Use Redcarpet for plain text rendering

config/initializers/markdown.rb

@@ -1,4 +1,7 @@
 ActiveSupport.on_load :action_text_markdown do
   require "markdown_renderer"
+  require "redcarpet/render_strip"
+
   ActionText::Markdown.html_renderer = ->(content) { MarkdownRenderer.build.render(content) }
+  ActionText::Markdown.plain_text_renderer = Redcarpet::Markdown.new(Redcarpet::Render::StripDown)
 end

lib/rails_ext/action_text_markdown.rb

@@ -1,7 +1,7 @@
 module ActionText
   class Markdown < Record
     mattr_accessor :html_renderer
-    mattr_accessor :plain_renderer
+    mattr_accessor :plain_text_renderer
 
     belongs_to :record, polymorphic: true, touch: true
 
@@ -18,10 +18,10 @@ module ActionText
     end
 
     def to_plain_text
-      if plain_renderer.respond_to? :call
-        plain_renderer.call content
+      if plain_text_renderer.respond_to? :call
+        plain_text_renderer.call content
       else
-        plain_renderer.render content
+        plain_text_renderer.render content
       end
     end
   end

test/models/bubble_test.rb

@@ -10,7 +10,7 @@ class BubbleTest < ActiveSupport::TestCase
       bubbles(:logo).capture Comment.new(body: "Agreed.")
     end
 
-    assert_equal "Agreed.", bubbles(:logo).messages.last.messageable.body.to_plain_text
+    assert_equal "Agreed.", bubbles(:logo).messages.last.messageable.body.to_plain_text.chomp
   end
 
   test "boosting" do