Tests for a simple logo interpreter in Ruby

gistfile1.rb

# clearscreen
# forward INTEGER

# TO funcname
#   do something
# END

# rt INTEGER ; right turn
# lt INTEGER  ; left turn

require "minitest/autorun"

module Logo

  def self.compile(code)

  end

  class ForwardNode 



  end

end

describe "An awesome logo compiler" do
  describe "forward command" do
    it "should recognize a forward command followed by an integer" do
      prog = <<-PROG
        forward 100
      PROG

      Logo.compile(prog).must_equal == [Logo::ForwardNode.new(100)]
    end

    it "should not recognize a forward command when not followed by an integer" do
      prog = <<-PROG
        forward horse
      PROG

      proc { Logo.compile(prog) }.must_raise(StandardError)
    end
  end

  describe "rt" do
    it "should recognize a rt followed by an Integer" do
      prog = <<-PROG
        rt 90
      PROG

      Logo.compile(prog).must_equal == [Logo::RightTurn.new(90)]
    end
  end

  describe "simple function definitions" do
    it "should recognize a function block starting with TO" do
      prog = <<-PROG
        to square
          forward 100
          rt 90
          forward 100
          rt 90
          forward 100
          rt 90
          forward 100
          rt 90
        end
      PROG

      Logo.compile(prog).must_equal == [Logo::Function("square", [
          Logo::ForwardNode.new(100),
          Logo::RightTurn.new(90),
          Logo::ForwardNode.new(100),
          Logo::RightTurn.new(90),
          Logo::ForwardNode.new(100),
          Logo::RightTurn.new(90),
          Logo::ForwardNode.new(100),
          Logo::RightTurn.new(90)])]
    end

    it "should raise an exception if there is not a following END"
  end
end