/controllers/api/v2/restful_controller.rb
@@ -87,7 +87,7 @@ module Api
 
       def token_user
         token = params[:access_token]
-        access_token = Token.find_by_token(token)
+        access_token = Token.find_by(token: token)
         @token_user ||= access_token.user if access_token
       end
 
@@ -160,7 +160,7 @@ module Api
       def search_by_q(collection)
         table = resource_class.arel_table
         safe_query = "%#{params[:q].gsub(/[%_]/, '\\\\\0')}%"
-        search_column = -> (column) { table[column].matches(safe_query) }
+        search_column = ->(column) { table[column].matches(safe_query) }
 
         condition = searchable_columns.reduce(nil) do |prev, column|
           next search_column.call(column) if prev.nil?
diff --git a/app/controllers/hacks_controller.rb b/app/controllers/hacks_controller.rb
index 22df9cbb..d21d039f 100644
--- a/app/controllers/hacks_controller.rb
+++ b/app/controllers/hacks_controller.rb
@@ -5,7 +5,6 @@ class HacksController < ApplicationController
   include ActionView::Helpers::TextHelper # string truncate method
 
   # rate limited by rack-attack - currently 5r/s
-  # TODO: what else can we do to make get_with_redirects safer?
   def load_url_title
     authorize :Hack
     url = params[:url]
diff --git a/app/controllers/metacode_sets_controller.rb b/app/controllers/metacode_sets_controller.rb
index 8fec58cc..55b8e99a 100644
--- a/app/controllers/metacode_sets_controller.rb
+++ b/app/controllers/metacode_sets_controller.rb
@@ -55,8 +55,13 @@ class MetacodeSetsController < ApplicationController
         @metacodes.each do |m|
           InMetacodeSet.create(metacode_id: m, metacode_set_id: @metacode_set.id)
         end
-        format.html { redirect_to metacode_sets_url, notice: 'Metacode set was successfully created.' }
-        format.json { render json: @metacode_set, status: :created, location: metacode_sets_url }
+        format.html do
+          redirect_to metacode_sets_url,
+                      notice: 'Metacode set was successfully created.'
+        end
+        format.json do
+          render json: @metacode_set, status: :created, location: metacode_sets_url
+        end
       else
         format.html { render action: 'new' }
         format.json { render json: @metacode_set.errors, status: :unprocessable_entity }
@@ -73,20 +78,20 @@ class MetacodeSetsController < ApplicationController
       if @metacode_set.update_attributes(metacode_set_params)
 
         # build an array of the IDs of the metacodes currently in the set
-        @currentMetacodes = @metacode_set.metacodes.map { |m| m.id.to_s }
+        current_metacodes = @metacode_set.metacodes.map { |m| m.id.to_s }
         # get the list of desired metacodes for the set from the user input and build an array out of it
-        @newMetacodes = params[:metacodes][:value].split(',')
+        new_metacodes = params[:metacodes][:value].split(',')
 
         # remove the metacodes that were in it, but now aren't
-        @removedMetacodes = @currentMetacodes - @newMetacodes
-        @removedMetacodes.each do |m|
-          @inmetacodeset = InMetacodeSet.find_by_metacode_id_and_metacode_set_id(m, @metacode_set.id)
-          @inmetacodeset.destroy
+        removed_metacodes = current_metacodes - new_metacodes
+        removed_metacodes.each do |m|
+          inmetacodeset = InMetacodeSet.find_by(metacode_id: m, metacode_set_id: @metacode_set.id)
+          inmetacodeset.destroy
         end
 
         # add the new metacodes
-        @addedMetacodes = @newMetacodes - @currentMetacodes
-        @addedMetacodes.each do |m|
+        added_metacodes = new_metacodes - current_metacodes
+        added_metacodes.each do |m|
           InMetacodeSet.create(metacode_id: m, metacode_set_id: @metacode_set.id)
         end
 
diff --git a/app/controllers/search_controller.rb b/app/controllers/search_controller.rb
index c488c556..8edf0324 100644
--- a/app/controllers/search_controller.rb
+++ b/app/controllers/search_controller.rb
@@ -14,7 +14,8 @@ class SearchController < ApplicationController
     term = params[:term]
     user = params[:user] ? params[:user] : false
 
-    if term && !term.empty? && term.downcase[0..3] != 'map:' && term.downcase[0..6] != 'mapper:' && !term.casecmp('topic:').zero?
+    if term.present? && term.downcase[0..3] != 'map:' &&
+       term.downcase[0..6] != 'mapper:' && !term.casecmp('topic:').zero?
 
       # remove "topic:" if appended at beginning
       term = term[6..-1] if term.downcase[0..5] == 'topic:'
@@ -34,28 +35,28 @@ class SearchController < ApplicationController
       end
 
       # check whether there's a filter by metacode as part of the query
-      filterByMetacode = false
+      filter_by_metacode = false
       Metacode.all.each do |m|
-        lOne = m.name.length + 1
-        lTwo = m.name.length
+        length_one = m.name.length + 1
+        length_two = m.name.length
 
-        if term.downcase[0..lTwo] == m.name.downcase + ':'
-          term = term[lOne..-1]
-          filterByMetacode = m
+        if term.downcase[0..length_two] == m.name.downcase + ':'
+          term = term[length_one..-1]
+          filter_by_metacode = m
         end
       end
 
       search = '%' + term.downcase.strip + '%'
       builder = policy_scope(Topic)
 
-      if filterByMetacode
+      if filter_by_metacode
         if term == ''
           builder = builder.none
         else
           builder = builder.where('LOWER("name") like ? OR
                                    LOWER("desc") like ? OR
                                    LOWER("link") like ?', search, search, search)
-          builder = builder.where(metacode_id: filterByMetacode.id)
+          builder = builder.where(metacode_id: filter_by_metacode.id)
         end
       elsif desc
         builder = builder.where('LOWER("desc") like ?', search)
@@ -82,7 +83,8 @@ class SearchController < ApplicationController
     term = params[:term]
     user = params[:user] ? params[:user] : nil
 
-    if term && !term.empty? && term.downcase[0..5] != 'topic:' && term.downcase[0..6] != 'mapper:' && !term.casecmp('map:').zero?
+    if term.present? && term.downcase[0..5] != 'topic:' &&
+       term.downcase[0..6] != 'mapper:' && !term.casecmp('map:').zero?
 
       # remove "map:" if appended at beginning
       term = term[4..-1] if term.downcase[0..3] == 'map:'
@@ -115,7 +117,8 @@ class SearchController < ApplicationController
   # get /search/mappers?term=SOMETERM
   def mappers
     term = params[:term]
-    if term && !term.empty? && term.downcase[0..3] != 'map:' && term.downcase[0..5] != 'topic:' && !term.casecmp('mapper:').zero?
+    if term.present? && term.downcase[0..3] != 'map:' &&
+       term.downcase[0..5] != 'topic:' && !term.casecmp('mapper:').zero?
 
       # remove "mapper:" if appended at beginning
       term = term[7..-1] if term.downcase[0..6] == 'mapper:'
@@ -138,13 +141,15 @@ class SearchController < ApplicationController
     topic2id = params[:topic2id]
 
     if term && !term.empty?
-      @synapses = policy_scope(Synapse).where('LOWER("desc") like ?', '%' + term.downcase.strip + '%').order('"desc"')
+      @synapses = policy_scope(Synapse)
+                  .where('LOWER("desc") like ?', '%' + term.downcase.strip + '%')
+                  .order('"desc"')
 
       @synapses = @synapses.uniq(&:desc)
     elsif topic1id && !topic1id.empty?
-      @one = policy_scope(Synapse).where(topic1_id: topic1id, topic2_id: topic2id)
-      @two = policy_scope(Synapse).where(topic2_id: topic1id, topic1_id: topic2id)
-      @synapses = @one + @two
+      one = policy_scope(Synapse).where(topic1_id: topic1id, topic2_id: topic2id)
+      two = policy_scope(Synapse).where(topic2_id: topic1id, topic1_id: topic2id)
+      @synapses = one + two
       @synapses.sort! { |s1, s2| s1.desc <=> s2.desc }.to_a
     else
       skip_policy_scope
diff --git a/app/controllers/synapses_controller.rb b/app/controllers/synapses_controller.rb
index c3aed2bc..6c9807ac 100644
--- a/app/controllers/synapses_controller.rb
+++ b/app/controllers/synapses_controller.rb
@@ -71,6 +71,8 @@ class SynapsesController < ApplicationController
   private
 
   def synapse_params
-    params.require(:synapse).permit(:id, :desc, :category, :weight, :permission, :topic1_id, :topic2_id, :user_id)
+    params.require(:synapse).permit(
+      :id, :desc, :category, :weight, :permission, :topic1_id, :topic2_id, :user_id
+    )
   end
 end
diff --git a/app/controllers/topics_controller.rb b/app/controllers/topics_controller.rb
index b54cc4f5..1193dbee 100644
--- a/app/controllers/topics_controller.rb
+++ b/app/controllers/topics_controller.rb
@@ -11,16 +11,20 @@ class TopicsController < ApplicationController
   def autocomplete_topic
     term = params[:term]
     if term && !term.empty?
-      @topics = policy_scope(Topic).where('LOWER("name") like ?', term.downcase + '%').order('"name"')
-      @mapTopics = @topics.select { |t| t&.metacode&.name == 'Metamap' }
+      topics = policy_scope(Topic)
+               .where('LOWER("name") like ?', term.downcase + '%')
+               .order('"name"')
+      map_topics = topics.select { |t| t&.metacode&.name == 'Metamap' }
       # prioritize topics which point to maps, over maps
-      @exclude = @mapTopics.length.positive? ? @mapTopics.map(&:name) : ['']
-      @maps = policy_scope(Map).where('LOWER("name") like ? AND name NOT IN (?)', term.downcase + '%', @exclude).order('"name"')
+      exclude = map_topics.length.positive? ? map_topics.map(&:name) : ['']
+      maps = policy_scope(Map)
+             .where('LOWER("name") like ? AND name NOT IN (?)', term.downcase + '%', exclude)
+             .order('"name"')
     else
-      @topics = []
-      @maps = []
+      topics = []
+      maps = []
     end
-    @all = @topics.to_a.concat(@maps.to_a).sort_by(&:name)
+    @all = topics.to_a.concat(maps.to_a).sort_by(&:name)
 
     render json: autocomplete_array_json(@all).to_json
   end
@@ -70,13 +74,13 @@ class TopicsController < ApplicationController
     @topic = Topic.find(params[:id])
     authorize @topic
 
-    topicsAlreadyHas = params[:network] ? params[:network].split(',').map(&:to_i) : []
+    topics_already_has = params[:network] ? params[:network].split(',').map(&:to_i) : []
 
     alltopics = policy_scope(Topic.relatives(@topic.id, current_user)).to_a
-    alltopics.delete_if { |topic| topic.metacode_id != params[:metacode].to_i } if params[:metacode].present?
-    alltopics.delete_if do |topic|
-      !topicsAlreadyHas.index(topic.id).nil?
+    if params[:metacode].present?
+      alltopics.delete_if { |topic| topic.metacode_id != params[:metacode].to_i }
     end
+    alltopics.delete_if { |topic| !topics_already_has.index(topic.id).nil? }
 
     @json = Hash.new(0)
     alltopics.each do |t|
@@ -93,12 +97,14 @@ class TopicsController < ApplicationController
     @topic = Topic.find(params[:id])
     authorize @topic
 
-    topicsAlreadyHas = params[:network] ? params[:network].split(',').map(&:to_i) : []
+    topics_already_has = params[:network] ? params[:network].split(',').map(&:to_i) : []
 
     alltopics = policy_scope(Topic.relatives(@topic.id, current_user)).to_a
-    alltopics.delete_if { |topic| topic.metacode_id != params[:metacode].to_i } if params[:metacode].present?
+    if params[:metacode].present?
+      alltopics.delete_if { |topic| topic.metacode_id != params[:metacode].to_i }
+    end
     alltopics.delete_if do |topic|
-      !topicsAlreadyHas.index(topic.id.to_s).nil?
+      !topics_already_has.index(topic.id.to_s).nil?
     end
 
     # find synapses between topics in alltopics array
@@ -108,9 +114,9 @@ class TopicsController < ApplicationController
       !synapse_ids.index(synapse.id).nil?
     end
 
-    creatorsAlreadyHas = params[:creators] ? params[:creators].split(',').map(&:to_i) : []
+    creators_already_has = params[:creators] ? params[:creators].split(',').map(&:to_i) : []
     allcreators = (alltopics.map(&:user) + allsynapses.map(&:user)).uniq.delete_if do |user|
-      !creatorsAlreadyHas.index(user.id).nil?
+      !creators_already_has.index(user.id).nil?
     end
 
     @json = {}
diff --git a/app/controllers/users/passwords_controller.rb b/app/controllers/users/passwords_controller.rb
index 8a66e820..8e8bccfc 100644
--- a/app/controllers/users/passwords_controller.rb
+++ b/app/controllers/users/passwords_controller.rb
@@ -1,12 +1,14 @@
 # frozen_string_literal: true
-class Users::PasswordsController < Devise::PasswordsController
-  protected
+module Users
+  class PasswordsController < Devise::PasswordsController
+    protected
 
-  def after_resetting_password_path_for(resource)
-    signed_in_root_path(resource)
-  end
+    def after_resetting_password_path_for(resource)
+      signed_in_root_path(resource)
+    end
 
-  def after_sending_reset_password_instructions_path_for(_resource_name)
-    sign_in_path if is_navigational_format?
+    def after_sending_reset_password_instructions_path_for(_resource_name)
+      sign_in_path if is_navigational_format?
+    end
   end
 end
diff --git a/app/controllers/users/registrations_controller.rb b/app/controllers/users/registrations_controller.rb
index 44bcb2de..9332d422 100644
--- a/app/controllers/users/registrations_controller.rb
+++ b/app/controllers/users/registrations_controller.rb
@@ -1,37 +1,39 @@
 # frozen_string_literal: true
-class Users::RegistrationsController < Devise::RegistrationsController
-  before_action :configure_sign_up_params, only: [:create]
-  before_action :configure_account_update_params, only: [:update]
-  after_action :store_location, only: [:new]
+module Users
+  class RegistrationsController < Devise::RegistrationsController
+    before_action :configure_sign_up_params, only: [:create]
+    before_action :configure_account_update_params, only: [:update]
+    after_action :store_location, only: [:new]
 
-  protected
+    protected
 
-  def after_update_path_for(resource)
-    signed_in_root_path(resource)
-  end
+    def after_update_path_for(resource)
+      signed_in_root_path(resource)
+    end
 
-  def after_sign_in_path_for(resource)
-    stored = stored_location_for(User)
-    return stored if stored
+    def after_sign_in_path_for(resource)
+      stored = stored_location_for(User)
+      return stored if stored
 
-    if request.referer&.match(sign_in_url) || request.referer&.match(sign_up_url)
-      super
-    else
-      request.referer || root_path
+      if request.referer&.match(sign_in_url) || request.referer&.match(sign_up_url)
+        super
+      else
+        request.referer || root_path
+      end
+    end
+
+    private
+
+    def store_location
+      store_location_for(User, params[:redirect_to]) if params[:redirect_to]
+    end
+
+    def configure_sign_up_params
+      devise_parameter_sanitizer.permit(:sign_up, keys: [:name, :joinedwithcode])
+    end
+
+    def configure_account_update_params
+      devise_parameter_sanitizer.permit(:account_update, keys: [:image])
     end
   end
-
-  private
-
-  def store_location
-    store_location_for(User, params[:redirect_to]) if params[:redirect_to]
-  end
-
-  def configure_sign_up_params
-    devise_parameter_sanitizer.permit(:sign_up, keys: [:name, :joinedwithcode])
-  end
-
-  def configure_account_update_params
-    devise_parameter_sanitizer.permit(:account_update, keys: [:image])
-  end
 end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 96b5a2b2..e630e72d 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -2,12 +2,11 @@
 module ApplicationHelper
   def metacodeset
     metacodes = current_user.settings.metacodes
+
     return false unless metacodes[0].include?('metacodeset')
-    if metacodes[0].sub('metacodeset-', '') == 'Most'
-      return 'Most'
-    elsif metacodes[0].sub('metacodeset-', '') == 'Recent'
-      return 'Recent'
-    end
+    return 'Most' if metacodes[0].sub('metacodeset-', '') == 'Most'
+    return 'Recent' if metacodes[0].sub('metacodeset-', '') == 'Recent'
+
     MetacodeSet.find(metacodes[0].sub('metacodeset-', '').to_i)
   end
 
diff --git a/app/helpers/topics_helper.rb b/app/helpers/topics_helper.rb
index fa26095d..4fe9a597 100644
--- a/app/helpers/topics_helper.rb
+++ b/app/helpers/topics_helper.rb
@@ -4,7 +4,7 @@ module TopicsHelper
   def autocomplete_array_json(topics)
     topics.map do |t|
       is_map = t.is_a?(Map)
-      metamapMetacode = Metacode.find_by_name('Metamap')
+      metamap_metacode = Metacode.find_by(name: 'Metamap')
       {
         id: t.id,
         label: t.name,
@@ -17,8 +17,8 @@ module TopicsHelper
         rtype: is_map ? 'map' : 'topic',
         inmaps: is_map ? [] : t.inmaps(current_user),
         inmapsLinks: is_map ? [] : t.inmapsLinks(current_user),
-        type: is_map ? metamapMetacode.name : t.metacode.name,
-        typeImageURL: is_map ? metamapMetacode.icon : t.metacode.icon,
+        type: is_map ? metamap_metacode.name : t.metacode.name,
+        typeImageURL: is_map ? metamap_metacode.icon : t.metacode.icon,
         mapCount: is_map ? 0 : t.maps.count,
         synapseCount: is_map ? 0 : t.synapses.count
       }
diff --git a/app/models/access_request.rb b/app/models/access_request.rb
index fe68ce8f..2ca70954 100644
--- a/app/models/access_request.rb
+++ b/app/models/access_request.rb
@@ -12,7 +12,7 @@ class AccessRequest < ApplicationRecord
       Mailboxer::Receipt.where(notification: notification).update_all(is_read: true)
     end
 
-    user_map = UserMap.create(user: user, map: map)
+    UserMap.create(user: user, map: map)
     NotificationService.access_approved(self)
   end
 
diff --git a/app/models/event.rb b/app/models/event.rb
index cf974664..d764dbad 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 class Event < ApplicationRecord
-  KINDS = %w(user_present_on_map conversation_started_on_map 
-               topic_added_to_map topic_moved_on_map topic_removed_from_map
-               synapse_added_to_map synapse_removed_from_map
-               topic_updated synapse_updated).freeze
+  KINDS = %w(user_present_on_map conversation_started_on_map
+             topic_added_to_map topic_moved_on_map topic_removed_from_map
+             synapse_added_to_map synapse_removed_from_map
+             topic_updated synapse_updated).freeze
 
   belongs_to :eventable, polymorphic: true
   belongs_to :map
diff --git a/app/models/events/conversation_started_on_map.rb b/app/models/events/conversation_started_on_map.rb
index 20fb89c1..3d3df6ef 100644
--- a/app/models/events/conversation_started_on_map.rb
+++ b/app/models/events/conversation_started_on_map.rb
@@ -1,11 +1,13 @@
 # frozen_string_literal: true
-class Events::ConversationStartedOnMap < Event
-  # after_create :notify_users!
+module Events
+  class ConversationStartedOnMap < Event
+    # after_create :notify_users!
 
-  def self.publish!(map, user)
-    create!(kind: 'conversation_started_on_map',
-            eventable: map,
-            map: map,
-            user: user)
+    def self.publish!(map, user)
+      create!(kind: 'conversation_started_on_map',
+              eventable: map,
+              map: map,
+              user: user)
+    end
   end
 end
diff --git a/app/models/events/synapse_added_to_map.rb b/app/models/events/synapse_added_to_map.rb
index 5afa885d..cb6f83b0 100644
--- a/app/models/events/synapse_added_to_map.rb
+++ b/app/models/events/synapse_added_to_map.rb
@@ -1,12 +1,14 @@
 # frozen_string_literal: true
-class Events::SynapseAddedToMap < Event
-  # after_create :notify_users!
+module Events
+  class SynapseAddedToMap < Event
+    # after_create :notify_users!
 
-  def self.publish!(synapse, map, user, meta)
-    create!(kind: 'synapse_added_to_map',
-            eventable: synapse,
-            map: map,
-            user: user,
-            meta: meta)
+    def self.publish!(synapse, map, user, meta)
+      create!(kind: 'synapse_added_to_map',
+              eventable: synapse,
+              map: map,
+              user: user,
+              meta: meta)
+    end
   end
 end
diff --git a/app/models/events/synapse_removed_from_map.rb b/app/models/events/synapse_removed_from_map.rb
index b64035dd..9833e635 100644
--- a/app/models/events/synapse_removed_from_map.rb
+++ b/app/models/events/synapse_removed_from_map.rb
@@ -1,12 +1,14 @@
 # frozen_string_literal: true
-class Events::SynapseRemovedFromMap < Event
-  # after_create :notify_users!
+module Events
+  class SynapseRemovedFromMap < Event
+    # after_create :notify_users!
 
-  def self.publish!(synapse, map, user, meta)
-    create!(kind: 'synapse_removed_from_map',
-            eventable: synapse,
-            map: map,
-            user: user,
-            meta: meta)
+    def self.publish!(synapse, map, user, meta)
+      create!(kind: 'synapse_removed_from_map',
+              eventable: synapse,
+              map: map,
+              user: user,
+              meta: meta)
+    end
   end
 end
diff --git a/app/models/events/synapse_updated.rb b/app/models/events/synapse_updated.rb
index 0d85cbe8..a0d8992d 100644
--- a/app/models/events/synapse_updated.rb
+++ b/app/models/events/synapse_updated.rb
@@ -1,11 +1,13 @@
 # frozen_string_literal: true
-class Events::SynapseUpdated < Event
-  # after_create :notify_users!
+module Events
+  class SynapseUpdated < Event
+    # after_create :notify_users!
 
-  def self.publish!(synapse, user, meta)
-    create!(kind: 'synapse_updated',
-            eventable: synapse,
-            user: user,
-            meta: meta)
+    def self.publish!(synapse, user, meta)
+      create!(kind: 'synapse_updated',
+              eventable: synapse,
+              user: user,
+              meta: meta)
+    end
   end
 end
diff --git a/app/models/events/topic_added_to_map.rb b/app/models/events/topic_added_to_map.rb
index a3fa62cf..c485a5ce 100644
--- a/app/models/events/topic_added_to_map.rb
+++ b/app/models/events/topic_added_to_map.rb
@@ -1,12 +1,14 @@
 # frozen_string_literal: true
-class Events::TopicAddedToMap < Event
-  # after_create :notify_users!
+module Events
+  class TopicAddedToMap < Event
+    # after_create :notify_users!
 
-  def self.publish!(topic, map, user, meta)
-    create!(kind: 'topic_added_to_map',
-            eventable: topic,
-            map: map,
-            user: user,
-            meta: meta)
+    def self.publish!(topic, map, user, meta)
+      create!(kind: 'topic_added_to_map',
+              eventable: topic,
+              map: map,
+              user: user,
+              meta: meta)
+    end
   end
 end
diff --git a/app/models/events/topic_moved_on_map.rb b/app/models/events/topic_moved_on_map.rb
index 08d01277..5805a73f 100644
--- a/app/models/events/topic_moved_on_map.rb
+++ b/app/models/events/topic_moved_on_map.rb
@@ -1,12 +1,14 @@
 # frozen_string_literal: true
-class Events::TopicMovedOnMap < Event
-  # after_create :notify_users!
+module Events
+  class TopicMovedOnMap < Event
+    # after_create :notify_users!
 
-  def self.publish!(topic, map, user, meta)
-    create!(kind: 'topic_moved_on_map',
-            eventable: topic,
-            map: map,
-            user: user,
-            meta: meta)
+    def self.publish!(topic, map, user, meta)
+      create!(kind: 'topic_moved_on_map',
+              eventable: topic,
+              map: map,
+              user: user,
+              meta: meta)
+    end
   end
 end
diff --git a/app/models/events/topic_removed_from_map.rb b/app/models/events/topic_removed_from_map.rb
index 2f03ec26..f82e04d5 100644
--- a/app/models/events/topic_removed_from_map.rb
+++ b/app/models/events/topic_removed_from_map.rb
@@ -1,12 +1,14 @@
 # frozen_string_literal: true
-class Events::TopicRemovedFromMap < Event
-  # after_create :notify_users!
+module Events
+  class TopicRemovedFromMap < Event
+    # after_create :notify_users!
 
-  def self.publish!(topic, map, user, meta)
-    create!(kind: 'topic_removed_from_map',
-            eventable: topic,
-            map: map,
-            user: user,
-            meta: meta)
+    def self.publish!(topic, map, user, meta)
+      create!(kind: 'topic_removed_from_map',
+              eventable: topic,
+              map: map,
+              user: user,
+              meta: meta)
+    end
   end
 end
diff --git a/app/models/events/topic_updated.rb b/app/models/events/topic_updated.rb
index fd41a4d6..d52a4298 100644
--- a/app/models/events/topic_updated.rb
+++ b/app/models/events/topic_updated.rb
@@ -1,11 +1,13 @@
 # frozen_string_literal: true
-class Events::TopicUpdated < Event
-  # after_create :notify_users!
+module Events
+  class TopicUpdated < Event
+    # after_create :notify_users!
 
-  def self.publish!(topic, user, meta)
-    create!(kind: 'topic_updated',
-            eventable: topic,
-            user: user,
-            meta: meta)
+    def self.publish!(topic, user, meta)
+      create!(kind: 'topic_updated',
+              eventable: topic,
+              user: user,
+              meta: meta)
+    end
   end
 end
diff --git a/app/models/events/user_present_on_map.rb b/app/models/events/user_present_on_map.rb
index 38d524ef..34b7dae9 100644
--- a/app/models/events/user_present_on_map.rb
+++ b/app/models/events/user_present_on_map.rb
@@ -1,11 +1,13 @@
 # frozen_string_literal: true
-class Events::UserPresentOnMap < Event
-  # after_create :notify_users!
+module Events
+  class UserPresentOnMap < Event
+    # after_create :notify_users!
 
-  def self.publish!(map, user)
-    create!(kind: 'user_present_on_map',
-            eventable: map,
-            map: map,
-            user: user)
+    def self.publish!(map, user)
+      create!(kind: 'user_present_on_map',
+              eventable: map,
+              map: map,
+              user: user)
+    end
   end
 end
diff --git a/app/models/map.rb b/app/models/map.rb
index 4f86d6f8..e85cc09b 100644
--- a/app/models/map.rb
+++ b/app/models/map.rb
@@ -3,8 +3,10 @@ class Map < ApplicationRecord
   belongs_to :user
   belongs_to :source, class_name: :Map
 
-  has_many :topicmappings, -> { Mapping.topicmapping }, class_name: :Mapping, dependent: :destroy
-  has_many :synapsemappings, -> { Mapping.synapsemapping }, class_name: :Mapping, dependent: :destroy
+  has_many :topicmappings, -> { Mapping.topicmapping },
+           class_name: :Mapping, dependent: :destroy
+  has_many :synapsemappings, -> { Mapping.synapsemapping },
+           class_name: :Mapping, dependent: :destroy
   has_many :topics, through: :topicmappings, source: :mappable, source_type: 'Topic'
   has_many :synapses, through: :synapsemappings, source: :mappable, source_type: 'Synapse'
   has_many :messages, as: :resource, dependent: :destroy
@@ -21,7 +23,6 @@ class Map < ApplicationRecord
   has_attached_file :screenshot,
                     styles: {
                       thumb: ['220x220#', :png]
-                      #:full => ['940x630#', :png]
                     },
                     default_url: 'https://s3.amazonaws.com/metamaps-assets/site/missing-map-square.png'
 
@@ -31,7 +32,7 @@ class Map < ApplicationRecord
   validates :permission, inclusion: { in: Perm::ISSIONS.map(&:to_s) }
 
   # Validate the attached image is image/jpg, image/png, etc
-  validates_attachment_content_type :screenshot, content_type: /\Aimage\/.*\Z/
+  validates_attachment_content_type :screenshot, content_type: %r{\Aimage/.*\Z}
 
   after_update :after_updated
   after_save :update_deferring_topics_and_synapses, if: :permission_changed?
@@ -80,7 +81,12 @@ class Map < ApplicationRecord
   end
 
   def as_json(_options = {})
-    json = super(methods: [:user_name, :user_image, :star_count, :topic_count, :synapse_count, :contributor_count, :collaborator_ids, :screenshot_url], except: [:screenshot_content_type, :screenshot_file_size, :screenshot_file_name, :screenshot_updated_at])
+    json = super(
+      methods: [:user_name, :user_image, :star_count, :topic_count, :synapse_count,
+                :contributor_count, :collaborator_ids, :screenshot_url],
+      except: [:screenshot_content_type, :screenshot_file_size, :screenshot_file_name,
+               :screenshot_updated_at]
+    )
     json[:created_at_clean] = created_at_str
     json[:updated_at_clean] = updated_at_str
     json
@@ -120,17 +126,16 @@ class Map < ApplicationRecord
     end
     removed.compact
   end
-  
+
   def after_updated
-    attrs = ['name', 'desc', 'permission']
-    if attrs.any? {|k| changed_attributes.key?(k)}
-      ActionCable.server.broadcast 'map_' + id.to_s, type: 'mapUpdated'
-    end
+    attrs = %w(name desc permission)
+    return unless attrs.any? { |k| changed_attributes.key?(k) }
+    ActionCable.server.broadcast 'map_' + id.to_s, type: 'mapUpdated'
   end
 
   def update_deferring_topics_and_synapses
-    Topic.where(defer_to_map_id: id).update_all(permission: permission)
-    Synapse.where(defer_to_map_id: id).update_all(permission: permission)
+    Topic.where(defer_to_map_id: id).update(permission: permission)
+    Synapse.where(defer_to_map_id: id).update(permission: permission)
   end
 
   def invited_text
diff --git a/app/models/mapping.rb b/app/models/mapping.rb
index 7a82be76..348a5e92 100644
--- a/app/models/mapping.rb
+++ b/app/models/mapping.rb
@@ -31,7 +31,7 @@ class Mapping < ApplicationRecord
 
   def after_created
     if mappable_type == 'Topic'
-      meta = {'x': xloc, 'y': yloc, 'mapping_id': id}
+      meta = { 'x': xloc, 'y': yloc, 'mapping_id': id }
       Events::TopicAddedToMap.publish!(mappable, map, user, meta)
       ActionCable.server.broadcast 'map_' + map.id.to_s, type: 'topicAdded', topic: mappable.filtered, mapping_id: id
     elsif mappable_type == 'Synapse'
@@ -42,13 +42,14 @@ class Mapping < ApplicationRecord
         synapse: mappable.filtered,
         topic1: mappable.topic1.filtered,
         topic2: mappable.topic2.filtered,
-        mapping_id: id)
+        mapping_id: id
+      )
     end
   end
 
   def after_updated
-    if mappable_type == 'Topic' and (xloc_changed? or yloc_changed?)
-      meta = {'x': xloc, 'y': yloc, 'mapping_id': id}
+    if (mappable_type == 'Topic') && (xloc_changed? || yloc_changed?)
+      meta = { 'x': xloc, 'y': yloc, 'mapping_id': id }
       Events::TopicMovedOnMap.publish!(mappable, map, updated_by, meta)
       ActionCable.server.broadcast 'map_' + map.id.to_s, type: 'topicMoved', id: mappable.id, mapping_id: id, x: xloc, y: yloc
     end
@@ -61,7 +62,7 @@ class Mapping < ApplicationRecord
       mappable.save
     end
 
-    meta = {'mapping_id': id}
+    meta = { 'mapping_id': id }
     if mappable_type == 'Topic'
       Events::TopicRemovedFromMap.publish!(mappable, map, updated_by, meta)
       ActionCable.server.broadcast 'map_' + map.id.to_s, type: 'topicRemoved', id: mappable.id, mapping_id: id
diff --git a/app/models/message.rb b/app/models/message.rb
index de7fd5d1..d26ce9d6 100644
--- a/app/models/message.rb
+++ b/app/models/message.rb
@@ -4,7 +4,7 @@ class Message < ApplicationRecord
   belongs_to :resource, polymorphic: true
 
   delegate :name, to: :user, prefix: true
-  
+
   after_create :after_created
 
   def user_image
@@ -15,8 +15,8 @@ class Message < ApplicationRecord
     json = super(methods: [:user_name, :user_image])
     json
   end
-  
+
   def after_created
-    ActionCable.server.broadcast 'map_' + resource.id.to_s, type: 'messageCreated', message: self.as_json
+    ActionCable.server.broadcast 'map_' + resource.id.to_s, type: 'messageCreated', message: as_json
   end
 end
diff --git a/app/models/synapse.rb b/app/models/synapse.rb
index d6d08bbe..8106dfd8 100644
--- a/app/models/synapse.rb
+++ b/app/models/synapse.rb
@@ -64,16 +64,16 @@ class Synapse < ApplicationRecord
   end
 
   def after_updated
-    attrs = ['desc', 'category', 'permission', 'defer_to_map_id']
-    if attrs.any? {|k| changed_attributes.key?(k)}
-      new = self.attributes.select {|k| attrs.include?(k) }
-      old = changed_attributes.select {|k| attrs.include?(k) }
-      meta = new.merge(old) # we are prioritizing the old values, keeping them 
-      meta['changed'] = changed_attributes.keys.select {|k| attrs.include?(k) }
+    attrs = %w(desc category permission defer_to_map_id)
+    if attrs.any? { |k| changed_attributes.key?(k) }
+      new = attributes.select { |k| attrs.include?(k) }
+      old = changed_attributes.select { |k| attrs.include?(k) }
+      meta = new.merge(old) # we are prioritizing the old values, keeping them
+      meta['changed'] = changed_attributes.keys.select { |k| attrs.include?(k) }
       Events::SynapseUpdated.publish!(self, user, meta)
-      maps.each {|map|
+      maps.each do |map|
         ActionCable.server.broadcast 'map_' + map.id.to_s, type: 'synapseUpdated', id: id
-      }
+      end
     end
   end
 end
diff --git a/app/models/topic.rb b/app/models/topic.rb
index 2273fd7e..69587135 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -160,16 +160,16 @@ class Topic < ApplicationRecord
   end
 
   def after_updated
-    attrs = ['name', 'desc', 'link', 'metacode_id', 'permission', 'defer_to_map_id']
-    if attrs.any? {|k| changed_attributes.key?(k)}
-      new = self.attributes.select {|k| attrs.include?(k) }
-      old = changed_attributes.select {|k| attrs.include?(k) }
-      meta = new.merge(old) # we are prioritizing the old values, keeping them 
-      meta['changed'] = changed_attributes.keys.select {|k| attrs.include?(k) }
+    attrs = %w(name desc link metacode_id permission defer_to_map_id)
+    if attrs.any? { |k| changed_attributes.key?(k) }
+      new = attributes.select { |k| attrs.include?(k) }
+      old = changed_attributes.select { |k| attrs.include?(k) }
+      meta = new.merge(old) # we are prioritizing the old values, keeping them
+      meta['changed'] = changed_attributes.keys.select { |k| attrs.include?(k) }
       Events::TopicUpdated.publish!(self, user, meta)
-      maps.each {|map|
+      maps.each do |map|
         ActionCable.server.broadcast 'map_' + map.id.to_s, type: 'topicUpdated', id: id
-      }
+      end
     end
   end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 17d9c8d4..915d06db 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -104,7 +104,7 @@ class User < ApplicationRecord
     if code == joinedwithcode
       update(generation: 0)
     else
-      update(generation: User.find_by_code(joinedwithcode).generation + 1)
+      update(generation: User.find_by(code: joinedwithcode).generation + 1)
     end
   end
 
diff --git a/app/models/user_preference.rb b/app/models/user_preference.rb
index 29ca3948..cb200d3c 100644
--- a/app/models/user_preference.rb
+++ b/app/models/user_preference.rb
@@ -6,7 +6,7 @@ class UserPreference
     array = []
     %w(Action Aim Idea Question Note Wildcard Subject).each do |m|
       begin
-        metacode = Metacode.find_by_name(m)
+        metacode = Metacode.find_by(name: m)
         array.push(metacode.id.to_s) if metacode
       rescue ActiveRecord::StatementInvalid
         if m == 'Action'
diff --git a/app/models/webhooks/slack/synapse_removed_from_map.rb b/app/models/webhooks/slack/synapse_removed_from_map.rb
index 06d31206..532488e8 100644
--- a/app/models/webhooks/slack/synapse_removed_from_map.rb
+++ b/app/models/webhooks/slack/synapse_removed_from_map.rb
@@ -2,7 +2,7 @@
 class Webhooks::Slack::SynapseRemovedFromMap < Webhooks::Slack::Base
   def text
     connector = eventable.desc.empty? ? '->' : eventable.desc
-    # todo express correct directionality of arrows when desc is empty
+    # TODO: express correct directionality of arrows when desc is empty
     "\"*#{eventable.topic1.name}* #{connector} *#{eventable.topic2.name}*\" was removed by *#{event.user.name}* as a connection from the map *#{view_map_on_metamaps}*"
   end
 end
diff --git a/realtime/map.js b/realtime/map.js
index cbebce82..9d8a1582 100644
--- a/realtime/map.js
+++ b/realtime/map.js
@@ -9,7 +9,7 @@ const {
   LEAVE_MAP,
   SEND_COORDS,
   SEND_MAPPER_INFO,
-  DRAG_TOPIC,
+  DRAG_TOPIC
 } = require('../frontend/src/Metamaps/Realtime/events')
 
 const { mapRoom, userMapRoom } = require('./rooms')
diff --git a/webpack.config.js b/webpack.config.js
index 423616f9..13cf6a65 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -23,7 +23,7 @@ if (NODE_ENV === 'production') {
 
 const devtool = NODE_ENV === 'production' ? undefined : 'cheap-module-eval-source-map'
 
-const config = module.exports = {
+module.exports = {
   context: __dirname,
   plugins,
   devtool,