feat: Setup configuration

Author: hapiben

.rubocop.yml

@@ -11,3 +11,6 @@ Style/StringLiteralsInInterpolation:
 
 Layout/LineLength:
   Max: 120
+
+Style/Documentation:
+  Enabled: false

Gemfile.lock

@@ -49,6 +49,7 @@ GEM
     unicode-display_width (2.3.0)
 
 PLATFORMS
+  ruby
   x86_64-darwin-19
 
 DEPENDENCIES

README.md

@@ -101,6 +101,21 @@ NOTE: similar code will only work correctly if you run a diff on all the files i
     ```
 4. Now you have time to fix the issues yay!
 
+## Configuration
+
+Example: 
+
+```rb
+CodeclimateDiff.configure do |config|
+  config.gitlab = {
+    main_branch_name: "main", # Required. Defaults to "main"
+    project_id: 123, # Required. Gitlab's Project ID. Defaults nil.
+    host: "https://org.gitlab.org", # Required. Gitlab's Host. e.g. https://org.gitlab.org. Defaults nil.
+    personal_access_token: ENV["GITLAB_PERSONAL_ACCESS_TOKEN"] # Required. Your personal access token. Defaults nil.
+  }
+end
+```
+
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.

lib/codeclimate_diff.rb

@@ -1,7 +1,16 @@
 # frozen_string_literal: true
 
 require_relative "codeclimate_diff/version"
+require_relative "codeclimate_diff/configuration"
 
 module CodeclimateDiff
-  
+  class << self
+    def configuration
+      @configuration ||= Configuration.new
+    end
+
+    def configure
+      yield(configuration)
+    end
+  end
 end

lib/codeclimate_diff/configuration.rb

@@ -2,13 +2,15 @@
 
 module CodeclimateDiff
   class Configuration
-    attr_accessor :main_branch_name
-
-    #using_gitlab: true
-
-    # gitlab host
-
-    # project id
+    attr_accessor :gitlab
 
+    def initialize
+      @gitlab = {
+        main_branch_name: "main",
+        project_id: nil,
+        host: nil,
+        personal_access_token: nil
+      }
+    end
   end
 end