Performance improvement - cache comments retrieved from GitHub

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 ## 0.3.0
 
+### New features
+
 ### Changes
 
 * [#29](https://github.com/mmozuras/pronto/issues/29): Be compatible and depend on rugged '0.21.0'.
+* Performance improvement - use Rugged::Blame instead of one provided by Grit.
+* Performance improvement - cache comments retrieved from GitHub.
+
+### Bugs fixed

lib/pronto/github.rb

@@ -1,8 +1,14 @@
 module Pronto
   class Github
+    def initialize
+      @comment_cache = {}
+    end
+
     def commit_comments(repo, sha)
-      client.commit_comments(repo, sha).map do |comment|
-        Comment.new(repo, sha, comment.body, comment.path, comment.body)
+      @comment_cache["#{repo}/#{sha}"] ||= begin
+        client.commit_comments(repo, sha).map do |comment|
+          Comment.new(repo, sha, comment.body, comment.path, comment.body)
+        end
       end
     end
 

spec/pronto/formatter/github_formattter_spec.rb

@@ -16,7 +16,7 @@ module Formatter
         specify do
           Octokit::Client.any_instance
                          .should_receive(:commit_comments)
-                         .twice
+                         .once
                          .and_return([])
 
           Octokit::Client.any_instance

spec/pronto/github_spec.rb

@@ -0,0 +1,27 @@
+require 'spec_helper'
+
+module Pronto
+  describe Github do
+    let(:github) { Github.new }
+
+    describe '#commit_comments' do
+      subject { github.commit_comments(repo, sha) }
+
+      context 'three requests for same comments' do
+        let(:repo) { 'mmozuras/pronto' }
+        let(:sha) { '61e4bef' }
+
+        specify do
+          Octokit::Client.any_instance
+                         .should_receive(:commit_comments)
+                         .once
+                         .and_return([])
+
+          subject
+          subject
+          subject
+        end
+      end
+    end
+  end
+end