tests.rb

# Standard function
def divide param_x, param_y
  return Infinity if param_y.zero?
  param_x.to_f / param_y.to_f
end

# Doable implementation with tests block in-function
def divide_with_tests param_x, param_y
  return Infinity if param_y.zero?
  param_x / param_y.to_f

  tests do
    assert self(0, 3) == 0
    assert self(6, 3) == 2
    assert self(3, 0) == Infinity
  end
end

# Ideal implementation with tests in a separate block than method code
def divide_with_tests param_x, param_y
  return Infinity if param_y.zero?
  param_x / param_y.to_f
tests
  assert self(0, 3) == 0
  assert self(6, 3) == 2
  assert self(3, 0) == Infinity
end