Update how formatters are registered, allowing the addition of custom formatter

lib/pronto.rb

@@ -35,6 +35,7 @@
 
 require 'pronto/formatter/colorizable'
 require 'pronto/formatter/base'
+require 'pronto/formatter/formatter'
 require 'pronto/formatter/text_formatter'
 require 'pronto/formatter/json_formatter'
 require 'pronto/formatter/git_formatter'
@@ -52,7 +53,6 @@
 require 'pronto/formatter/bitbucket_server_pull_request_formatter'
 require 'pronto/formatter/checkstyle_formatter'
 require 'pronto/formatter/null_formatter'
-require 'pronto/formatter/formatter'
 
 module Pronto
   def self.run(commit = nil, repo_path = '.',

lib/pronto/formatter/base.rb

@@ -2,7 +2,7 @@ module Pronto
   module Formatter
     class Base
       def self.name
-        Formatter::FORMATTERS.invert[self]
+        Formatter::formatters.invert[self]
       end
 
       def config

lib/pronto/formatter/bitbucket_formatter.rb

@@ -15,3 +15,5 @@ def line_number(message, _)
     end
   end
 end
+
+Pronto::Formatter.add('bitbucket', Pronto::Formatter::BitbucketFormatter)

lib/pronto/formatter/bitbucket_pull_request_formatter.rb

@@ -17,11 +17,13 @@ def approve_pull_request(comments_count, additions_count, client)
         return if config.bitbucket_auto_approve == false
 
         if comments_count > 0 && additions_count > 0
-          client.unapprove_pull_request  
+          client.unapprove_pull_request
         elsif comments_count == 0
           client.approve_pull_request
         end
       end
     end
   end
 end
+
+Pronto::Formatter.add('bitbucket_pr', Pronto::Formatter::BitbucketPullRequestFormatter)

lib/pronto/formatter/bitbucket_server_pull_request_formatter.rb

@@ -15,3 +15,5 @@ def line_number(message, _)
     end
   end
 end
+
+Pronto::Formatter.add('bitbucket_server_pr', Pronto::Formatter::BitbucketServerPullRequestFormatter)

lib/pronto/formatter/checkstyle_formatter.rb

@@ -57,3 +57,5 @@ def to_checkstyle_severity(pronto_level)
     end
   end
 end
+
+Pronto::Formatter.add('checkstyle', Pronto::Formatter::CheckstyleFormatter)

lib/pronto/formatter/formatter.rb

@@ -1,30 +1,32 @@
 module Pronto
   module Formatter
-    def self.get(names)
-      names ||= 'text'
-      Array(names).map { |name| FORMATTERS[name.to_s] || TextFormatter }
-        .uniq.map(&:new)
-    end
+    class << self
+      def add(label, formatter_klass = nil)
+        unless formatter_klass.method_defined?(:format)
+          raise NoMethodError, "format method is not declared in the #{label} class."
+        end
 
-    def self.names
-      FORMATTERS.keys
-    end
+        base = Pronto::Formatter::Base
+        raise "#{label.inspect} is not a #{base}" unless formatter_klass.ancestors.include?(base)
+
+        raise ArgumentError, "formatter #{label.inspect} has already been added." if formatters.key?(label)
+
+        formatters[label] = formatter_klass
+      end
 
-    FORMATTERS = {
-      'github' => GithubFormatter,
-      'github_status' => GithubStatusFormatter,
-      'github_combined_status' => GithubCombinedStatusFormatter,
-      'github_pr' => GithubPullRequestFormatter,
-      'github_pr_review' => GithubPullRequestReviewFormatter,
-      'gitlab' => GitlabFormatter,
-      'gitlab_mr' => GitlabMergeRequestReviewFormatter,
-      'bitbucket' => BitbucketFormatter,
-      'bitbucket_pr' => BitbucketPullRequestFormatter,
-      'bitbucket_server_pr' => BitbucketServerPullRequestFormatter,
-      'json' => JsonFormatter,
-      'checkstyle' => CheckstyleFormatter,
-      'text' => TextFormatter,
-      'null' => NullFormatter
-    }.freeze
+      def get(names)
+        names ||= 'text'
+        Array(names).map { |name| formatters[name.to_s] || TextFormatter }
+          .uniq.map(&:new)
+      end
+
+      def names
+        formatters.keys
+      end
+
+      def formatters
+        @formatters ||= {}
+      end
+    end
   end
 end

lib/pronto/formatter/github_combined_status_formatter.rb

@@ -2,7 +2,7 @@
 
 module Pronto
   module Formatter
-    class GithubCombinedStatusFormatter
+    class GithubCombinedStatusFormatter < Base
       def format(messages, repo, _)
         client = Github.new(repo)
         head = repo.head_commit_sha
@@ -22,3 +22,5 @@ def create_status(client, sha, messages)
     end
   end
 end
+
+Pronto::Formatter.add('github_combined_status', Pronto::Formatter::GithubCombinedStatusFormatter)

lib/pronto/formatter/github_formatter.rb

@@ -15,3 +15,5 @@ def line_number(message, _)
     end
   end
 end
+
+Pronto::Formatter.add('github', Pronto::Formatter::GithubFormatter)

lib/pronto/formatter/github_pull_request_formatter.rb

@@ -16,3 +16,5 @@ def line_number(message, patches)
     end
   end
 end
+
+Pronto::Formatter.add('github_pr', Pronto::Formatter::GithubPullRequestFormatter)

lib/pronto/formatter/github_pull_request_review_formatter.rb

@@ -22,3 +22,5 @@ def line_number(message, patches)
     end
   end
 end
+
+Pronto::Formatter.add('github_pr_review', Pronto::Formatter::GithubPullRequestReviewFormatter)

lib/pronto/formatter/github_status_formatter.rb

@@ -2,7 +2,7 @@
 
 module Pronto
   module Formatter
-    class GithubStatusFormatter
+    class GithubStatusFormatter < Base
       def format(messages, repo, _)
         client = Github.new(repo)
         head = repo.head_commit_sha
@@ -26,3 +26,5 @@ def create_status(client, sha, runner, messages)
     end
   end
 end
+
+Pronto::Formatter.add('github_status', Pronto::Formatter::GithubStatusFormatter)

lib/pronto/formatter/github_status_formatter/sentence.rb

@@ -1,6 +1,6 @@
 module Pronto
   module Formatter
-    class GithubStatusFormatter
+    class GithubStatusFormatter < Base
       class Sentence
         def initialize(words)
           @words = words

lib/pronto/formatter/github_status_formatter/status_builder.rb

@@ -2,7 +2,7 @@
 
 module Pronto
   module Formatter
-    class GithubStatusFormatter
+    class GithubStatusFormatter < Base
       class StatusBuilder
         def initialize(runner, messages)
           @runner = runner

lib/pronto/formatter/gitlab_formatter.rb

@@ -15,3 +15,5 @@ def line_number(message, _)
     end
   end
 end
+
+Pronto::Formatter.add('gitlab', Pronto::Formatter::GitlabFormatter)

lib/pronto/formatter/gitlab_merge_request_review_formatter.rb

@@ -27,3 +27,5 @@ def line_number(message, _)
     end
   end
 end
+
+Pronto::Formatter.add('gitlab_mr', Pronto::Formatter::GitlabMergeRequestReviewFormatter)

lib/pronto/formatter/json_formatter.rb

@@ -18,3 +18,5 @@ def format(messages, _repo, _patches)
     end
   end
 end
+
+Pronto::Formatter.add('json', Pronto::Formatter::JsonFormatter)

lib/pronto/formatter/null_formatter.rb

@@ -5,3 +5,5 @@ def format(_messages, _repo, _patches); end
     end
   end
 end
+
+Pronto::Formatter.add('null', Pronto::Formatter::NullFormatter)

lib/pronto/formatter/text_formatter.rb

@@ -13,3 +13,5 @@ def format(messages, _repo, _patches)
     end
   end
 end
+
+Pronto::Formatter.add('text', Pronto::Formatter::TextFormatter)

spec/pronto/formatter/formatter_spec.rb

@@ -1,5 +1,50 @@
 module Pronto
   module Formatter
+    describe '.add' do
+      context 'format method not implementend' do
+        subject { Formatter.add(formatter_label, formatter) }
+
+        let(:formatter_label) { 'formatter_without_method' }
+        let(:formatter) { Class.new(Pronto::Formatter::Base) }
+
+        specify do
+          -> { subject }.should raise_error(
+            NoMethodError, "format method is not declared in the #{formatter_label} class."
+          )
+        end
+      end
+
+      context 'formatter class is not Formatter::Base' do
+        subject { Formatter.add(formatter_label, formatter) }
+
+        let(:formatter_label) { 'formatter_without_base_class' }
+        let(:formatter) do
+          Class.new do
+            def format(_messages, _repo, _patches); end
+          end
+        end
+
+        specify do
+          -> { subject }.should raise_error("#{formatter_label.inspect} is not a #{Pronto::Formatter::Base}")
+        end
+      end
+
+      context 'there is a formater with same name' do
+        subject { Formatter.add(formatter_label, formatter) }
+
+        let(:formatter_label) { 'json' }
+        let(:formatter) do
+          Class.new(Pronto::Formatter::Base) do
+            def format(_messages, _repo, _patches); end
+          end
+        end
+
+        specify do
+          -> { subject }.should raise_error("formatter #{formatter_label.inspect} has already been added.")
+        end
+      end
+    end
+
     describe '.get' do
       context 'single' do
         subject { Formatter.get(name).first }