Formatter for GitHub pull requests

Closes #16

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### New features
 
 * [#27](https://github.com/mmozuras/pronto/issues/27): '--exit-code' option for 'pronto run'. Pronto exits with non-zero code if there were any warnings/errors.
+* [#16](https://github.com/mmozuras/pronto/issues/16): New formatter: GithubPullRequestFormatter. Writes review comments on GitHub pull requests.
 
 ### Changes
 

lib/pronto.rb

@@ -16,6 +16,7 @@
 require 'pronto/formatter/text_formatter'
 require 'pronto/formatter/json_formatter'
 require 'pronto/formatter/github_formatter'
+require 'pronto/formatter/github_pull_request_formatter'
 require 'pronto/formatter/checkstyle_formatter'
 require 'pronto/formatter/formatter'
 

lib/pronto/formatter/formatter.rb

@@ -11,6 +11,7 @@ def self.names
 
     FORMATTERS = {
       'github' => GithubFormatter,
+      'github_pr' => GithubPullRequestFormatter,
       'json' => JsonFormatter,
       'checkstyle' => CheckstyleFormatter,
       'text' => TextFormatter

lib/pronto/formatter/github_formatter.rb

@@ -5,9 +5,9 @@ def format(messages, repo)
         commit_messages = messages.map do |message|
           github_slug = repo.github_slug
           sha = message.commit_sha
-          position = message.line.commit_line.position if message.line
           body = message.msg
           path = message.path
+          position = message.line.commit_line.position if message.line
 
           comment = Github::Comment.new(github_slug, sha, body, path, position)
           create_comment(github_slug, sha, comment)

lib/pronto/formatter/github_pull_request_formatter.rb

@@ -0,0 +1,41 @@
+module Pronto
+  module Formatter
+    class GithubPullRequestFormatter
+      def format(messages, repo)
+        commit_messages = messages.map do |message|
+          github_slug = repo.github_slug
+          body = message.msg
+          path = message.path
+
+          commits = repo.commits_until(message.commit_sha)
+
+          line = nil
+          sha = commits.find do |commit|
+            patches = repo.show_commit(commit)
+            line = patches.find_line(message.full_path, message.line.new_lineno)
+            line
+          end
+
+          position = line.position - 1
+
+          comment = Github::Comment.new(github_slug, sha, body, path, position)
+          create_comment(github_slug, sha, comment)
+        end
+
+        "#{commit_messages.compact.count} Pronto messages posted to GitHub"
+      end
+
+      private
+
+      def create_comment(repo, sha, comment)
+        comments = client.pull_comments(repo, sha)
+        existing = comments.any? { |c| comment == c }
+        client.create_pull_comment(repo, sha, comment) unless existing
+      end
+
+      def client
+        @client ||= Github.new
+      end
+    end
+  end
+end

lib/pronto/git/repository.rb

@@ -30,6 +30,15 @@ def show_commit(sha)
         Patches.new(self, sha, diff.patches)
       end
 
+      def commits_until(sha)
+        result = []
+        @repo.walk('HEAD', Rugged::SORT_TOPO).take_while do |commit|
+          result << commit.oid
+          !commit.oid.start_with?(sha)
+        end
+        result
+      end
+
       def path
         Pathname.new(@repo.path).parent
       end

lib/pronto/github.rb

@@ -4,6 +4,14 @@ def initialize
       @comment_cache = {}
     end
 
+    def pull_comments(repo, sha)
+      @comment_cache["#{repo}/#{pull_id}/#{sha}"] ||= begin
+        client.pull_comments(repo, pull_id).map do |comment|
+          Comment.new(repo, sha, comment.body, comment.path, comment.body)
+        end
+      end
+    end
+
     def commit_comments(repo, sha)
       @comment_cache["#{repo}/#{sha}"] ||= begin
         client.commit_comments(repo, sha).map do |comment|
@@ -17,12 +25,21 @@ def create_commit_comment(repo, sha, comment)
                                    nil, comment.position)
     end
 
+    def create_pull_comment(repo, sha, comment)
+      client.create_pull_comment(repo, pull_id, comment.body, sha, comment.path,
+                                 comment.position)
+    end
+
     private
 
     def client
       @client ||= Octokit::Client.new(access_token: access_token)
     end
 
+    def pull_id
+      ENV['PULL_REQUEST_ID'].to_i
+    end
+
     def access_token
       ENV['GITHUB_ACCESS_TOKEN']
     end

lib/pronto/message.rb

@@ -17,6 +17,10 @@ def initialize(path, line, level, msg, commit_sha = nil)
       @commit_sha ||= line.commit_sha if line
     end
 
+    def full_path
+      repo.path.join(path) if repo
+    end
+
     def repo
       line.patch.repo if line
     end

spec/pronto/formatter/formatter_spec.rb

@@ -10,6 +10,11 @@ module Formatter
         it { should be_an_instance_of GithubFormatter }
       end
 
+      context 'github_pr' do
+        let(:name) { 'github_pr' }
+        it { should be_an_instance_of GithubPullRequestFormatter }
+      end
+
       context 'json' do
         let(:name) { 'json' }
         it { should be_an_instance_of JsonFormatter }
@@ -38,7 +43,7 @@ module Formatter
 
     describe '.names' do
       subject { Formatter.names }
-      it { should =~ %w(github json checkstyle text) }
+      it { should =~ %w(github github_pr json checkstyle text) }
     end
   end
 end

spec/pronto/git/patch_spec.rb

@@ -35,7 +35,7 @@ module Git
         let(:rugged_patch) do
           double(delta: double(new_file: { path: 'test.md' }))
         end
-        let(:repo) { double(path: '/house/of/cards/orig.md') }
+        let(:repo) { double(path: Pathname.new('/house/of/cards')) }
         its(:to_s) { should == '/house/of/cards/test.md' }
       end
     end