assert output.md

class Hoge
  def output
    p 'a'
  end
end

require "minitest/autorun"
require "./hoge"

class TestHoge < Minitest::Test
  def setup
    @hoge = Hoge.new
  end

  def test_hoge
    assert_output(/a/) { @hoge.output }
  end
end

$ ruby hoge_test.rb
Run options: --seed 55600

# Running:

.

Finished in 0.000906s, 1103.9891 runs/s, 2207.9783 assertions/s.

1 runs, 2 assertions, 0 failures, 0 errors, 0 skips