Improve the Rakefile adding a TaskLib

Author: rafaelfranca

Rakefile

@@ -8,31 +8,36 @@ load "rails/tasks/engine.rake"
 load "rails/tasks/statistics.rake"
 
 require "bundler/gem_tasks"
+require "rake/tasklib"
 
-def databases
-  %w[ mysql postgres sqlite ]
-end
-
-task :test do
-  databases.each do |database|
-    sh("TARGET_DB=#{database} bin/setup")
-    sh("TARGET_DB=#{database} bin/rails test")
+class TestHelpers < Rake::TaskLib
+  def initialize(databases)
+    @databases = databases
+    define
   end
-end
 
-namespace :test do
-  task :mysql do
-    sh("TARGET_DB=mysql bin/setup")
-    sh("TARGET_DB=mysql bin/rails test")
+  def define
+    desc "Run tests for all databases (mysql, postgres, sqlite)"
+    task :test do
+      @databases.each { |database| run_test_for_database(database) }
+    end
+
+    namespace :test do
+      @databases.each do |database|
+        desc "Run tests for #{database} database"
+        task database do
+          run_test_for_database(database)
+        end
+      end
+    end
   end
 
-  task :postgres do
-    sh("TARGET_DB=postgres bin/setup")
-    sh("TARGET_DB=postgres bin/rails test")
-  end
+  private
 
-  task :sqlite do
-    sh("TARGET_DB=sqlite bin/setup")
-    sh("TARGET_DB=sqlite bin/rails test")
+  def run_test_for_database(database)
+    sh("TARGET_DB=#{database} bin/setup")
+    sh("TARGET_DB=#{database} bin/rails test")
   end
 end
+
+TestHelpers.new(%w[ mysql postgres sqlite ])