diff --git a/app/controllers/registrations_controller.rb b/app/controllers/registrations_controller.rb
index 52db44bf82..97aa2d9bdb 100644
--- a/app/controllers/registrations_controller.rb
+++ b/app/controllers/registrations_controller.rb
@@ -15,11 +15,11 @@ class RegistrationsController < Devise::RegistrationsController
     super
   end
 
-  def after_sign_up_path_for(resource)
+  def after_sign_up_path_for(_resource)
     new_user_session_path
   end
 
-  def after_inactive_sign_up_path_for(resource)
+  def after_inactive_sign_up_path_for(_resource)
     new_user_session_path
   end
 
diff --git a/app/helpers/tree_helper.rb b/app/helpers/tree_helper.rb
index 5a96a208e9..d316213b1f 100644
--- a/app/helpers/tree_helper.rb
+++ b/app/helpers/tree_helper.rb
@@ -108,7 +108,7 @@ module TreeHelper
     end
   end
 
-  def up_dir_path(tree)
+  def up_dir_path
     file = File.join(@path, "..")
     tree_join(@ref, file)
   end
diff --git a/app/models/commit.rb b/app/models/commit.rb
index 37dd371ec0..baccf28674 100644
--- a/app/models/commit.rb
+++ b/app/models/commit.rb
@@ -75,11 +75,11 @@ class Commit
 
     return no_commit_message if title.blank?
 
-    title_end = title.index(/\n/)
+    title_end = title.index("\n")
     if (!title_end && title.length > 100) || (title_end && title_end > 100)
       title[0..79] << "&hellip;".html_safe
     else
-      title.split(/\n/, 2).first
+      title.split("\n", 2).first
     end
   end
 
@@ -87,11 +87,11 @@ class Commit
   #
   # cut off, ellipses (`&hellp;`) are prepended to the commit message.
   def description
-    title_end = safe_message.index(/\n/)
+    title_end = safe_message.index("\n")
     @description ||= if (!title_end && safe_message.length > 100) || (title_end && title_end > 100)
                     "&hellip;".html_safe << safe_message[80..-1]
                   else
-                    safe_message.split(/\n/, 2)[1].try(:chomp)
+                    safe_message.split("\n", 2)[1].try(:chomp)
                   end
   end
 
diff --git a/app/models/key.rb b/app/models/key.rb
index 095c73d8ba..65a426d1f8 100644
--- a/app/models/key.rb
+++ b/app/models/key.rb
@@ -89,7 +89,7 @@ class Key < ActiveRecord::Base
     end
 
     if cmd_status.zero?
-      cmd_output.gsub /([\d\h]{2}:)+[\d\h]{2}/ do |match|
+      cmd_output.gsub /(\h{2}:)+\h{2}/ do |match|
         self.fingerprint = match
       end
     end
diff --git a/app/models/project_services/campfire_service.rb b/app/models/project_services/campfire_service.rb
index 0736ddab99..3116c31105 100644
--- a/app/models/project_services/campfire_service.rb
+++ b/app/models/project_services/campfire_service.rb
@@ -60,9 +60,9 @@ class CampfireService < Service
     message << "[#{project.name_with_namespace}] "
     message << "#{push[:user_name]} "
 
-    if before =~ /000000/
+    if before.include?('000000')
       message << "pushed new branch #{ref} \n"
-    elsif after =~ /000000/
+    elsif after.include?('000000')
       message << "removed branch #{ref} \n"
     else
       message << "pushed #{push[:total_commits_count]} commits to #{ref}. "
diff --git a/app/models/project_services/hipchat_service.rb b/app/models/project_services/hipchat_service.rb
index 6ef4b210c5..aafc3efa97 100644
--- a/app/models/project_services/hipchat_service.rb
+++ b/app/models/project_services/hipchat_service.rb
@@ -58,12 +58,12 @@ class HipchatService < Service
 
     message = ""
     message << "#{push[:user_name]} "
-    if before =~ /000000/
+    if before.include?('000000')
       message << "pushed new branch <a href=\""\
                  "#{project.web_url}/commits/#{URI.escape(ref)}\">#{ref}</a>"\
                  " to <a href=\"#{project.web_url}\">"\
                  "#{project.name_with_namespace.gsub!(/\s/, "")}</a>\n"
-    elsif after =~ /000000/
+    elsif after.include?('000000')
       message << "removed branch #{ref} from <a href=\"#{project.web_url}\">#{project.name_with_namespace.gsub!(/\s/,'')}</a> \n"
     else
       message << "pushed to branch <a href=\""\
diff --git a/app/models/project_services/pushover_service.rb b/app/models/project_services/pushover_service.rb
index f247fde776..a9b23f97ba 100644
--- a/app/models/project_services/pushover_service.rb
+++ b/app/models/project_services/pushover_service.rb
@@ -80,9 +80,9 @@ class PushoverService < Service
     before = push_data[:before]
     after = push_data[:after]
 
-    if before =~ /000000/
+    if before.include?('000000')
       message = "#{push_data[:user_name]} pushed new branch \"#{ref}\"."
-    elsif after =~ /000000/
+    elsif after.include?('000000')
       message = "#{push_data[:user_name]} deleted branch \"#{ref}\"."
     else
       message = "#{push_data[:user_name]} push to branch \"#{ref}\"."
diff --git a/app/models/project_services/slack_message.rb b/app/models/project_services/slack_message.rb
index d0ddb1f162..6c6446db45 100644
--- a/app/models/project_services/slack_message.rb
+++ b/app/models/project_services/slack_message.rb
@@ -77,11 +77,11 @@ class SlackMessage
   end
 
   def new_branch?
-    before =~ /000000/
+    before.include?('000000')
   end
 
   def removed_branch?
-    after =~ /000000/
+    after.include?('000000')
   end
 
   def branch_url
diff --git a/app/models/user.rb b/app/models/user.rb
index 6e5ac9b39c..743410c22e 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -488,7 +488,7 @@ class User < ActiveRecord::Base
   end
 
   def temp_oauth_email?
-    email =~ /\Atemp-email-for-oauth/
+    email.start_with?('temp-email-for-oauth')
   end
 
   def public_profile?
diff --git a/app/services/git_push_service.rb b/app/services/git_push_service.rb
index a9ea7daabc..872b886c57 100644
--- a/app/services/git_push_service.rb
+++ b/app/services/git_push_service.rb
@@ -111,23 +111,23 @@ class GitPushService
     ref_parts = ref.split('/')
 
     # Return if this is not a push to a branch (e.g. new commits)
-    ref_parts[1] =~ /heads/ && oldrev != Gitlab::Git::BLANK_SHA
+    ref_parts[1].include?('heads') && oldrev != Gitlab::Git::BLANK_SHA
   end
 
   def push_to_new_branch?(ref, oldrev)
     ref_parts = ref.split('/')
 
-    ref_parts[1] =~ /heads/ && oldrev == Gitlab::Git::BLANK_SHA
+    ref_parts[1].include?('heads') && oldrev == Gitlab::Git::BLANK_SHA
   end
 
   def push_remove_branch?(ref, newrev)
     ref_parts = ref.split('/')
 
-    ref_parts[1] =~ /heads/ && newrev == Gitlab::Git::BLANK_SHA
+    ref_parts[1].include?('heads') && newrev == Gitlab::Git::BLANK_SHA
   end
 
   def push_to_branch?(ref)
-    ref =~ /refs\/heads/
+    ref.include?('refs/heads')
   end
 
   def is_default_branch?(ref)
diff --git a/app/services/notification_service.rb b/app/services/notification_service.rb
index fb8f812dad..5a89c5d293 100644
--- a/app/services/notification_service.rb
+++ b/app/services/notification_service.rb
@@ -118,7 +118,7 @@ class NotificationService
     return true unless note.noteable_type.present?
 
     # ignore gitlab service messages
-    return true if note.note =~ /\A_Status changed to closed_/
+    return true if note.note.start_with?('_Status changed to closed_')
     return true if note.cross_reference? && note.system == true
 
     opts = { noteable_type: note.noteable_type, project_id: note.project_id }
diff --git a/app/views/layouts/_head.html.haml b/app/views/layouts/_head.html.haml
index fa6aecb666..17bcf8d363 100644
--- a/app/views/layouts/_head.html.haml
+++ b/app/views/layouts/_head.html.haml
@@ -19,6 +19,7 @@
   = csrf_meta_tags
   = include_gon
   %meta{name: 'viewport', content: 'width=device-width, initial-scale=1.0'}
+  %meta{name: 'theme-color', content: '#474D57'}
 
   = render 'layouts/google_analytics' if extra_config.has_key?('google_analytics_id')
   = render 'layouts/piwik' if extra_config.has_key?('piwik_url') && extra_config.has_key?('piwik_site_id')
diff --git a/app/views/projects/_blob_editor.html.haml b/app/views/projects/_blob_editor.html.haml
new file mode 100644
index 0000000000..1fb74b55c4
--- /dev/null
+++ b/app/views/projects/_blob_editor.html.haml
@@ -0,0 +1,15 @@
+.file-holder.file
+  .file-title
+    %i.icon-file
+    %span.file_name
+      %span.monospace.light #{ref}
+      - if local_assigns[:path]
+        = ': ' + local_assigns[:path]
+  .file-content.code
+    %pre.js-edit-mode-pane#editor
+      = params[:content] || local_assigns[:blob_data]
+    - if local_assigns[:path]
+      .js-edit-mode-pane#preview.hide
+        .center
+          %h2
+            %i.icon-spinner.icon-spin
diff --git a/app/views/projects/edit_tree/show.html.haml b/app/views/projects/edit_tree/show.html.haml
index 5ccde05063..7e0789853a 100644
--- a/app/views/projects/edit_tree/show.html.haml
+++ b/app/views/projects/edit_tree/show.html.haml
@@ -6,21 +6,7 @@
       = link_to editing_preview_title(@blob.name), '#preview', 'data-preview-url' => preview_project_edit_tree_path(@project, @id)
 
   = form_tag(project_edit_tree_path(@project, @id), method: :put, class: "form-horizontal") do
-    .file-holder.file
-      .file-title
-        %i.fa.fa-file
-        %span.file_name
-          %span.monospace.light #{@ref}:
-          = @path
-        %span.options
-          .btn-group.tree-btn-group
-            = link_to "Cancel", @after_edit_path, class: "btn btn-tiny btn-cancel", data: { confirm: leave_edit_message }
-      .file-content.code
-        %pre.js-edit-mode-pane#editor
-        .js-edit-mode-pane#preview.hide
-          .center
-            %h2
-              %i.fa.fa-spinner.fa-spin
+    = render 'projects/blob_editor', ref: @ref, path: @path, blob_data: @blob.data
     = render 'shared/commit_message_container', params: params,
              placeholder: "Update #{@blob.name}"
     = hidden_field_tag 'last_commit', @last_commit
@@ -34,7 +20,6 @@
   ace.config.loadModule("ace/ext/searchbox");
   var ace_mode = "#{@blob.language.try(:ace_mode)}";
   var editor = ace.edit("editor");
-  editor.setValue("#{escape_javascript(@blob.data)}");
   if (ace_mode) {
     editor.getSession().setMode('ace/mode/' + ace_mode);
   }
diff --git a/app/views/projects/new_tree/show.html.haml b/app/views/projects/new_tree/show.html.haml
index f09d365977..cf7b768694 100644
--- a/app/views/projects/new_tree/show.html.haml
+++ b/app/views/projects/new_tree/show.html.haml
@@ -19,12 +19,7 @@
         Encoding
       .col-sm-10
         = select_tag :encoding, options_for_select([ "base64", "text" ], "text"), class: 'form-control'
-    .file-holder
-      .file-title
-        %i.fa.fa-file
-      .file-content.code
-        %pre#editor= params[:content]
-
+    = render 'projects/blob_editor', ref: @ref
     = render 'shared/commit_message_container', params: params,
              placeholder: 'Add new file'
     = hidden_field_tag 'content', '', id: 'file-content'
diff --git a/app/views/projects/tree/_tree.html.haml b/app/views/projects/tree/_tree.html.haml
index 1159fcadff..68ccd4d61b 100644
--- a/app/views/projects/tree/_tree.html.haml
+++ b/app/views/projects/tree/_tree.html.haml
@@ -35,7 +35,7 @@
     - if @path.present?
       %tr.tree-item
         %td.tree-item-file-name
-          = link_to "..", project_tree_path(@project, up_dir_path(tree)), class: 'prepend-left-10'
+          = link_to "..", project_tree_path(@project, up_dir_path), class: 'prepend-left-10'
         %td
         %td.hidden-xs
 
diff --git a/config/routes.rb b/config/routes.rb
index 245d618563..9deddf3ead 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -154,8 +154,8 @@ Gitlab::Application.routes.draw do
     end
   end
 
-  match "/u/:username" => "users#show", as: :user,
-    constraints: {username: /(?:[^.]|\.(?!atom$))+/, format: /atom/}, via: :get
+  get '/u/:username' => 'users#show', as: :user,
+      constraints: { username: /(?:[^.]|\.(?!atom$))+/, format: /atom/ }
 
   #
   # Dashboard Area
diff --git a/features/project/commits/comments.feature b/features/project/commits/comments.feature
index a45245917e..afcf0fdbb0 100644
--- a/features/project/commits/comments.feature
+++ b/features/project/commits/comments.feature
@@ -13,11 +13,6 @@ Feature: Project Commits Comments
   Scenario: I can't cancel the main form
     Then I should not see the cancel comment button
 
-  @javascript
-  Scenario: I can't preview without text
-    Given I haven't written any comment text
-    Then The comment preview tab should say there is nothing to do
-
   @javascript
   Scenario: I can preview with text
     Given I write a comment like ":+1: Nice"
diff --git a/features/project/commits/diff_comments.feature b/features/project/commits/diff_comments.feature
index 9c4cc723d1..56b9a13678 100644
--- a/features/project/commits/diff_comments.feature
+++ b/features/project/commits/diff_comments.feature
@@ -54,12 +54,6 @@ Feature: Project Commits Diff Comments
     Given I leave a diff comment like "Typo, please fix"
     Then I should see a discussion reply button
 
-  @javascript
-  Scenario: I can't preview without text
-    Given I open a diff comment form
-    And I haven't written any diff comment text
-    Then The diff comment preview tab should say there is nothing to do
-
   @javascript
   Scenario: I can preview with text
     Given I open a diff comment form
diff --git a/features/steps/shared/diff_note.rb b/features/steps/shared/diff_note.rb
index 28964d54a8..510e0f0f93 100644
--- a/features/steps/shared/diff_note.rb
+++ b/features/steps/shared/diff_note.rb
@@ -80,7 +80,7 @@ module SharedDiffNote
 
   step 'I should not see the diff comment text field' do
     within(diff_file_selector) do
-      page.should have_css(".js-note-text", visible: false)
+      expect(find('.js-note-text')).not_to be_visible
     end
   end
 
@@ -115,7 +115,7 @@ module SharedDiffNote
   end
 
   step 'I should see add a diff comment button' do
-    page.should have_css(".js-add-diff-note-button", visible: false)
+    page.should have_css('.js-add-diff-note-button', visible: true)
   end
 
   step 'I should see an empty diff comment form' do
diff --git a/features/steps/shared/note.rb b/features/steps/shared/note.rb
index 17adec3eda..625bcc0b26 100644
--- a/features/steps/shared/note.rb
+++ b/features/steps/shared/note.rb
@@ -64,7 +64,7 @@ module SharedNote
 
   step 'I should not see the comment text field' do
     within(".js-main-target-form") do
-      page.should have_css(".js-note-text", visible: false)
+      expect(find('.js-note-text')).not_to be_visible
     end
   end
 
diff --git a/lib/api/internal.rb b/lib/api/internal.rb
index 180e50611c..a999cff09c 100644
--- a/lib/api/internal.rb
+++ b/lib/api/internal.rb
@@ -25,8 +25,8 @@ module API
         # project. This applies the correct project permissions to
         # the wiki repository as well.
         access =
-          if project_path =~ /\.wiki\Z/
-            project_path.sub!(/\.wiki\Z/, '')
+          if project_path.end_with?('.wiki')
+            project_path.chomp!('.wiki')
             Gitlab::GitAccessWiki.new
           else
             Gitlab::GitAccess.new
diff --git a/lib/tasks/gitlab/import.rake b/lib/tasks/gitlab/import.rake
index 3c693546c0..fef2afd733 100644
--- a/lib/tasks/gitlab/import.rake
+++ b/lib/tasks/gitlab/import.rake
@@ -25,7 +25,7 @@ namespace :gitlab do
 
         puts "Processing #{repo_path}".yellow
 
-        if path =~ /\.wiki\Z/
+        if path.end_with?('.wiki')
           puts " * Skipping wiki repo"
           next
         end