Enable Layout/TrailingWhitespace cop to prevent extra trailing spac…

…e in future

.rubocop.yml

@@ -46,3 +46,6 @@ Layout/SpaceBeforeFirstArg:
 # Use `{ a: 1 }` not `{a:1}`.
 Layout/SpaceInsideHashLiteralBraces:
   Enabled: true
+
+Layout/TrailingWhitespace:
+  Enabled: true

Gemfile

@@ -12,7 +12,7 @@ c_platforms = Bundler::Dsl::VALID_PLATFORMS.dup.delete_if do |platform|
   platform =~ /jruby/
 end
 
-gem "rubocop", "0.68.1", require: false
+gem "rubocop", require: false
 
 # Alternative solution that might work, but it has bad interactions with
 # Gemfile.lock if that gets committed/reused:

lib/rack/mock.rb

@@ -177,7 +177,7 @@ class MockResponse < Rack::Response
     class << self
       alias [] new
     end
-    
+
     # Headers
     attr_reader :original_headers, :cookies
 

lib/rack/multipart/parser.rb

@@ -347,7 +347,7 @@ def tag_multipart_encoding(filename, content_type, name, body)
           type_subtype = list.first
           type_subtype.strip!
           if TEXT_PLAIN == type_subtype
-            rest         = list.drop 1
+            rest = list.drop 1
             rest.each do |param|
               k, v = param.split('=', 2)
               k.strip!

lib/rack/response.rb

@@ -24,7 +24,7 @@ class Response
     def self.[](status, headers, body)
       self.new(body, status, headers)
     end
-    
+
     attr_accessor :length, :status, :body
     attr_reader :header
     alias headers header

test/spec_files.rb

@@ -20,7 +20,7 @@ def files(*args)
     request = Rack::Request.new(
       Rack::MockRequest.env_for("/cgi/test")
     )
-    
+
     file_path = File.expand_path("cgi/test", __dir__)
     status, headers, body = app.serving(request, file_path)
     assert_equal 200, status

test/spec_response.rb

@@ -16,7 +16,7 @@
     response.headers.must_equal headers
     response.body.must_equal body
   end
-  
+
   it 'has cache-control methods' do
     response = Rack::Response.new
     cc = 'foo'