middleclass/spec/Object_spec.lua

require 'middleclass'

context('Object', function()


  context('name', function()
    test('is correctly set', function()
      assert_equal(Object.name, 'Object')
    end)
  end)

  context('tostring', function()
    test('returns "class Object"', function()
      assert_equal(tostring(Object), 'class Object')
    end)
  end)

  context('()', function()
    test('returns an object, like Object:new()', function()
      local obj = Object()
      assert_true(instanceOf(Object, obj))
    end)
  end)

  context('subclass', function()

    test('throws an error when used without the :', function()
      assert_error(function() Object.subclass() end)
    end)

    test('throws an error when no name is given', function()
      assert_error( function() Object:subclass() end)
    end)

    context('when given a class name', function()

      local SubClass

      before(function()
        SubClass = Object:subclass('SubClass')
      end)

      test('it returns a class with the correct name', function()
        assert_equal(SubClass.name, 'SubClass')
      end)

      test('it returns a class with the correct superclass', function()
        assert_equal(SubClass.super, Object)
      end)

      test('it includes the subclass in the list of subclasses', function()
        assert_true(Object.subclasses[SubClass])
      end)

    end)

  end)

  context('instance creation', function()

    local SubClass

    before(function()
      SubClass = class('SubClass')
      function SubClass:initialize() self.mark=true end
    end)

   context('allocate', function()

      test('allocates instances properly', function()
        local instance = SubClass:allocate()
        assert_equal(instance.class, SubClass)
        assert_equal(tostring(instance), "instance of " .. tostring(SubClass))
      end)

      test('throws an error when used without the :', function()
        assert_error(Object.allocate)
      end)

      test('does not call the initializer', function()
        local allocated = SubClass:allocate()
        assert_nil(allocated.mark)
      end)

      test('can be overriden', function()

        local previousAllocate = SubClass.static.allocate

        function SubClass.static:allocate()
          local instance = previousAllocate(SubClass)
          instance.mark = true
          return instance
        end

        local allocated = SubClass:allocate()
        assert_true(allocated.mark)

      end)

    end)

    context('new', function()

      test('initializes instances properly', function()
        local instance = SubClass:new()
        assert_equal(instance.class, SubClass)
      end)

      test('throws an error when used without the :', function()
        assert_error(SubClass.new)
      end)

      test('calls the initializer', function()
        local initialized = SubClass:new()
        assert_true(initialized.mark)
      end)

    end)


  end)

end)