Improvement on lua testing concept.lua

spec = {  
  specs = {}, passed = 0,  failed = 0,  current = nil
}

function spec.report(success, message)
  spec.current.success = success
  if success then
    spec.passed = spec.passed + 1
  else
    spec.failed = spec.failed + 1
    spec.current.message = message
    spec.current.trace =  debug.traceback()
  end
end

--
--  Collection of shoud matchers

matchers = {
  should_be = function(self, expected) 
    local success = self.value == expected
    local message

    if not success then
      message = "\texpecting : " .. tostring(expected) .. ", not ".. self.value
    end
    spec.report(success, message)
  end;
  
  should_be_true = function(self) 
    local success = self.value == true
    local message
    
    if not success then
      message = "\texpecting : true " .. tostring(expected) .. ", not ".. self.value
    end
    spec.report(success, message)
  end;
  
  should_be_false = function(self) end;
  should_be_nil = function(self) end;
  should_not_be = function(self) end;
  should_equal = function(self, expected) end;
  should_match = function(self, pattern) end;
}

--  Expectation function
--
function expect(target)
  local instance = {}
  instance.value = target
  
  local matcher = function(self, method) 
    return function(...)
      if matchers[method] then
        matchers[method](self, ...) 
      end
    end
  end
  setmetatable(instance, {__index = matcher})
  return instance
end

-- Descript a context
-- 
function describe(context) 
  local tests = {}
  
  spec.specs[context] = {}
  
  return function(specs) 
    local instance = {}
    local before = specs.before and specs.before or nil
    local after = specs.after and specs.after or nil
    
    -- prepare
    if before then
      specs.before = nil
      before(instance)      
    end
    if after then
      specs.after = nil
    end

    -- run
    for description, testcase in pairs(specs) do
      spec.specs[context][description] = {}
      spec.current = spec.specs[context][description]
      testcase(instance)
    end

    -- post routine
    if after then
      after(instance)
    end
  end
end


-- Example
----------------------
describe ("array.each") 
{ 

  before = function(self)
    self.list = "{1,2,3}"
  end;
  
  ["should iterate over a collection"] = function(self)
    local result = "abc"
    expect(result).should_be 'abdc'
  end;

  ["should be a function"] = function(self)
    expect(self.list).should_be(self.list)
    
    expect( type(table.foreach) ).should_be 'function'
  end;

  after = function() end
}


-- Very ugly reporting section
-- Ned some refactoring
table.foreach(spec.specs, function(context, cases)
  print (context.."\n============================")
  local index = 1
  table.foreach(cases, function(description, result)
    if result.success then
      print (index .. " - " .. description .. "  :   [ passed ]")
      print ('----------------------------')
    else
      print (index .. " - " .. description .. "  :   [ failed ]")
      print ('----------------------------')
      print (result.message)
      print (result.trace)
    end
    index = index + 1
  end)
end)

print ("Passed : " .. spec.passed ..", Failed : " .. spec.failed .. ". Rate : " ..
      (spec.passed/ (spec.passed + spec.failed))*100 .."%")
print '============================'