[refs #579] small refactoring

app/helpers/comments_helper.rb

@@ -17,9 +17,9 @@ module CommentsHelper
   end
 
   def project_commentable_comments_path(project, commentable)
-    if commentable.class == Issue
+    if commentable.is_a? Issue
       project_issue_comments_path(@project, @commentable)
-    elsif commentable.class == Grit::Commit
+    elsif commentable.is_a? Grit::Commit
       project_commit_comments_path(@project, @commentable)
     end
   end

app/helpers/diff_helper.rb

@@ -258,9 +258,9 @@ module DiffHelper
 
   def new_comment_path
     hash = {:path => @filepath, :line => @num_line}
-    if @commentable.class == Issue
+    if @commentable.is_a? Issue
       project_new_line_pull_comment_path(@project, @commentable, hash.merge({:in_reply => @add_reply_id}))
-    elsif @commentable.class == Grit::Commit
+    elsif @commentable.is_a? Grit::Commit
       new_line_commit_comment_path(@project, @commentable, hash)
     end
   end

app/models/comment.rb

@@ -84,7 +84,7 @@ class Comment < ActiveRecord::Base
   end
 
   def pull_comment?
-    return true if commentable.class == Issue && commentable.pull_request.present?
+    return true if commentable.is_a?(Issue) && commentable.pull_request.present?
   end
 
   def set_additional_data params
@@ -94,7 +94,7 @@ class Comment < ActiveRecord::Base
       return true
     end
     self.data = {:path => params[:path], :line => params[:line]}
-    if commentable.class == Issue && pull = commentable.pull_request
+    if commentable.is_a?(Issue) && pull = commentable.pull_request
       diff_path = pull.diff.select {|d| d.a_path == params[:path]}
       return false unless actual_inline_comment?(pull.diff, true)