spec.rb

describe "Asm" do
  it "runs an empty program" do
    Asm.asm do
    end.should eq [0, 0, 0, 0]
  end

  it "divides positive numbers" do
    Asm.asm do
      mov ax, 37
      mov bx, 6
      mov dx, ax
      label looper
      inc cx
      dec dx, bx
      cmp dx, bx
      jg looper
    end.should eq [37, 6, 37 / 6, 37 % 6]
  end

  it "finds modulus" do
    Asm.asm do
      mov ax, 3
      mov bx, 0
      mov cx, -3
      cmp ax, 0
      jg ax_positive
      dec dx, ax
      mov ax, dx
      label ax_positive
      cmp bx, 0
      jg bx_positive
      mov dx, 0
      dec dx, bx
      mov bx, dx
      label bx_positive
      cmp cx, 0
      jg cx_positive
      mov dx, 0
      dec dx, cx
      mov cx, dx
      label cx_positive
      mov dx, 0
    end.should eq [3.abs, 0.abs, -3.abs, 0]
  end
end