Refactored JSON header generation to its own class and added tests for it

lib/gitlab_lfs_authentication.rb

+require 'base64'
+require 'json'
+
+class GitlabLfsAuthentication
+  attr_accessor :user, :repository_http_path
+
+  def initialize(user, repository_http_path)
+    @user = user
+    @repository_http_path = repository_http_path
+  end
+
+  def authenticate!
+    authorization = {
+      header: {
+        Authorization: "Basic #{Base64.strict_encode64("#{user['username']}:#{user['lfs_token']}")}"
+      },
+      href: "#{repository_http_path}/info/lfs/"
+    }
+
+    JSON.generate(authorization)
+  end
+end

lib/gitlab_shell.rb

 require 'shellwords'
-require 'base64'
-require 'json'
 
 require_relative 'gitlab_net'
+require_relative 'gitlab_lfs_authentication'
 
 class GitlabShell
   class AccessDeniedError < StandardError; end
@@ -195,14 +194,7 @@ class GitlabShell
   def lfs_authenticate
     return unless user
 
-    authorization = {
-      header: {
-        Authorization: "Basic #{Base64.strict_encode64("#{user['username']}:#{user['lfs_token']}")}"
-      },
-      href: "#{repository_http_path}/info/lfs/"
-    }
-
-    puts JSON.generate(authorization)
+    puts GitlabLfsAuthentication.new(user, repository_http_path).authenticate!
   end
 
   private

spec/gitlab_lfs_authentication_spec.rb

+require 'spec_helper'
+require 'gitlab_lfs_authentication'
+
+describe GitlabLfsAuthentication do
+  let(:user) { { 'username' => 'dzaporozhets', 'lfs_token' => 'wsnys8Zm8Jn7zyhHTAAK' } }
+
+  subject do
+    GitlabLfsAuthentication.new(user, 'http://gitlab.dev/repo')
+  end
+
+  describe '#initialize' do
+    it { subject.user.should == user }
+    it { subject.repository_http_path.should == 'http://gitlab.dev/repo' }
+  end
+
+  describe '#authenticate!' do
+    result = "{\"header\":{\"Authorization\":\"Basic ZHphcG9yb3poZXRzOndzbnlzOFptOEpuN3p5aEhUQUFL\"},\"href\":\"http://gitlab.dev/repo/info/lfs/\"}"
+
+    it { subject.authenticate!.should == result }
+  end
+end