 
 
   describe "appending subtraction", ->
-    it_plays_manipulation_role (test)->
-      @manip.build_append_subtraction()
+    it_plays_manipulation_role
+      subject: ->
+        @manip.build_append_subtraction()
 
     it "adds subtraction to the end of the expression", ->
       exp = @exp_builder(1)
-      new_exp = @manip.build_append_subtraction().invoke(exp)
+      new_exp = @manip.build_append_subtraction().perform(exp)
       expect(new_exp.last() instanceof @components.classes.subtraction).toEqual true
 
     it_inserts_component_into_the_last_nested_open_expression(

      should_equal_after: (builder)-> builder(open_expression: {open_expression: ['-']}))

  describe "appending a decimal", ->
    it_plays_manipulation_role ->
      @manip.build_append_decimal(value: 5)

    it "correctly adds a decimal to the value", ->
      exp = @components.build_expression()
      exp = @manip.build_append_number(value: 1).invoke(exp)
      exp = @manip.build_append_decimal().invoke(exp)
      exp = @manip.build_append_number(value: 1).invoke(exp)
      @expect_value(exp, '1.1')

    it_inserts_component_into_the_last_nested_open_expression(



  describe "appending addition", ->
    it_plays_manipulation_role
      subject: ->
        @manip.build_append_addition()

    it "adds addition to the end of the expression", ->
      exp = @exp_builder(1)
      new_exp = @manip.build_append_addition().perform(exp)
      expect(new_exp.last() instanceof @components.classes.addition).toEqual true

    it_inserts_component_into_the_last_nested_open_expression(
