diff --git a/all_tests.cfg.erb b/all_tests.cfg.erb
deleted file mode 100755
--- a/all_tests.cfg.erb
+++ /dev/null
@@ -1,13 +0,0 @@
-problem do
-  num_tests <%= num_testcases %>
-  full_score <%= num_testcases*10 %>
-  time_limit_each <%= options[:time_limit] %>
-  mem_limit_each <%= options[:mem_limit] %>
-  score_each 10
-
-<% 1.upto(num_testcases) do |i| %>
-  run <%= i %> do
-    tests <%= i %>
-  end
-<% end %>
-end
diff --git a/config/env_exam.rb.SAMPLE b/config/env_exam.rb.SAMPLE
--- a/config/env_exam.rb.SAMPLE
+++ b/config/env_exam.rb.SAMPLE
@@ -1,20 +1,20 @@
-
-
+#
+# See documentation in lib/configuration.rb
+#
 Grader::Initializer.run do |config|
 
-  config.problems_dir = "/home/jittat/grader/ev"
-  config.user_result_dir = "/home/jittat/grader/result"
+  config.problems_dir = GRADER_ROOT + "/../ev"
+  config.user_result_dir = GRADER_ROOT + "/../result"
   
   config.talkative = true
+  config.logging = true
+  config.log_dir = GRADER_ROOT + "/../log"
   
   config.report_grader = true
-  
-  config.report_comment = lambda do |comment|	
-    if comment.chomp =~ /^P+$/    # all P's
-      'passed'
-    else
-      'failed'
-    end
-  end
-  
+ 
+  config.test_request_input_base_dir = RAILS_ROOT + "/data/test_request/input"
+  config.test_request_output_base_dir = RAILS_ROOT + "/data/test_request/output"
+  config.test_request_problem_templates_dir = config.problems_dir + "/test_request"
+ 
+  config.comment_report_style = :short
 end
diff --git a/config/env_grading.rb.SAMPLE b/config/env_grading.rb.SAMPLE
--- a/config/env_grading.rb.SAMPLE
+++ b/config/env_grading.rb.SAMPLE
@@ -1,16 +1,19 @@
-
-
+#
+# See documentation in lib/configuration.rb
+#
 Grader::Initializer.run do |config|
-
-  config.problems_dir = "/home/jittat/grader/ev"
-  config.user_result_dir = "/home/jittat/grader/result"
+  config.problems_dir = GRADER_ROOT + "/../ev"
+  config.user_result_dir = GRADER_ROOT + "/../result"
   
   config.talkative = true
+  config.logging = true
+  config.log_dir = GRADER_ROOT + "/../log"
   
   config.report_grader = true
   
-  config.report_comment = lambda do |comment|	
-    comment.chomp
-  end
-  
+  config.test_request_input_base_dir = RAILS_ROOT + "/data/test_request/input"
+  config.test_request_output_base_dir = RAILS_ROOT + "/data/test_request/output"
+  config.test_request_problem_templates_dir = config.problems_dir + "/test_request"
+ 
+  config.comment_report_style = :full
 end
diff --git a/config/env_test.rb.SAMPLE b/config/env_test.rb.SAMPLE
--- a/config/env_test.rb.SAMPLE
+++ b/config/env_test.rb.SAMPLE
@@ -1,25 +1,29 @@
-
-
+#
+# See documentation in lib/configuration.rb
+#
 Grader::Initializer.run do |config|
+  config.problems_dir = GRADER_ROOT + "/test/sandbox/ev"
+  config.user_result_dir = GRADER_ROOT + "/test/sandbox/result"
   
-  config.problems_dir = "/home/jittat/grader/scripts/test/sandbox/ev"
-  config.user_result_dir = "/home/jittat/grader/scripts/test/sandbox/result"
-  
-  config.talkative = true
+  config.talkative = false
   
   config.report_grader = false
 
   config.rails_env = 'test'
   
-  config.report_comment = lambda do |comment|	
-    comment.chomp
-  end
+  config.comment_report_style = :full
 
+  config.test_request_input_base_dir = GRADER_ROOT + "/test/data/test_request/input"
+  config.test_request_output_base_dir = GRADER_ROOT + "/test/sandbox/test_request/output"
+  config.test_request_problem_templates_dir = GRADER_ROOT + "/test/data/test_request/problems"
+
+  #
+  # These options are for testing
+  #
   class << config
     attr_accessor :test_data_dir, :test_sandbox_dir
   end
 
-  config.test_data_dir = "/home/jittat/grader/scripts/test/data"
-  config.test_sandbox_dir = "/home/jittat/grader/scripts/test/sandbox"
-
+  config.test_data_dir = GRADER_ROOT + "/test/data"
+  config.test_sandbox_dir = GRADER_ROOT + "/test/sandbox"
 end
diff --git a/config/environment.rb.SAMPLE b/config/environment.rb.SAMPLE
--- a/config/environment.rb.SAMPLE
+++ b/config/environment.rb.SAMPLE
@@ -1,11 +1,10 @@
-
 # Rails app directory
 RAILS_ROOT = "/home/jittat/web_grader"
 
 GRADER_ROOT = "/home/jittat/grader/scripts"
 
+# This load all required codes
 require File.join(File.dirname(__FILE__),'../lib/boot')
 
 # load the required environment file
 require File.dirname(__FILE__) + "/env_#{GRADER_ENV}.rb"
-
diff --git a/grader b/grader
--- a/grader
+++ b/grader
@@ -16,16 +16,46 @@
   Grader::Configuration.get_instance
 end
 
-def talk(str)
+def log_file_name
+  config.log_dir + 
+    "/#{GRADER_ENV}_#{config.grader_mode}.#{Process.pid}"
+end
+
+def log(str)
   if config.talkative
     puts str
   end
+  if config.logging
+    fp = File.open(log_file_name,"a")
+    fp.puts("GRADER: #{Time.new.strftime("%H:%M")} #{str}")
+    fp.close
+  end
+end
+
+def display_manual
+  puts <<USAGE
+Grader.
+using: (1) grader 
+       (2) grader environment [mode]
+       (3) grader stop
+       (4) grader --help
+(1) call grader with environment = 'exam', mode = 'queue'
+(2) possible modes are: 'queue', 'prob', 'test_request'
+(3) create stop-file to stop running grader in queue mode
+(4) You are here.
+USAGE
 end
 
 #########################################
 # main program
 #########################################
 
+# with --help
+if (ARGV.length==1) and (/help/.match(ARGV[0]))
+  display_manual
+  exit(0)
+end
+
 # reading environment and options
 if (ARGV.length >= 1) and (ARGV[0]=='stop')
   stop_grader
@@ -52,14 +82,20 @@
 puts "environment: #{GRADER_ENV}"
 require File.join(File.dirname(__FILE__),'config/environment')
 
-#reading rails environment
-talk 'Reading rails environment'
+# add grader_mode to config
+# this is needed because method log needs it.  TODO: clean this up
+class << config
+  attr_accessor :grader_mode
+end
+config.grader_mode = grader_mode
+
+# reading rails environment
+log 'Reading rails environment'
 
 RAILS_ENV = config.rails_env
 require RAILS_ROOT + '/config/environment'
 
-
-#register grader process
+# register grader process
 if config.report_grader
   grader_proc = GraderProcess.register(config.grader_hostname,
                                        Process.pid,
@@ -68,27 +104,45 @@
   grader_proc = nil
 end
 
-# create judge engine
-engine = Grader::Engine.new(grader_proc)
+#set loggin environment
+ENV['GRADER_LOGGING'] = log_file_name
+
+#
+# MAIN LOOP
+#
 
 case grader_mode
-when "queue"
-  talk 'Grader queue'
+when "queue", "test_request"
+  log "Grader: #{grader_mode}"
+  if grader_mode=="queue"
+    engine = Grader::Engine.new
+  else
+    engine = Grader::Engine.new(Grader::TestRequestRoomMaker.new,
+                                Grader::TestRequestReporter.new)
+  end
+
+  runner = Grader::Runner.new(engine, grader_proc)
   while true
     
     if check_stopfile    # created by calling grader stop
       clear_stopfile
-      puts "stopped"
+      log "stopped (with stop file)"
       break
     end
-
-    task = engine.grade_oldest_task
+    
+    if grader_mode=="queue"
+      task = runner.grade_oldest_task
+    else
+      task = runner.grade_oldest_test_request
+    end
     if task==nil
-      sleep(5)
+      sleep(1)
     end
   end
   
 when "prob"
+  engine = Grader::Engine.new
+  runner = Grader::Runner.new(engine, grader_proc)
 
   grader_proc.report_active if grader_proc!=nil
 
@@ -96,9 +150,12 @@
   if prob==nil
     puts "cannot find problem: #{ARGV[2]}"
   else
-    engine.grade_problem(prob)
+    runner.grade_problem(prob)
   end
-  
+
+else
+  display_manual
+  exit(0)
 end
 
 # report inactive
diff --git a/import_problem b/import_problem
--- a/import_problem
+++ b/import_problem
@@ -5,6 +5,7 @@
 #  * copy testdata in the old format and create standard testcase config file
 
 require 'erb'
+require 'fileutils'
 
 def input_filename(dir,i)
   "#{dir}/input-#{i}.txt"
@@ -34,15 +35,18 @@
   end
 end
 
-GRADER_DIR = File.dirname(__FILE__)
+SCRIPT_DIR = File.dirname(__FILE__)
 
 # print usage
 if ARGV.length < 3
-  puts "using: import_problem prob_name importing_testcase_dir num_of_testcase [options]
+  puts <<USAGE
+using: import_problem prob_name importing_testcase_dir num_of_testcase [options]
   * creates a directory for a problem in the current directory,
   * copy testdata in the old format and create standard testcase config file
+  * creates a test_request template in the current directory + '/test_request'
   * options: -t time-limit (in seconds)
-             -m memory-limit (in megabytes)"
+             -m memory-limit (in megabytes)
+USAGE
   exit(127)
 end
 
@@ -57,6 +61,7 @@
 # start working
 puts "creating directories"
 
+
 system("mkdir #{problem}")
 system("mkdir #{problem}/script")
 system("mkdir #{problem}/test_cases")
@@ -73,11 +78,26 @@
 # generating all_tests.cfg
 puts "generating testcase config file"
 
-template = File.open(File.dirname(__FILE__) + "/all_tests.cfg.erb").read
+template = File.open(SCRIPT_DIR + "/templates/all_tests.cfg.erb").read
 all_test_cfg = ERB.new(template)
 
 cfg_file = File.open("#{problem}/test_cases/all_tests.cfg","w")
 cfg_file.puts all_test_cfg.result
 cfg_file.close
 
+# generating test_request directory
+puts "generating test_request template"
+FileUtils.mkdir_p("test_request/#{problem}/script")
+FileUtils.mkdir_p("test_request/#{problem}/test_cases/1")
+
+template = File.open(SCRIPT_DIR + "/templates/test_request_all_tests.cfg.erb").read
+test_request_all_test_cfg = ERB.new(template)
+
+cfg_file = File.open("test_request/#{problem}/test_cases/all_tests.cfg","w")
+cfg_file.puts test_request_all_test_cfg.result
+cfg_file.close
+
+system("cp #{SCRIPT_DIR}/templates/check_empty test_request/#{problem}/script/check")
+system("cp #{SCRIPT_DIR}/templates/answer-1.txt test_request/#{problem}/test_cases/1")
+
 puts "done"
diff --git a/lib/boot.rb b/lib/boot.rb
--- a/lib/boot.rb
+++ b/lib/boot.rb
@@ -1,5 +1,10 @@
 
 require File.join(File.dirname(__FILE__), 'configuration')
 require File.join(File.dirname(__FILE__), 'initializer')
+
+require File.join(File.dirname(__FILE__), 'submission_helper')
+require File.join(File.dirname(__FILE__), 'test_request_helper')
+
 require File.join(File.dirname(__FILE__), 'engine')
+require File.join(File.dirname(__FILE__), 'runner')
 
diff --git a/lib/configuration.rb b/lib/configuration.rb
--- a/lib/configuration.rb
+++ b/lib/configuration.rb
@@ -1,17 +1,60 @@
-
 module Grader
 
+  # This singleton class holds basic configurations for grader.  When
+  # running in each mode, grader uses resources from different
+  # directories and outputs differently.  Usually the attributes name
+  # are descriptive; below we explain more on each attributes.
   class Configuration
+    # Rails' environment: "development", "production"
+    attr_accessor :rails_env
 
-    private_class_method :new
-
+    # Grader looks for problem [prob] in problem_dir/[prob], and store
+    # execution results for submission [x] of user [u] in directory
+    # user_result_dir/[u]/[x]
     attr_accessor :problems_dir
     attr_accessor :user_result_dir
-    attr_accessor :talkative
+
+    # If report_grader=true, the grader would add a row in model
+    # GraderProcess.  It would report itself with grader_hostname and
+    # process id.
     attr_accessor :report_grader
     attr_accessor :grader_hostname    
-    attr_accessor :report_comment
-    attr_accessor :rails_env
+
+    # If talkative=true, grader would report status to console.  If
+    # logging=true, grader would report status to a log file located
+    # in log_dir, in a file name mode.options.pid.  TODO: defined
+    # log file naming.
+    attr_accessor :talkative
+    attr_accessor :logging
+    attr_accessor :log_dir
+
+    # These are directories related to the test interface.
+    attr_accessor :test_request_input_base_dir
+    attr_accessor :test_request_output_base_dir
+    attr_accessor :test_request_problem_templates_dir
+
+    # Comment received from the grading script will be filtered
+    # through Configuration#report_comment.  How this method behave
+    # depends on this option; right now only two formats, :short and
+    # :long
+    attr_accessor :comment_report_style
+
+    def report_comment(comment)
+      case comment_report_style
+      when :short
+        if comment.chomp =~ /^P+$/    # all P's
+          'passed'
+        else
+          'failed'
+        end
+        
+      when :full
+        comment.chomp
+      end
+    end
+
+    # Codes for singleton
+    private_class_method :new
 
     @@instance = nil
 
@@ -25,12 +68,13 @@
     private
     def initialize
       @talkative = false
+      @log_file = nil
       @report_grader = false
       @grader_hostname = `hostname`.chomp
 
       @rails_env = 'development'
       
-      @report_comment = lambda { |comment| comment }
+      @comment_report_style = :full
     end
 
   end
diff --git a/lib/engine.rb b/lib/engine.rb
--- a/lib/engine.rb
+++ b/lib/engine.rb
@@ -1,80 +1,78 @@
+require 'fileutils'
 
 module Grader
 
+  #
+  # A grader engine grades a submission, against anything: a test
+  # data, or a user submitted test data.  It uses two helpers objects:
+  # room_maker and reporter.
+  #
   class Engine
+    
+    attr_writer :room_maker
+    attr_writer :reporter
 
-    def initialize(grader_process=nil)
+    def initialize(room_maker=nil, reporter=nil)
       @config = Grader::Configuration.get_instance
-      @grader_process = grader_process
+
+      @room_maker = room_maker || Grader::SubmissionRoomMaker.new 
+      @reporter = reporter || Grader::SubmissionReporter.new
     end
-
-    def grade(sub)
+    
+    # takes a submission, asks room_maker to produce grading directories,
+    # calls grader scripts, and asks reporter to save the result
+    def grade(submission)
       current_dir = `pwd`.chomp
 
-      submission_id = sub.id
-      user = sub.user
-      problem = sub.problem
+      user = submission.user
+      problem = submission.problem
 
       # TODO: will have to create real exception for this
-      raise "improper submission" if user==nil or problem==nil
+      if user==nil or problem == nil
+        @reporter.report_error(submission,"Grading error: problem with submission")
+        #raise "engine: user or problem is nil"
+      end
       
-      language = sub.language.name
-      lang_ext = sub.language.ext
+      language = submission.language.name
+      lang_ext = submission.language.ext
       # FIX THIS
       talk 'some hack on language'
       if language == 'cpp'
         language = 'c++'
       end
 
-      user_dir = "#{@config.user_result_dir}/#{user.login}"
-      problem_out_dir = "#{user_dir}/#{problem.name}"
-      submission_out_dir = "#{user_dir}/#{problem.name}/#{submission_id}"
-
-      mkdir_if_does_not_exist(user_dir)
-      mkdir_if_does_not_exist(problem_out_dir)
-      mkdir_if_does_not_exist(submission_out_dir)
+      # COMMENT: should it be only source.ext?
+      if problem!=nil
+        source_name = "#{problem.name}.#{lang_ext}"
+      else
+        source_name = "source.#{lang_ext}"
+      end
 
-      problem_home = "#{@config.problems_dir}/#{problem.name}"
-      source_name = "#{problem.name}.#{lang_ext}"
-      
-      save_source(sub,submission_out_dir,source_name)
-      
-      copy_log = copy_script(problem_home)
-      
-      call_judge(problem_home,language,submission_out_dir,source_name)
-      save_result(sub,read_result("#{submission_out_dir}/test-result"))
-      
-      clear_script(copy_log,problem_home)
-      
-      Dir.chdir(current_dir)
-    end
+      begin
+        grading_dir = @room_maker.produce_grading_room(submission)
+        @room_maker.save_source(submission,source_name)
+        problem_home = @room_maker.find_problem_home(submission)
+
+        # puts "GRADING DIR: #{grading_dir}"
+        # puts "PROBLEM DIR: #{problem_home}"
 
-    def grade_oldest_task
-      task = Task.get_inqueue_and_change_status(Task::STATUS_GRADING)
-      if task!=nil 
-        @grader_process.report_active(task) if @grader_process!=nil
-    
-        submission = Submission.find(task.submission_id)
-        grade(submission)
-        task.status_complete!
-      end
-      return task
-    end
+        copy_log = copy_script(problem_home)
+      
+        call_judge(problem_home,language,grading_dir,source_name)
+
+        @reporter.report(submission,"#{grading_dir}/test-result")
 
-    def grade_problem(problem)
-      users = User.find(:all)
-      users.each do |u|
-        puts "user: #{u.login}"
-        last_sub = Submission.find(:first,
-                                   :conditions => "user_id = #{u.id} and " +
-                                                  "problem_id = #{prob.id}",
-                                   :order => 'submitted_at DESC')
-        if last_sub!=nil
-          grade(last_sub)
-        end
+        clear_script(copy_log,problem_home)
+
+      rescue RuntimeError => msg
+        @reporter.report_error(submission,"Grading error: #{msg}")
+
+      ensure
+        @room_maker.clean_up(submission)
+        Dir.chdir(current_dir)   # this is really important
       end
     end
-
+    
     protected
     
     def talk(str)
@@ -83,66 +81,16 @@
       end
     end
 
-    def save_source(submission,dir,fname)
-      f = File.open("#{dir}/#{fname}","w")
-      f.write(submission.source)
-      f.close
-    end
-
-    def call_judge(problem_home,language,submission_out_dir,fname)
+    def call_judge(problem_home,language,grading_dir,fname)
       ENV['PROBLEM_HOME'] = problem_home
       
-      talk submission_out_dir
-      Dir.chdir submission_out_dir
+      talk grading_dir
+      Dir.chdir grading_dir
       cmd = "#{problem_home}/script/judge #{language} #{fname}"
       talk "CMD: #{cmd}"
       system(cmd)
     end
 
-    def read_result(test_result_dir)
-      cmp_msg_fname = "#{test_result_dir}/compiler_message"
-      cmp_file = File.open(cmp_msg_fname)
-      cmp_msg = cmp_file.read
-      cmp_file.close
-      
-      result_fname = "#{test_result_dir}/result"
-      comment_fname = "#{test_result_dir}/comment"  
-      if FileTest.exist?(result_fname)
-        result_file = File.open(result_fname)
-        result = result_file.readline.to_i
-        result_file.close
-        
-        comment_file = File.open(comment_fname)
-        comment = comment_file.readline.chomp
-        comment_file.close
-        
-        return {:points => result, 
-          :comment => comment, 
-          :cmp_msg => cmp_msg}
-      else
-        return {:points => 0,
-          :comment => 'compile error',
-          :cmp_msg => cmp_msg}
-      end
-    end
-    
-    def save_result(submission,result)
-      problem = submission.problem
-      submission.graded_at = Time.now
-      points = result[:points]
-      submission.points = points
-      comment = @config.report_comment.call(result[:comment])
-      if problem == nil
-        submission.grader_comment = 'PASSED: ' + comment + '(problem is nil)'
-      elsif points == problem.full_score
-        submission.grader_comment = 'PASSED: ' + comment
-      else
-        submission.grader_comment = 'FAILED: ' + comment
-      end
-      submission.compiler_message = result[:cmp_msg]
-      submission.save
-    end
-    
     def get_std_script_dir
       GRADER_ROOT + '/std-script'
     end
diff --git a/lib/runner.rb b/lib/runner.rb
new file mode 100644
--- /dev/null
+++ b/lib/runner.rb
@@ -0,0 +1,54 @@
+#
+# A runner drives the engine into various tasks.
+# 
+
+module Grader
+
+  class Runner
+
+    def initialize(engine, grader_process=nil)
+      @engine = engine
+      @grader_process = grader_process
+    end
+
+    def grade_oldest_task
+      task = Task.get_inqueue_and_change_status(Task::STATUS_GRADING)
+      if task!=nil 
+        @grader_process.report_active(task) if @grader_process!=nil
+        
+        submission = Submission.find(task.submission_id)
+        @engine.grade(submission)
+        task.status_complete!
+      end
+      return task
+    end
+
+    def grade_problem(problem)
+      users = User.find(:all)
+      users.each do |u|
+        puts "user: #{u.login}"
+        last_sub = Submission.find(:first,
+                                   :conditions => "user_id = #{u.id} and " +
+                                                  "problem_id = #{prob.id}",
+                                   :order => 'submitted_at DESC')
+        if last_sub!=nil
+          @engine.grade(last_sub)
+        end
+      end
+    end
+
+    def grade_oldest_test_request
+      test_request = TestRequest.get_inqueue_and_change_status(Task::STATUS_GRADING)
+      if test_request!=nil 
+        @grader_process.report_active(test_request) if @grader_process!=nil
+        
+        @engine.grade(test_request)
+        test_request.status_complete!
+      end
+      return test_request
+    end
+
+  end
+
+end
+
diff --git a/lib/submission_helper.rb b/lib/submission_helper.rb
new file mode 100644
--- /dev/null
+++ b/lib/submission_helper.rb
@@ -0,0 +1,95 @@
+module Grader
+
+  class SubmissionRoomMaker
+    def initialize
+      @config = Grader::Configuration.get_instance
+    end
+    
+    def produce_grading_room(submission)
+      user = submission.user
+      problem = submission.problem
+      grading_room = "#{@config.user_result_dir}/" + 
+        "#{user.login}/#{problem.name}/#{submission.id}"
+      
+      FileUtils.mkdir_p(grading_room)
+      grading_room
+    end
+    
+    def find_problem_home(submission)
+      problem = submission.problem
+      "#{@config.problems_dir}/#{problem.name}"
+    end
+
+    def save_source(submission,source_name)
+      dir = self.produce_grading_room(submission)
+      f = File.open("#{dir}/#{source_name}","w")
+      f.write(submission.source)
+      f.close
+    end
+
+    def clean_up(submission)
+    end
+  end
+  
+  class SubmissionReporter
+    def initialize
+      @config = Grader::Configuration.get_instance
+    end
+    
+    def report(sub,test_result_dir)
+      save_result(sub,read_result(test_result_dir))
+    end
+    
+    def report_error(sub,msg)
+      save_result(sub,{:points => 0,
+                    :comment => "Grading error: #{msg}" })
+    end
+
+    protected
+    def read_result(test_result_dir)
+      cmp_msg_fname = "#{test_result_dir}/compiler_message"
+      cmp_file = File.open(cmp_msg_fname)
+      cmp_msg = cmp_file.read
+      cmp_file.close
+      
+      result_fname = "#{test_result_dir}/result"
+      comment_fname = "#{test_result_dir}/comment"  
+      if FileTest.exist?(result_fname)
+        result_file = File.open(result_fname)
+        result = result_file.readline.to_i
+        result_file.close
+        
+        comment_file = File.open(comment_fname)
+        comment = comment_file.readline.chomp
+        comment_file.close
+        
+        return {:points => result, 
+          :comment => comment, 
+          :cmp_msg => cmp_msg}
+      else
+        return {:points => 0,
+          :comment => 'compile error',
+          :cmp_msg => cmp_msg}
+      end
+    end
+    
+    def save_result(submission,result)
+      problem = submission.problem
+      submission.graded_at = Time.now
+      points = result[:points]
+      submission.points = points
+      comment = @config.report_comment(result[:comment])
+      if problem == nil
+        submission.grader_comment = 'PASSED: ' + comment + '(problem is nil)'
+      elsif points == problem.full_score
+        submission.grader_comment = 'PASSED: ' + comment
+      else
+        submission.grader_comment = 'FAILED: ' + comment
+      end
+      submission.compiler_message = result[:cmp_msg] or ''
+      submission.save
+    end
+    
+  end
+  
+end
diff --git a/lib/test_request_helper.rb b/lib/test_request_helper.rb
new file mode 100644
--- /dev/null
+++ b/lib/test_request_helper.rb
@@ -0,0 +1,190 @@
+#
+# This part contains various test_request helpers for interfacing
+# with Grader::Engine.  There are TestRequestRoomMaker and
+# TestRequestReporter.
+
+module Grader
+
+  #
+  # A TestRequestRoomMaker is a helper object for Engine
+  # - finds grading room: in user_result_dir/(user)/test_request/ ...
+  # - prepare problem configuration for grading --- basically it copy
+  #   all config files, and copy user's input into the testcase
+  #   directory.  First, it finds the template from problem template
+  #   directory; if it can't find a template, it'll use the template
+  #   from default template.
+  class TestRequestRoomMaker
+    def initialize
+      @config = Grader::Configuration.get_instance
+    end
+    
+    def produce_grading_room(test_request)
+      grading_room = grading_room_dir(test_request)
+      FileUtils.mkdir_p(grading_room)
+      grading_room
+    end
+    
+    def find_problem_home(test_request)
+      problem_name = test_request.problem_name
+
+      template_dir = "#{@config.test_request_problem_templates_dir}/" + problem_name
+
+      raise "Test Request: error template not found" if !File.exists?(template_dir)
+      
+      problem_home = problem_home_dir(test_request)
+      FileUtils.mkdir_p(problem_home)
+      
+      copy_problem_template(template_dir,problem_home)
+      link_input_file(test_request,problem_home)
+
+      problem_home
+    end
+    
+    def save_source(test_request,source_name)
+      dir = self.produce_grading_room(test_request)
+      submission = test_request.submission
+      f = File.open("#{dir}/#{source_name}","w")
+      f.write(submission.source)
+      f.close
+    end
+    
+    def clean_up(test_request)
+      problem_home = problem_home_dir(test_request)
+      remove_data_files(problem_home)
+    end
+    
+    protected
+    def grading_room_dir(test_request)
+      problem_name = test_request.problem_name
+      user = test_request.user
+      "#{@config.user_result_dir}" + 
+        "/#{user.login}/test_request" +
+        "/#{problem_name}/#{test_request.id}"
+    end
+    
+    def problem_home_dir(test_request)
+      problem_name = test_request.problem_name
+      user = test_request.user
+      "#{@config.user_result_dir}" + 
+        "/#{user.login}/test_request/#{problem_name}"
+    end
+    
+    def copy_problem_template(template_dir,problem_home)
+      cmd = "cp -R #{template_dir}/* #{problem_home}"
+      system_and_raise_when_fail(cmd,"Test Request: cannot copy problem template")
+    end
+    
+    def link_input_file(test_request,problem_home)
+      cmd = "ln -s #{test_request.input_file_name} #{problem_home}/test_cases/1/input-1.txt"
+      system_and_raise_when_fail(cmd,"Test Request: cannot link input file")
+    end
+    
+    def remove_data_files(problem_home)
+      if File.exists?("#{problem_home}/test_cases/1/input-1.txt")
+        cmd = "rm #{problem_home}/test_cases/1/*"
+        system_and_raise_when_fail(cmd,"Test Request: cannot remove data files")
+      end
+    end
+    
+    def system_and_raise_when_fail(cmd,msg)
+      if !system(cmd)
+        raise msg
+      end
+    end
+    
+  end
+  
+  class TestRequestReporter
+    def initialize
+      @config = Grader::Configuration.get_instance
+    end
+    
+    def report(test_request,test_result_dir)
+      save_result(test_request,read_result(test_result_dir))
+    end
+
+    def report_error(test_request, msg)
+      save_result(test_request, {:running_stat => "#{msg}"})
+    end
+    
+    protected
+    def read_result(test_result_dir)
+      # TODO:
+      cmp_msg_fname = "#{test_result_dir}/compiler_message"
+      cmp_file = File.open(cmp_msg_fname)
+      cmp_msg = cmp_file.read
+      cmp_file.close
+      
+      result_file_name = "#{test_result_dir}/1/result"
+
+      if File.exists?(result_file_name)
+        output_file_name = "#{test_result_dir}/1/output.txt"
+        results = File.open("#{test_result_dir}/1/result").readlines
+        stat = format_running_stat(results)
+
+        return {
+          :output_file_name => output_file_name,
+          :running_stat => stat,
+          :comment => "", 
+          :cmp_msg => cmp_msg}
+      else
+        return {
+          :running_stat => "",
+          :comment => "Compilation error", 
+          :cmp_msg => cmp_msg}
+      end
+    end
+
+    def format_running_stat(results)
+      running_time_line = results[-1]
+
+      run_stat = ""
+      if !(/[Cc]orrect/.match(results[0]))
+        run_stat = results[0].chomp
+      end
+
+      if res = /r(.*)u(.*)s/.match(running_time_line)
+        seconds = (res[1].to_f + res[2].to_f)
+        time_stat = "Time used: #{seconds} sec."
+      else
+        time_stat = "Time used: n/a sec."
+      end
+      return "#{run_stat}#{time_stat}"
+    end
+    
+    def save_result(test_request,result)
+      if result[:output_file_name]!=nil
+        test_request.output_file_name = link_output_file(test_request,
+                                                         result[:output_file_name])
+      end
+      test_request.graded_at = Time.now
+      test_request.compiler_message = (result[:cmp_msg] or '')
+      test_request.grader_comment = (result[:comment] or '')
+      test_request.running_stat = (result[:running_stat] or '')
+      test_request.save
+    end
+    
+    protected
+    def link_output_file(test_request, fname)
+      target_file_name = random_output_file_name(test_request.user,
+                                                 test_request.problem)
+      FileUtils.mkdir_p(File.dirname(target_file_name))
+      cmd = "ln -s #{fname} #{target_file_name}"
+      if !system(cmd)
+        raise "TestRequestReporter: cannot move output file"
+      end
+      return target_file_name
+    end
+
+    def random_output_file_name(user,problem)
+      problem_name = TestRequest.name_of(problem)
+      begin
+        tmpname =  "#{@config.test_request_output_base_dir}" +
+          "/#{user.login}/#{problem_name}/#{rand(10000)}"
+      end while File.exists?(tmpname)
+      tmpname
+    end
+
+  end
+  
+end
diff --git a/std-script/grade b/std-script/grade
--- a/std-script/grade
+++ b/std-script/grade
@@ -20,7 +20,7 @@
   elsif comment =~ /[Tt]ime/
     'T'
   else
-    '?'
+    'x'  # these are run time errors
   end
 end
 
diff --git a/std-script/run b/std-script/run
--- a/std-script/run
+++ b/std-script/run
@@ -12,6 +12,18 @@
   end
 end
 
+def extract_time(t)
+  if (result=/^(.*)r(.*)u(.*)s/.match(t))
+    {:real => result[1], :user => result[2], :sys => result[3]}
+  else
+    raise "Error reading running time"
+  end
+end
+
+def compile_box(source,bin)
+  system("gcc #{source} -o #{bin}")
+end
+
 if ARGV.length < 2 || ARGV.length > 3
   puts "Usage: run <language> <test-num> [<program-name>]"
   exit(127)
@@ -55,8 +67,17 @@
 # Copy the input file.
 #`cp #{problem_home}/test_cases/#{test_num}/#{input_file_name} .`
 
+time_output_format = "%Er%Uu%Ss"
+
+# check if box is there, if not, compile it!
+if !File.exists?("#{problem_home}/script/box")
+  log "WARNING: Compiling box: to increase efficiency, it should be compile manually"
+  compile_box("#{problem_home}/script/box.c",
+              "#{problem_home}/script/box")
+end
+
 # Run the program.
-run_command = "/usr/bin/time -f \"%E\" 2>run_result #{problem_home}/script/box -a 2 -f -t #{time_limit} -m #{mem_limit} -i #{input_file_name} -o output.txt #{program_name}"
+run_command = "/usr/bin/time -f \"#{time_output_format}\" 2>run_result #{problem_home}/script/box -a 2 -f -t #{time_limit} -m #{mem_limit} -i #{input_file_name} -o output.txt #{program_name}"
 log "Running test #{test_num}..."
 log run_command
 log 
@@ -71,6 +92,7 @@
 run_result = run_result_file.readlines
 run_result_file.close
 time_elapsed = run_result[run_result.length-1]
+running_time = extract_time(time_elapsed)
 
 report = lambda{ |status, points, comment|
   result_file.write status.strip
@@ -99,6 +121,11 @@
   report.call(run_result[0], 0, "No comment.\n")
 end
 
+if running_time[:user].to_f + running_time[:sys].to_f > time_limit
+  log "Time limit exceeded."
+  report.call("Time limit exceeded", 0, "No comment.\n")
+end
+
 # Run 'check' to evaluate the output.
 #puts "There was no runtime error. Proceed to checking the output."
 check_command = "#{problem_home}/script/check #{language} #{test_num}"
diff --git a/templates/all_tests.cfg.erb b/templates/all_tests.cfg.erb
new file mode 100755
--- /dev/null
+++ b/templates/all_tests.cfg.erb
@@ -0,0 +1,13 @@
+problem do
+  num_tests <%= num_testcases %>
+  full_score <%= num_testcases*10 %>
+  time_limit_each <%= options[:time_limit] %>
+  mem_limit_each <%= options[:mem_limit] %>
+  score_each 10
+
+<% 1.upto(num_testcases) do |i| %>
+  run <%= i %> do
+    tests <%= i %>
+  end
+<% end %>
+end
diff --git a/templates/answer-1.txt b/templates/answer-1.txt
new file mode 100644
diff --git a/templates/check_empty b/templates/check_empty
new file mode 100755
--- /dev/null
+++ b/templates/check_empty
@@ -0,0 +1,47 @@
+#!/usr/bin/ruby
+
+problem_home = ENV['PROBLEM_HOME']
+require "#{problem_home}/script/test_dsl.rb"
+
+if ARGV.length < 2
+  puts "Usage: check <language> <test-number> [<output-file>]"
+  exit(0)
+end
+
+language = ARGV[0]
+test_num = ARGV[1].to_i
+if ARGV.length >= 3
+  output_file_name = ARGV[2]
+else
+  output_file_name = "output.txt"
+end
+
+load "#{problem_home}/test_cases/all_tests.cfg"
+problem = Problem.get_instance
+
+output_file = File.new(output_file_name, "r")
+answer_file = File.new("#{problem_home}/test_cases/#{test_num}/answer-#{test_num}.txt")
+result_file = File.new("check_result", "w")
+
+output_file_content = output_file.read
+answer_file_content = answer_file.read
+
+report_correct = lambda {
+  result_file.write "Correct\n"
+  result_file.write problem.get_score(test_num)
+  result_file.write "\n"  
+  result_file.close
+  exit(0)
+}
+
+report_wrong = lambda {
+  result_file.write "Incorrect\n"
+  result_file.write "0\n"
+  result_file.close
+  exit(0)
+}
+
+##################
+# Your code here #
+##################
+report_correct.call
diff --git a/templates/test_request_all_tests.cfg.erb b/templates/test_request_all_tests.cfg.erb
new file mode 100755
--- /dev/null
+++ b/templates/test_request_all_tests.cfg.erb
@@ -0,0 +1,12 @@
+problem do
+  num_tests 1
+  full_score 10
+  time_limit_each <%= options[:time_limit] %>
+  mem_limit_each <%= options[:mem_limit] %>
+  score_each 10
+
+  run 1 do
+    tests 1
+  end
+
+end
diff --git a/test/data/add_nonzero_exit_status.c b/test/data/add_nonzero_exit_status.c
new file mode 100644
--- /dev/null
+++ b/test/data/add_nonzero_exit_status.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main()
+{
+  int a,b;
+  scanf("%d %d",&a,&b);
+  printf("%d\n",a+b);
+  return 10;
+}
+
diff --git a/test/data/add_too_much_memory_dynamic.c b/test/data/add_too_much_memory_dynamic.c
new file mode 100644
--- /dev/null
+++ b/test/data/add_too_much_memory_dynamic.c
@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main()
+{
+  int a,b;
+  char *huge_array;
+
+  scanf("%d %d",&a,&b);
+
+  huge_array = (char *)malloc(5000000);
+  if(huge_array==NULL)
+    printf("NO!");
+  else
+    printf("%d\n",a+b);
+
+  return 0;
+}
+
diff --git a/test/data/add_too_much_memory_static.c b/test/data/add_too_much_memory_static.c
new file mode 100644
--- /dev/null
+++ b/test/data/add_too_much_memory_static.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+int big_array[2000000];
+
+int main()
+{
+  int a,b;
+  scanf("%d %d",&a,&b);
+  printf("%d\n",a+b);
+  return 0;
+}
+
diff --git a/test/data/ev/test1/script/check b/test/data/ev/test1/script/check
deleted file mode 100755
--- a/test/data/ev/test1/script/check
+++ /dev/null
@@ -1,59 +0,0 @@
-#!/usr/bin/ruby
-
-problem_home = ENV['PROBLEM_HOME']
-require "#{problem_home}/script/test_dsl.rb"
-
-if ARGV.length < 2
-  puts "Usage: check <language> <test-number> [<output-file>]"
-  exit(0)
-end
-
-language = ARGV[0]
-test_num = ARGV[1].to_i
-if ARGV.length >= 3
-  output_file_name = ARGV[2]
-else
-  output_file_name = "output.txt"
-end
-
-load "#{problem_home}/test_cases/all_tests.cfg"
-problem = Problem.get_instance
-
-output_file = File.new(output_file_name, "r")
-answer_file = File.new("#{problem_home}/test_cases/#{test_num}/answer-#{test_num}.txt")
-result_file = File.new("check_result", "w")
-
-output_file_content = output_file.read
-answer_file_content = answer_file.read
-
-report_correct = lambda {
-  result_file.write "Correct\n"
-  result_file.write problem.get_score(test_num)
-  result_file.write "\n"  
-  result_file.close
-  exit(0)
-}
-
-report_wrong = lambda {
-  result_file.write "Incorrect\n"
-  result_file.write "0\n"
-  result_file.close
-  exit(0)
-}
-
-##################
-# Your code here #
-##################
-num_pattern = /^[0-9]*/
-if (output_file_content =~ num_pattern) == nil
-  report_wrong.call
-end
-
-output_i = output_file_content.to_i
-answer_i = answer_file_content.to_i
-
-if output_i == answer_i
-  report_correct.call
-else 
-  report_wrong.call
-end
diff --git a/test/data/ev/test1/test_cases/1/answer-1.txt b/test/data/ev/test1/test_cases/1/answer-1.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/1/answer-1.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-2
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/1/input-1.txt b/test/data/ev/test1/test_cases/1/input-1.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/1/input-1.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-1 1
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/10/answer-10.txt b/test/data/ev/test1/test_cases/10/answer-10.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/10/answer-10.txt
+++ /dev/null
@@ -1,1 +0,0 @@
--256
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/10/input-10.txt b/test/data/ev/test1/test_cases/10/input-10.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/10/input-10.txt
+++ /dev/null
@@ -1,1 +0,0 @@
--128 -128
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/2/answer-2.txt b/test/data/ev/test1/test_cases/2/answer-2.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/2/answer-2.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-32
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/2/input-2.txt b/test/data/ev/test1/test_cases/2/input-2.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/2/input-2.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-20 12
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/3/answer-3.txt b/test/data/ev/test1/test_cases/3/answer-3.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/3/answer-3.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-4
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/3/input-3.txt b/test/data/ev/test1/test_cases/3/input-3.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/3/input-3.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-1 3
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/3/test.cfg b/test/data/ev/test1/test_cases/3/test.cfg
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/3/test.cfg
+++ /dev/null
@@ -1,1 +0,0 @@
-mem_limit 32
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/4/answer-4.txt b/test/data/ev/test1/test_cases/4/answer-4.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/4/answer-4.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-64
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/4/input-4.txt b/test/data/ev/test1/test_cases/4/input-4.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/4/input-4.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-32 32
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/5/answer-5.txt b/test/data/ev/test1/test_cases/5/answer-5.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/5/answer-5.txt
+++ /dev/null
@@ -1,1 +0,0 @@
--2
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/5/input-5.txt b/test/data/ev/test1/test_cases/5/input-5.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/5/input-5.txt
+++ /dev/null
@@ -1,1 +0,0 @@
--1 -1
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/6/answer-6.txt b/test/data/ev/test1/test_cases/6/answer-6.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/6/answer-6.txt
+++ /dev/null
@@ -1,1 +0,0 @@
--32
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/6/input-6.txt b/test/data/ev/test1/test_cases/6/input-6.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/6/input-6.txt
+++ /dev/null
@@ -1,1 +0,0 @@
--16 -16
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/7/answer-7.txt b/test/data/ev/test1/test_cases/7/answer-7.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/7/answer-7.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-0
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/7/input-7.txt b/test/data/ev/test1/test_cases/7/input-7.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/7/input-7.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-0 0
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/8/answer-8.txt b/test/data/ev/test1/test_cases/8/answer-8.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/8/answer-8.txt
+++ /dev/null
@@ -1,1 +0,0 @@
--1
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/8/input-8.txt b/test/data/ev/test1/test_cases/8/input-8.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/8/input-8.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-0 -1
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/8/test.cfg b/test/data/ev/test1/test_cases/8/test.cfg
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/8/test.cfg
+++ /dev/null
@@ -1,1 +0,0 @@
-mem_limit 64
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/9/answer-9.txt b/test/data/ev/test1/test_cases/9/answer-9.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/9/answer-9.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-256
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/9/input-9.txt b/test/data/ev/test1/test_cases/9/input-9.txt
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/9/input-9.txt
+++ /dev/null
@@ -1,1 +0,0 @@
-128 128
\ No newline at end of file
diff --git a/test/data/ev/test1/test_cases/all_tests.cfg b/test/data/ev/test1/test_cases/all_tests.cfg
deleted file mode 100644
--- a/test/data/ev/test1/test_cases/all_tests.cfg
+++ /dev/null
@@ -1,39 +0,0 @@
-problem do
-  num_tests 10
-  full_score 135
-  time_limit_each 1
-  mem_limit_each 11
-  score_each 10
-
-  run 1 do
-    tests 1, 2
-    scores 10, 20
-    time_limits 1, 2
-    mem_limits 5, 6
-  end
-
-  run 2 do
-    tests 3, 4, 5, 6, 7
-    score_each 10
-    time_limit_each 3                  
-    mem_limit_each 3 
-  end
-
-  run 3 do     
-    tests 8, 9, 10
-  end
-
-  test 8 do
-    score 30
-    time_limit 3
-    mem_limit 10
-  end
- 
-  test 9 do
-    score 15
-  end
-
-  test 10 do
-    time_limit 1
-  end
-end
diff --git a/test/data/ev/test2/script/check b/test/data/ev/test2/script/check
deleted file mode 100755
--- a/test/data/ev/test2/script/check
+++ /dev/null
@@ -1,59 +0,0 @@
-#!/usr/bin/ruby
-
-problem_home = ENV['PROBLEM_HOME']
-require "#{problem_home}/script/test_dsl.rb"
-
-if ARGV.length < 2
-  puts "Usage: check <language> <test-number> [<output-file>]"
-  exit(0)
-end
-
-language = ARGV[0]
-test_num = ARGV[1].to_i
-if ARGV.length >= 3
-  output_file_name = ARGV[2]
-else
-  output_file_name = "output.txt"
-end
-
-load "#{problem_home}/test_cases/all_tests.cfg"
-problem = Problem.get_instance
-
-output_file = File.new(output_file_name, "r")
-answer_file = File.new("#{problem_home}/test_cases/#{test_num}/answer-#{test_num}.txt")
-result_file = File.new("check_result", "w")
-
-output_file_content = output_file.read
-answer_file_content = answer_file.read
-
-report_correct = lambda {
-  result_file.write "Correct\n"
-  result_file.write problem.get_score(test_num)
-  result_file.write "\n"  
-  result_file.close
-  exit(0)
-}
-
-report_wrong = lambda {
-  result_file.write "Incorrect\n"
-  result_file.write "0\n"
-  result_file.close
-  exit(0)
-}
-
-##################
-# Your code here #
-##################
-num_pattern = /^[0-9]*/
-if (output_file_content =~ num_pattern) == nil
-  report_wrong.call
-end
-
-output_i = output_file_content.to_i
-answer_i = answer_file_content.to_i
-
-if output_i == answer_i
-  report_correct.call
-else 
-  report_wrong.call
-end
diff --git a/test/data/ev/test2/test_cases/1/answer-1.txt b/test/data/ev/test2/test_cases/1/answer-1.txt
deleted file mode 100644
--- a/test/data/ev/test2/test_cases/1/answer-1.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-2
-
diff --git a/test/data/ev/test2/test_cases/1/input-1.txt b/test/data/ev/test2/test_cases/1/input-1.txt
deleted file mode 100644
--- a/test/data/ev/test2/test_cases/1/input-1.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-1 1
-
diff --git a/test/data/ev/test2/test_cases/2/answer-2.txt b/test/data/ev/test2/test_cases/2/answer-2.txt
deleted file mode 100644
--- a/test/data/ev/test2/test_cases/2/answer-2.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-2
-
diff --git a/test/data/ev/test2/test_cases/2/input-2.txt b/test/data/ev/test2/test_cases/2/input-2.txt
deleted file mode 100644
--- a/test/data/ev/test2/test_cases/2/input-2.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-1 1
-
diff --git a/test/data/ev/test2/test_cases/all_tests.cfg b/test/data/ev/test2/test_cases/all_tests.cfg
deleted file mode 100644
--- a/test/data/ev/test2/test_cases/all_tests.cfg
+++ /dev/null
@@ -1,20 +0,0 @@
-problem do
-  num_tests 2
-  full_score 10
-  time_limit_each 1
-  mem_limit_each 16
-  score_each 10
-
-  run 1 do
-    tests 1
-  end
-
-  test 2 do
-    time_limit 2
-  end
-
-  run 2 do
-    tests 2
-  end
-    
-end
diff --git a/test/data/ev/test_memory/script/check b/test/data/ev/test_memory/script/check
new file mode 100755
--- /dev/null
+++ b/test/data/ev/test_memory/script/check
@@ -0,0 +1,59 @@
+#!/usr/bin/ruby
+
+problem_home = ENV['PROBLEM_HOME']
+require "#{problem_home}/script/test_dsl.rb"
+
+if ARGV.length < 2
+  puts "Usage: check <language> <test-number> [<output-file>]"
+  exit(0)
+end
+
+language = ARGV[0]
+test_num = ARGV[1].to_i
+if ARGV.length >= 3
+  output_file_name = ARGV[2]
+else
+  output_file_name = "output.txt"
+end
+
+load "#{problem_home}/test_cases/all_tests.cfg"
+problem = Problem.get_instance
+
+output_file = File.new(output_file_name, "r")
+answer_file = File.new("#{problem_home}/test_cases/#{test_num}/answer-#{test_num}.txt")
+result_file = File.new("check_result", "w")
+
+output_file_content = output_file.read
+answer_file_content = answer_file.read
+
+report_correct = lambda {
+  result_file.write "Correct\n"
+  result_file.write problem.get_score(test_num)
+  result_file.write "\n"  
+  result_file.close
+  exit(0)
+}
+
+report_wrong = lambda {
+  result_file.write "Incorrect\n"
+  result_file.write "0\n"
+  result_file.close
+  exit(0)
+}
+
+##################
+# Your code here #
+##################
+num_pattern = /^[0-9]*/
+if (output_file_content =~ num_pattern) == nil
+  report_wrong.call
+end
+
+output_i = output_file_content.to_i
+answer_i = answer_file_content.to_i
+
+if output_i == answer_i
+  report_correct.call
+else 
+  report_wrong.call
+end
diff --git a/test/data/ev/test_memory/test_cases/1/answer-1.txt b/test/data/ev/test_memory/test_cases/1/answer-1.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_memory/test_cases/1/answer-1.txt
@@ -0,0 +1,2 @@
+2
+
diff --git a/test/data/ev/test_memory/test_cases/1/input-1.txt b/test/data/ev/test_memory/test_cases/1/input-1.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_memory/test_cases/1/input-1.txt
@@ -0,0 +1,2 @@
+1 1
+
diff --git a/test/data/ev/test_memory/test_cases/2/answer-2.txt b/test/data/ev/test_memory/test_cases/2/answer-2.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_memory/test_cases/2/answer-2.txt
@@ -0,0 +1,2 @@
+2
+
diff --git a/test/data/ev/test_memory/test_cases/2/input-2.txt b/test/data/ev/test_memory/test_cases/2/input-2.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_memory/test_cases/2/input-2.txt
@@ -0,0 +1,2 @@
+1 1
+
diff --git a/test/data/ev/test_memory/test_cases/all_tests.cfg b/test/data/ev/test_memory/test_cases/all_tests.cfg
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_memory/test_cases/all_tests.cfg
@@ -0,0 +1,20 @@
+problem do
+  num_tests 2
+  full_score 20
+  time_limit_each 1
+  mem_limit_each 5
+  score_each 10
+
+  run 1 do
+    tests 1
+  end
+
+  test 2 do
+    mem_limit 10
+  end
+
+  run 2 do
+    tests 2
+  end
+    
+end
diff --git a/test/data/ev/test_normal/script/check b/test/data/ev/test_normal/script/check
new file mode 100755
--- /dev/null
+++ b/test/data/ev/test_normal/script/check
@@ -0,0 +1,59 @@
+#!/usr/bin/ruby
+
+problem_home = ENV['PROBLEM_HOME']
+require "#{problem_home}/script/test_dsl.rb"
+
+if ARGV.length < 2
+  puts "Usage: check <language> <test-number> [<output-file>]"
+  exit(0)
+end
+
+language = ARGV[0]
+test_num = ARGV[1].to_i
+if ARGV.length >= 3
+  output_file_name = ARGV[2]
+else
+  output_file_name = "output.txt"
+end
+
+load "#{problem_home}/test_cases/all_tests.cfg"
+problem = Problem.get_instance
+
+output_file = File.new(output_file_name, "r")
+answer_file = File.new("#{problem_home}/test_cases/#{test_num}/answer-#{test_num}.txt")
+result_file = File.new("check_result", "w")
+
+output_file_content = output_file.read
+answer_file_content = answer_file.read
+
+report_correct = lambda {
+  result_file.write "Correct\n"
+  result_file.write problem.get_score(test_num)
+  result_file.write "\n"  
+  result_file.close
+  exit(0)
+}
+
+report_wrong = lambda {
+  result_file.write "Incorrect\n"
+  result_file.write "0\n"
+  result_file.close
+  exit(0)
+}
+
+##################
+# Your code here #
+##################
+num_pattern = /^[0-9]*/
+if (output_file_content =~ num_pattern) == nil
+  report_wrong.call
+end
+
+output_i = output_file_content.to_i
+answer_i = answer_file_content.to_i
+
+if output_i == answer_i
+  report_correct.call
+else 
+  report_wrong.call
+end
diff --git a/test/data/ev/test_normal/test_cases/1/answer-1.txt b/test/data/ev/test_normal/test_cases/1/answer-1.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/1/answer-1.txt
@@ -0,0 +1,1 @@
+2
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/1/input-1.txt b/test/data/ev/test_normal/test_cases/1/input-1.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/1/input-1.txt
@@ -0,0 +1,1 @@
+1 1
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/10/answer-10.txt b/test/data/ev/test_normal/test_cases/10/answer-10.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/10/answer-10.txt
@@ -0,0 +1,1 @@
+-256
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/10/input-10.txt b/test/data/ev/test_normal/test_cases/10/input-10.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/10/input-10.txt
@@ -0,0 +1,1 @@
+-128 -128
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/2/answer-2.txt b/test/data/ev/test_normal/test_cases/2/answer-2.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/2/answer-2.txt
@@ -0,0 +1,1 @@
+32
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/2/input-2.txt b/test/data/ev/test_normal/test_cases/2/input-2.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/2/input-2.txt
@@ -0,0 +1,1 @@
+20 12
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/3/answer-3.txt b/test/data/ev/test_normal/test_cases/3/answer-3.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/3/answer-3.txt
@@ -0,0 +1,1 @@
+4
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/3/input-3.txt b/test/data/ev/test_normal/test_cases/3/input-3.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/3/input-3.txt
@@ -0,0 +1,1 @@
+1 3
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/3/test.cfg b/test/data/ev/test_normal/test_cases/3/test.cfg
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/3/test.cfg
@@ -0,0 +1,1 @@
+mem_limit 32
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/4/answer-4.txt b/test/data/ev/test_normal/test_cases/4/answer-4.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/4/answer-4.txt
@@ -0,0 +1,1 @@
+64
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/4/input-4.txt b/test/data/ev/test_normal/test_cases/4/input-4.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/4/input-4.txt
@@ -0,0 +1,1 @@
+32 32
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/5/answer-5.txt b/test/data/ev/test_normal/test_cases/5/answer-5.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/5/answer-5.txt
@@ -0,0 +1,1 @@
+-2
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/5/input-5.txt b/test/data/ev/test_normal/test_cases/5/input-5.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/5/input-5.txt
@@ -0,0 +1,1 @@
+-1 -1
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/6/answer-6.txt b/test/data/ev/test_normal/test_cases/6/answer-6.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/6/answer-6.txt
@@ -0,0 +1,1 @@
+-32
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/6/input-6.txt b/test/data/ev/test_normal/test_cases/6/input-6.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/6/input-6.txt
@@ -0,0 +1,1 @@
+-16 -16
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/7/answer-7.txt b/test/data/ev/test_normal/test_cases/7/answer-7.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/7/answer-7.txt
@@ -0,0 +1,1 @@
+0
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/7/input-7.txt b/test/data/ev/test_normal/test_cases/7/input-7.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/7/input-7.txt
@@ -0,0 +1,1 @@
+0 0
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/8/answer-8.txt b/test/data/ev/test_normal/test_cases/8/answer-8.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/8/answer-8.txt
@@ -0,0 +1,1 @@
+-1
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/8/input-8.txt b/test/data/ev/test_normal/test_cases/8/input-8.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/8/input-8.txt
@@ -0,0 +1,1 @@
+0 -1
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/8/test.cfg b/test/data/ev/test_normal/test_cases/8/test.cfg
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/8/test.cfg
@@ -0,0 +1,1 @@
+mem_limit 64
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/9/answer-9.txt b/test/data/ev/test_normal/test_cases/9/answer-9.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/9/answer-9.txt
@@ -0,0 +1,1 @@
+256
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/9/input-9.txt b/test/data/ev/test_normal/test_cases/9/input-9.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/9/input-9.txt
@@ -0,0 +1,1 @@
+128 128
\ No newline at end of file
diff --git a/test/data/ev/test_normal/test_cases/all_tests.cfg b/test/data/ev/test_normal/test_cases/all_tests.cfg
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_normal/test_cases/all_tests.cfg
@@ -0,0 +1,39 @@
+problem do
+  num_tests 10
+  full_score 135
+  time_limit_each 1
+  mem_limit_each 11
+  score_each 10
+
+  run 1 do
+    tests 1, 2
+    scores 10, 20
+    time_limits 1, 2
+    mem_limits 5, 6
+  end
+
+  run 2 do
+    tests 3, 4, 5, 6, 7
+    score_each 10
+    time_limit_each 3                  
+    mem_limit_each 3 
+  end
+
+  run 3 do     
+    tests 8, 9, 10
+  end
+
+  test 8 do
+    score 30
+    time_limit 3
+    mem_limit 10
+  end
+ 
+  test 9 do
+    score 15
+  end
+
+  test 10 do
+    time_limit 1
+  end
+end
diff --git a/test/data/ev/test_timeout/script/check b/test/data/ev/test_timeout/script/check
new file mode 100755
--- /dev/null
+++ b/test/data/ev/test_timeout/script/check
@@ -0,0 +1,59 @@
+#!/usr/bin/ruby
+
+problem_home = ENV['PROBLEM_HOME']
+require "#{problem_home}/script/test_dsl.rb"
+
+if ARGV.length < 2
+  puts "Usage: check <language> <test-number> [<output-file>]"
+  exit(0)
+end
+
+language = ARGV[0]
+test_num = ARGV[1].to_i
+if ARGV.length >= 3
+  output_file_name = ARGV[2]
+else
+  output_file_name = "output.txt"
+end
+
+load "#{problem_home}/test_cases/all_tests.cfg"
+problem = Problem.get_instance
+
+output_file = File.new(output_file_name, "r")
+answer_file = File.new("#{problem_home}/test_cases/#{test_num}/answer-#{test_num}.txt")
+result_file = File.new("check_result", "w")
+
+output_file_content = output_file.read
+answer_file_content = answer_file.read
+
+report_correct = lambda {
+  result_file.write "Correct\n"
+  result_file.write problem.get_score(test_num)
+  result_file.write "\n"  
+  result_file.close
+  exit(0)
+}
+
+report_wrong = lambda {
+  result_file.write "Incorrect\n"
+  result_file.write "0\n"
+  result_file.close
+  exit(0)
+}
+
+##################
+# Your code here #
+##################
+num_pattern = /^[0-9]*/
+if (output_file_content =~ num_pattern) == nil
+  report_wrong.call
+end
+
+output_i = output_file_content.to_i
+answer_i = answer_file_content.to_i
+
+if output_i == answer_i
+  report_correct.call
+else 
+  report_wrong.call
+end
diff --git a/test/data/ev/test_timeout/test_cases/1/answer-1.txt b/test/data/ev/test_timeout/test_cases/1/answer-1.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_timeout/test_cases/1/answer-1.txt
@@ -0,0 +1,2 @@
+2
+
diff --git a/test/data/ev/test_timeout/test_cases/1/input-1.txt b/test/data/ev/test_timeout/test_cases/1/input-1.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_timeout/test_cases/1/input-1.txt
@@ -0,0 +1,2 @@
+1 1
+
diff --git a/test/data/ev/test_timeout/test_cases/2/answer-2.txt b/test/data/ev/test_timeout/test_cases/2/answer-2.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_timeout/test_cases/2/answer-2.txt
@@ -0,0 +1,2 @@
+2
+
diff --git a/test/data/ev/test_timeout/test_cases/2/input-2.txt b/test/data/ev/test_timeout/test_cases/2/input-2.txt
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_timeout/test_cases/2/input-2.txt
@@ -0,0 +1,2 @@
+1 1
+
diff --git a/test/data/ev/test_timeout/test_cases/all_tests.cfg b/test/data/ev/test_timeout/test_cases/all_tests.cfg
new file mode 100644
--- /dev/null
+++ b/test/data/ev/test_timeout/test_cases/all_tests.cfg
@@ -0,0 +1,20 @@
+problem do
+  num_tests 2
+  full_score 20
+  time_limit_each 1
+  mem_limit_each 16
+  score_each 10
+
+  run 1 do
+    tests 1
+  end
+
+  test 2 do
+    time_limit 2
+  end
+
+  run 2 do
+    tests 2
+  end
+    
+end
diff --git a/test/data/test2_1-5sec.c b/test/data/test2_1-5sec.c
--- a/test/data/test2_1-5sec.c
+++ b/test/data/test2_1-5sec.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 
 int main()
 {
@@ -15,5 +16,6 @@
       b+=c;
     }
   }
+  exit(0);
 }
 
diff --git a/test/data/test_request/input/in1.txt b/test/data/test_request/input/in1.txt
new file mode 100644
--- /dev/null
+++ b/test/data/test_request/input/in1.txt
@@ -0,0 +1,2 @@
+10
+20
diff --git a/test/data/test_request/problems/test_normal/script/check b/test/data/test_request/problems/test_normal/script/check
new file mode 100755
--- /dev/null
+++ b/test/data/test_request/problems/test_normal/script/check
@@ -0,0 +1,47 @@
+#!/usr/bin/ruby
+
+problem_home = ENV['PROBLEM_HOME']
+require "#{problem_home}/script/test_dsl.rb"
+
+if ARGV.length < 2
+  puts "Usage: check <language> <test-number> [<output-file>]"
+  exit(0)
+end
+
+language = ARGV[0]
+test_num = ARGV[1].to_i
+if ARGV.length >= 3
+  output_file_name = ARGV[2]
+else
+  output_file_name = "output.txt"
+end
+
+load "#{problem_home}/test_cases/all_tests.cfg"
+problem = Problem.get_instance
+
+output_file = File.new(output_file_name, "r")
+answer_file = File.new("#{problem_home}/test_cases/#{test_num}/answer-#{test_num}.txt")
+result_file = File.new("check_result", "w")
+
+output_file_content = output_file.read
+answer_file_content = answer_file.read
+
+report_correct = lambda {
+  result_file.write "Correct\n"
+  result_file.write problem.get_score(test_num)
+  result_file.write "\n"  
+  result_file.close
+  exit(0)
+}
+
+report_wrong = lambda {
+  result_file.write "Incorrect\n"
+  result_file.write "0\n"
+  result_file.close
+  exit(0)
+}
+
+##################
+# Your code here #
+##################
+report_correct.call
diff --git a/test/data/test_request/problems/test_normal/test_cases/1/answer-1.txt b/test/data/test_request/problems/test_normal/test_cases/1/answer-1.txt
new file mode 100644
diff --git a/test/data/test_request/problems/test_normal/test_cases/all_tests.cfg b/test/data/test_request/problems/test_normal/test_cases/all_tests.cfg
new file mode 100644
--- /dev/null
+++ b/test/data/test_request/problems/test_normal/test_cases/all_tests.cfg
@@ -0,0 +1,11 @@
+problem do
+  num_tests 1
+  full_score 10
+  time_limit_each 1
+  mem_limit_each 16
+  score_each 10
+
+  run 1 do
+    tests 1
+  end
+end
diff --git a/test/engine_spec.rb b/test/engine_spec.rb
new file mode 100644
--- /dev/null
+++ b/test/engine_spec.rb
@@ -0,0 +1,246 @@
+require File.join(File.dirname(__FILE__),'spec_helper')
+require File.join(File.dirname(__FILE__),'engine_spec_helper')
+
+describe "A grader engine, when grading submissions" do
+
+  include GraderEngineHelperMethods
+
+  before(:each) do
+    @config = Grader::Configuration.get_instance
+
+    # this test is from Pong
+    @problem_test_normal = stub(Problem,
+                                :id => 1, :name => 'test_normal', 
+                                :full_score => 135)
+    @user_user1 = stub(User,
+                       :id => 1, :login => 'user1')
+    
+    @engine = Grader::Engine.new    
+    init_sandbox
+  end
+
+  it "should grade normal submission" do
+    grader_should(:grade => "test1_correct.c",
+                  :on => @problem_test_normal,
+                  :and_report => {
+                    :score => 135,
+                    :comment => /^PASSED/})
+  end
+  
+
+  it "should produce error message when submission cannot compile" do
+    grader_should(:grade => "test1_compile_error.c",
+                  :on => @problem_test_normal,
+                  :and_report => {
+                    :score => 0,
+                    :comment => 'FAILED: compile error',
+                    :compiler_message => /[Ee]rror/})
+  end
+
+  it "should produce timeout error when submission runs forever" do
+    @problem_test_timeout = stub(Problem,
+                                 :id => 1, :name => 'test_timeout', 
+                                 :full_score => 10)
+    grader_should(:grade => "test2_timeout.c",
+                  :on => @problem_test_timeout,
+                  :and_report => {
+                    :score => 0,
+                    :comment => 'FAILED: TT'})
+  end
+
+  it "should produce timeout error correctly when submission runs slower than expected in less than a second" do
+    @problem_test_timeout = stub(Problem,
+                                 :id => 1, :name => 'test_timeout', 
+                                 :full_score => 20)
+    grader_should(:grade => "test2_1-5sec.c",
+                  :on => @problem_test_timeout,
+                  :and_report => {
+                    :score => 10,
+                    :comment => 'FAILED: TP'})
+  end
+  
+  it "should produce runtime error when submission uses too much static memory" do
+    @problem_test_memory = stub(Problem,
+                                :id => 1, :name => 'test_memory', 
+                                :full_score => 20)
+    grader_should(:grade => "add_too_much_memory_static.c",
+                  :on => @problem_test_memory,
+                  :and_report => {
+                    :score => 10,
+                    :comment => /FAILED: [^P]P/})
+  end
+
+  it "should not allow submission to allocate too much dynamic memory" do
+    @problem_test_memory = stub(Problem,
+                                :id => 1, :name => 'test_memory', 
+                                :full_score => 20)
+    grader_should(:grade => "add_too_much_memory_dynamic.c",
+                  :on => @problem_test_memory,
+                  :and_report => {
+                    :score => 10,
+                    :comment => /FAILED: [^P]P/})
+  end
+
+  it "should fail submission with non-zero exit status" do
+    violated("has not been implemented")
+  end
+
+  def grader_should(args)
+    @user1 = stub(User,
+                  :id => 1, :login => 'user1')
+    submission = 
+      create_submission_from_file(1, @user1, args[:on], args[:grade])
+    submission.should_receive(:graded_at=)
+
+    expected_score = args[:and_report][:score]
+    expected_comment = args[:and_report][:comment]
+    if args[:and_report][:compiler_message]!=nil
+      expected_compiler_message = args[:and_report][:compiler_message]
+    else
+      expected_compiler_message = ''
+    end
+
+    submission.should_receive(:points=).with(expected_score)
+    submission.should_receive(:grader_comment=).with(expected_comment)
+    submission.should_receive(:compiler_message=).with(expected_compiler_message)
+    submission.should_receive(:save)
+
+    @engine.grade(submission)
+  end
+
+  protected
+
+  def create_normal_submission_mock_from_file(source_fname)
+    create_submission_from_file(1, @user_user1, @problem_test_normal, source_fname)
+  end
+  
+end
+
+describe "A grader engine, when grading test requests" do
+
+  include GraderEngineHelperMethods
+
+  before(:each) do
+    @config = Grader::Configuration.get_instance
+    @engine = Grader::Engine.new(Grader::TestRequestRoomMaker.new,
+                                 Grader::TestRequestReporter.new)
+    init_sandbox
+  end
+
+  it "should report error if there is no problem template" do
+    problem = stub(Problem,
+                   :id => 1, :name => 'nothing')
+    grader_should(:grade => 'test1_correct.c',
+                  :on => problem,
+                  :with => 'in1.txt',
+                  :and_report => {
+                    :graded_at= => nil,
+                    :compiler_message= => '',
+                    :grader_comment= => '',
+                    :running_stat= => /template not found/,
+                    :save => nil})
+  end
+
+  it "should run test request and produce output file" do
+    problem = stub(Problem,
+                   :id => 1, :name => 'test_normal')
+    grader_should(:grade => 'test1_correct.c',
+                  :on => problem,
+                  :with => 'in1.txt',
+                  :and_report => {
+                    :graded_at= => nil,
+                    :compiler_message= => '',
+                    :grader_comment= => '',
+                    :running_stat= => /0.0 sec./, 
+                    :output_file_name= => lambda { |fname|
+                      File.exists?(fname).should be_true
+                    },
+                    :save => nil})
+  end
+
+  it "should clean up problem directory after running test request" do
+    problem = stub(Problem,
+                   :id => 1, :name => 'test_normal')
+    grader_should(:grade => 'test1_correct.c',
+                  :on => problem,
+                  :with => 'in1.txt',
+                  :and_report => {
+                    :graded_at= => nil,
+                    :compiler_message= => '',
+                    :grader_comment= => '',
+                    :running_stat= => nil, 
+                    :output_file_name= => nil,
+                    :save => nil})
+    File.exists?(@config.user_result_dir + "/test_request/test_normal/test_cases/1/input-1.txt").should be_false
+  end
+
+  it "should compile test request with error and report compilation error" do
+    problem = stub(Problem,
+                   :id => 1, :name => 'test_normal')
+    grader_should(:grade => 'test1_compile_error.c',
+                  :on => problem,
+                  :with => 'in1.txt',
+                  :and_report => {
+                    :graded_at= => nil,
+                    :compiler_message= => /.+/,
+                    :grader_comment= => /[Cc]ompil.*error/,
+                    :running_stat= => '', 
+                    :save => nil})
+  end
+
+  it "should report exit status" do
+    problem = stub(Problem,
+                   :id => 1, :name => 'test_normal')
+    grader_should(:grade => 'add_nonzero_exit_status.c',
+                  :on => problem,
+                  :with => 'in1.txt',
+                  :and_report => {
+                    :graded_at= => nil,
+                    :compiler_message= => '',
+                    :grader_comment= => '',
+                    :running_stat= => /[Ee]xit.*status.*10.*0.0 sec./,
+                    :output_file_name= => lambda { |fname|
+                      File.exists?(fname).should be_true
+                    },
+                    :save => nil})
+  end
+
+  protected
+  def grader_should(args)
+    @user1 = stub(User,
+                  :id => 1, :login => 'user1')
+
+    problem = args[:on]
+    input_file = @config.test_request_input_base_dir + "/" + args[:with]
+
+    submission = 
+      create_submission_from_file(1, @user1, args[:on], args[:grade])
+
+    test_request = stub(TestRequest,
+                        :id => 1,
+                        :user => @user1,
+                        :problem => problem,
+                        :submission => submission,
+                        :input_file_name => input_file,
+                        :language => submission.language,
+                        :problem_name => problem.name)
+
+    expectations = args[:and_report]
+
+    expectations.each do |key,val|
+      if val==nil
+        test_request.should_receive(key)
+      elsif val.class == Proc
+        test_request.should_receive(key) { |fname|
+          val.call(fname)
+        }
+      else
+        test_request.should_receive(key).with(val)
+      end
+    end
+
+    @engine.grade(test_request)
+  end
+
+end
+
diff --git a/test/engine_spec_helper.rb b/test/engine_spec_helper.rb
new file mode 100644
--- /dev/null
+++ b/test/engine_spec_helper.rb
@@ -0,0 +1,30 @@
+module GraderEngineHelperMethods
+
+  def clear_sandbox
+    config = Grader::Configuration.get_instance
+    clear_cmd = "rm -rf #{config.test_sandbox_dir}/*"
+    system(clear_cmd)
+  end
+
+  def init_sandbox
+    config = Grader::Configuration.get_instance
+    clear_sandbox
+    Dir.mkdir config.user_result_dir
+    cp_cmd = "cp -R #{config.test_data_dir}/ev #{config.test_sandbox_dir}"
+    system(cp_cmd)
+  end
+
+  def create_submission_from_file(id, user, problem, 
+                                  source_fname, language=nil)
+
+    language = stub(Language, :name => 'c', :ext => 'c') if language==nil
+
+    config = Grader::Configuration.get_instance
+    source = File.open(config.test_data_dir + "/" + source_fname).read
+    stub(Submission,
+         :id => id, :user => user, :problem => problem,
+         :source => source, :language => language)
+  end
+
+end
+
diff --git a/test/engine_test.rb b/test/engine_test.rb
--- a/test/engine_test.rb
+++ b/test/engine_test.rb
@@ -76,14 +76,14 @@
   end
 
   def test_timeout_submission_running_one_and_a_half_second
-    @problem_test2 = stub(:id => 1, :name => 'test2', :full_score => 10)
+    @problem_test2 = stub(:id => 1, :name => 'test2', :full_score => 20)
     @user_user1 = stub(:id => 1, :login => 'user1')
 
     submission = create_submission_from_file(1, @user_user1, @problem_test2,
                                              "test2_1-5sec.c")
 
     submission.expects(:graded_at=)
-    submission.expects(:points=).with(0)
+    submission.expects(:points=).with(10)
     submission.expects(:grader_comment=).with do |value|
       /^FAILED: TP$/.match value
     end
diff --git a/test/runner_spec.rb b/test/runner_spec.rb
new file mode 100644
--- /dev/null
+++ b/test/runner_spec.rb
@@ -0,0 +1,65 @@
+require File.join(File.dirname(__FILE__),'spec_helper')
+require File.join(File.dirname(__FILE__),'engine_spec_helper')
+
+describe "A grader runner, when grade task" do
+
+  include GraderEngineHelperMethods
+
+  before(:each) do
+    @config = Grader::Configuration.get_instance
+    @problem_test_normal = stub(Problem,
+                                :id => 1, :name => 'test_normal', 
+                                :full_score => 135)
+    @user_user1 = stub(User,
+                       :id => 1, :login => 'user1')
+    
+    @engine = Grader::Engine.new    
+    @runner = Grader::Runner.new(@engine)
+    init_sandbox
+  end
+
+  it "should just return nil when there is no submission" do
+    Task.should_receive(:get_inqueue_and_change_status).and_return(nil)
+    @runner.grade_oldest_task.should be_nil
+  end
+
+  it "should grade oldest task in queue" do
+    submission = create_normal_submission_mock_from_file("test1_correct.c")
+
+    submission.should_receive(:graded_at=)
+    submission.should_receive(:points=).with(135)
+    submission.should_receive(:grader_comment=).with(/^PASSED/)
+    submission.should_receive(:compiler_message=).with('')
+    submission.should_receive(:save)
+
+    # mock task
+    task = stub(Task,:id => 1, :submission_id => submission.id)
+    Task.should_receive(:get_inqueue_and_change_status).and_return(task)
+    task.should_receive(:status_complete!)
+
+    # mock Submission
+    Submission.should_receive(:find).
+      with(task.submission_id).
+      and_return(submission)
+
+    @runner.grade_oldest_task
+  end
+
+  # to be converted
+  def test_grade_oldest_task_with_grader_process
+    grader_process = stub
+    grader_process.expects(:report_active)
+
+    @runner = Grader::Runner.new(@engine,grader_process)
+
+    test_grade_oldest_task
+  end
+
+  protected
+
+  def create_normal_submission_mock_from_file(source_fname)
+    create_submission_from_file(1, @user_user1, @problem_test_normal, source_fname)
+  end
+  
+end
+
diff --git a/test/spec_helper.rb b/test/spec_helper.rb
new file mode 100644
--- /dev/null
+++ b/test/spec_helper.rb
@@ -0,0 +1,25 @@
+
+# This test helper loads the grader's environment and rails environment
+
+GRADER_ENV = 'test'
+require File.join(File.dirname(__FILE__),'../config/environment')
+
+
+# this shall be removed soon
+RAILS_ENV = Grader::Configuration.get_instance.rails_env
+require RAILS_ROOT + '/config/environment'
+
+# make sure not to access real database!
+# taken from http://blog.jayfields.com/2006/06/ruby-on-rails-unit-tests.html
+
+class UnitTest
+  def self.TestCase
+    class << ActiveRecord::Base
+      def connection
+        raise 'You cannot access the database from a unit test'
+#        raise InvalidActionError, 'You cannot access the database from a unit test', caller
+      end
+    end
+    Test::Unit::TestCase
+  end
+end