brainfuck_test.exs

defmodule BrainfuckTest do
  use ExUnit.Case
  import BF

  @doc "
  	BF is our Brainfuck turing machine
  	Output will be a map
  	%{
		tape: map #our tape, in the format %{0=> 0, 1=> 0, 2=> 0 ...}
		ptr: int, #pointer position
		output: string #brainfuck output
  	}
  "

  test "moves right" do
    assert (BF.new() |> BF.run(">")).ptr == 1
  end

  @tag :pending
  test "moves left" do
  	assert (BF.new() |> BF.run(">><")).ptr == 1
  end

  @tag :pending
  test "doesnt overflow moving left" do
  	assert (BF.new() |> BF.run("<")).ptr == 0
  end

  @tag :pending
  test "increments at pointer" do
  	assert (BF.new() |> BF.run("+")).tape[0] == 1
  end

  @tag :pending
  test "decrements at pointer" do
  	assert (BF.new() |> BF.run("++-")).tape[0] == 1
  end

  @tag :pending
  test "doesnt overflow decrements" do
  	assert (BF.new() |> BF.run("-")).tape[0] == 0
  end

  @tag :pending
  test "doesnt overflow increments" do
  	code = String.duplicate("+", 300)
  	assert (BF.new() |> BF.run(code)).tape[0] == 255
  end

  @tag :pending
  test "outputs oi" do
  	code = String.duplicate("+", 104) 
  		<> ".>" 
  		<> String.duplicate("+", 105)
  		<> "."
  	assert (BF.new() |> BF.run(code)).output == "hi"
  end

  @tag :pending
  test "loops" do
  	code = "++++[>+<-]"
  	assert (BF.new() |> BF.run(code)).tape[1] == 4
  end

  @tag :pending
  test "hello world" do
  	code = "++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++."
  	assert (BF.new() |> BF.run(code)).output == "Hello World!"
  end
end