Add option to strip trailing newlines from ERB templates

Add failing test for views with trailing newlines

Add and test config option

Move config option to config/application.rb

Move implementation to ERB template handler

Move config option to ActionView::Template::Handlers::ERB

actionview/lib/action_view/template/handlers/erb.rb

@@ -16,6 +16,9 @@ class ERB
  # Do not escape templates of these mime types.
  class_attribute :escape_ignore_list, default: ["text/plain"]
 
+ # Strip trailing newlines from rendered output
+ class_attribute :strip_trailing_newlines, default: false
+
  ENCODING_TAG = Regexp.new("\\A(<%#{ENCODING_FLAG}-?%>)[ \\t]*")
 
  def self.call(template, source)
@@ -45,6 +48,9 @@ def call(template, source)
  # Always make sure we return a String in the default_internal
  erb.encode!
 
+ # Strip trailing newlines from the template if enabled
+ erb.chomp! if strip_trailing_newlines
+
  options = {
  escape: (self.class.escape_ignore_list.include? template.type),
  trim: (self.class.erb_trim_mode == "-")

actionview/test/actionpack/abstract/abstract_controller_test.rb

@@ -52,6 +52,10 @@ def index
  render "index.erb"
  end
 
+ def with_final_newline
+ render "with_final_newline.erb"
+ end
+
  def index_to_string
  self.response_body = render_to_string "index"
  end
@@ -84,6 +88,14 @@ def setup
  assert_equal "Hello from index.erb", @controller.response_body
  end
 
+ test "stripping final newline works" do
+ ActionView::Template::Handlers::ERB.strip_trailing_newlines = true
+ @controller.process(:with_final_newline)
+ assert_equal "Hello from with_final_newline.erb", @controller.response_body
+ ensure
+ ActionView::Template::Handlers::ERB.strip_trailing_newlines = false
+ end
+
  test "render_to_string works with a String as an argument" do
  @controller.process(:index_to_string)
  assert_equal "Hello from index.erb", @controller.response_body

actionview/test/actionpack/abstract/views/with_final_newline.erb

@@ -0,0 +1 @@
+Hello from with_final_newline.erb