AllAbout 029 minitest/TDD

asserts.rb

require 'bundler/setup'

require 'socket'
require 'minitest/autorun'

class AssertSamples < Minitest::Test
  def test_asserts
    # 等しいこと
    assert_equal 5, 2 + 3
    # 空(empty?がtrue)であること
    assert_empty []
    # 要素が含まれること
    assert_includes 1..100, 55
    # 正規表現にマッチすること
    assert_match(/\d{4}-\d{2}-\d{2}/, '2015-02-20')
    # nilであること
    assert_nil @my_undefined
    # あるクラスのインスタンスであること
    assert_instance_of Date, Date.parse('2015-02-20')

    # ブロック内のコードが特定の例外を発生させること
    assert_raises SocketError do
      TCPSocket.new 'no-such-hostname.example.com', 888
    end

    # エラーが起こらないこと
    assert_silent do
      TCPSocket.new 'httpbin.org', 80
    end

    # 標準出力(あるいはエラー出力)にある文字列が出ること
    assert_output "egho\n" do
      puts %w(h o g e).sort.join
    end
  end
end

autorun.rb

# require 'minitest/autorun'
require 'minitest'

# ... テストケースの記述

Minitest.autorun

fib.rb

require 'bundler/setup'
require 'minitest/autorun'

def fibonacci(n)
end

class TestFibonacci < Minitest::Test
  def test_fibonacci
    assert_equal 0, fibonacci(0)
  end
end

fib1.rb

require 'bundler/setup'
require 'minitest/autorun'

def fibonacci(n)
end

class TestFibonacci < Minitest::Test
  def test_fibonacci
    assert_equal 0, fibonacci(0)
  end
end

fib1_run.sh

Run options: --seed 40867

# Running:

F

Finished in 0.000895s, 1117.3184 runs/s, 1117.3184 assertions/s.

  1) Failure:
TestFibonacci#test_fibonacci [fib1.rb:9]:
Expected: 0
  Actual: nil

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

fib2.rb

def fibonacci(n)
  0
end

fib2_run.sh

Finished in 0.000979s, 1021.4505 runs/s, 1021.4505 assertions/s.
1 runs, 1 assertions, 0 failures, 0 errors, 0 skips

fib3.rb

# n = 1のテストを追加し...
assert_equal 1, fibonacci(1)

# 0, 1の両方で通るように修正します
def fibonacci(n)
  return 0 if n == 0
  return 1 if n == 1
end

fib_loop.rb

def fibonacci(n)
  return 0 if n == 0
  prev, current = 0, 1
  2.upto(n) do
    prev, current = current, prev + current
  end
  current
end

fib_loop_run.sh

Finished in 0.001011s, 1978.2394 runs/s, 8902.0772 assertions/s.
2 runs, 9 assertions, 0 failures, 0 errors, 0 skips

fib_rec.rb

def fibonacci(n)
  return 0 if n == 0
  return 1 if n == 1
  fibonacci(n - 1) + fibonacci(n - 2)
end

fib_rec_test.rb

class TestFibonacci < Minitest::Test
  def test_fibonacci_init
    assert_equal 0, fibonacci(0)
    assert_equal 1, fibonacci(1)
  end

  def test_fibonacci_n
    assert_equal 1, fibonacci(2)
    assert_equal 2, fibonacci(3)
    assert_equal 3, fibonacci(4)
    assert_equal 5, fibonacci(5)
    assert_equal 8, fibonacci(6)

    assert_equal 55, fibonacci(10)
    assert_equal 102334155, fibonacci(40)
  end
end

first.rb

require 'bundler/setup'
require 'minitest/autorun'

class MyClass
  def add(x, y)
    x + y
  end
end

# Minitest::Testを継承
class TestMyClass < Minitest::Test
  def setup
    @my = MyClass.new
  end

  # test_* にマッチするメソッドを定義
  def test_add
    assert_equal 5, @my.add(2, 3)
  end
end

first_run.sh

$ ruby first.rb

Run options: --seed 14863

# Running:

.

Finished in 0.001392s, 718.3908 runs/s, 718.3908 assertions/s.

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

refute.rb

require 'bundler/setup'
require 'minitest/autorun'

class RefuteSamples < Minitest::Test
  def test_refutes
    refute_equal 6, 2 + 3
    refute_empty [1, 2, 3]
    refute_includes 1..100, 550
    refute_match(/\d{4}-\d{2}-\d{2}/, '2015-2-20')
    refute_nil 123
    refute_instance_of Time, Date.parse('2015-02-20')
  end
end

spec.rb

require 'bundler/setup'
require 'minitest/autorun'

class MySpec
  def mul(x, y)
    x * y
  end
end

describe MySpec do
  before do
    @my = MySpec.new
  end

  it { @my.mul(2, 3).must_equal 6 }

  it '説明テキスト' do
    @my.mul(2, 10).must_equal 20
  end

  # 実はassertで書いても大丈夫
  it { assert_equal 6, @my.mul(2, 3) }
end