Corrected with rubocop cop 'Lint/DeprecatedClassMethods'.

app/models/package.rb

@@ -71,7 +71,7 @@ class Package < ApplicationModel
         File.delete( entry )
       end
       backup_file = entry + '.link_backup'
-      if File.exists?( backup_file )
+      if File.exist?( backup_file )
         logger.info "Restore backup file of #{backup_file} -> #{entry}."
         File.rename( backup_file, entry )
       end
@@ -114,7 +114,7 @@ class Package < ApplicationModel
       end
 
       backup_file = dest.to_s + '.link_backup'
-      if File.exists?( backup_file )
+      if File.exist?( backup_file )
         logger.info "Restore backup file of #{backup_file} -> #{dest.to_s}."
         File.rename( backup_file, dest.to_s )
       end
@@ -145,7 +145,7 @@ class Package < ApplicationModel
       dest = @@root + '/' + file
 
       if File.directory?( entry.to_s )
-        if !File.exists?( dest.to_s )
+        if !File.exist?( dest.to_s )
           logger.info "Create dir: #{dest.to_s}"
           FileUtils.mkdir_p( dest.to_s )
         end
@@ -153,7 +153,7 @@ class Package < ApplicationModel
 
       if File.file?( entry.to_s ) && ( File.file?( dest.to_s ) && !File.symlink?( dest.to_s ) )
         backup_file = dest.to_s + '.link_backup'
-        if File.exists?( backup_file )
+        if File.exist?( backup_file )
           raise "Can't link #{entry.to_s} -> #{dest.to_s}, destination and .link_backup already exists!"
         else
           logger.info "Create backup file of #{dest.to_s} -> #{backup_file}."
@@ -441,7 +441,7 @@ class Package < ApplicationModel
     def self.migrate( package, direction = 'normal' )
       location = @@root + '/db/addon/' + package.underscore
 
-      return true if !File.exists?( location )
+      return true if !File.exist?( location )
       migrations_done = Package::Migration.where( name: package.underscore )
 
       # get existing migrations

config/boot.rb

@@ -3,4 +3,4 @@ require 'rubygems'
 # Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
 
-require 'bundler/setup' if File.exists?(ENV['BUNDLE_GEMFILE'])
+require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])

lib/sessions.rb

@@ -68,7 +68,7 @@ returns
     path = @path + '/'
 
     # just make sure that spool path exists
-    if !File::exists?( path )
+    if !File::exist?( path )
       FileUtils.mkpath path
     end
 
@@ -270,7 +270,7 @@ returns
     check = true
     count = 0
     while check
-      if File::exists?( path + filename )
+      if File::exist?( path + filename )
         count += 1
         filename = filename + '-' + count
       else
@@ -284,7 +284,7 @@ returns
       file.flock( File::LOCK_UN )
       file.close
     }
-    return false if !File.exists?( path + 'a-' + filename )
+    return false if !File.exist?( path + 'a-' + filename )
     FileUtils.mv( path + 'a-' + filename, path + filename )
     true
   end
@@ -419,7 +419,7 @@ returns
     }
     files.sort.each {|entry|
       filename = path + '/' + entry
-      next if !File::exists?( filename )
+      next if !File::exist?( filename )
       File.open( filename, 'rb' ) { |file|
         all = file.read
         spool = JSON.parse( all )
@@ -474,7 +474,7 @@ returns
   def self.jobs
 
     # just make sure that spool path exists
-    if !File::exists?( @path )
+    if !File::exist?( @path )
       FileUtils.mkpath @path
     end