Exemplos de testes com minitest

exemplo_01.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'minitest' , '~> 5.14', '>= 5.14.2'
end

module Calc
  extend self

  def add(a, b); number(a) + number(b); end
  def sub(a, b); number(a) - number(b); end

  private

    def number(value)
      return value if value.is_a?(Numeric)
      return value.include?('.') ? value.to_f : value.to_i if numeric_string?(value)
      raise TypeError, 'the value must be Numeric or a String with numbers'
    end

    def numeric_string?(value)
      value.is_a?(String) && value =~ /((\d+)?\.\d|\d+)/
    end
end

require 'minitest/autorun'

class CalcAdditionTest < Minitest::Test
  def test_the_operation_with_numeric_values
    assert Calc.add(1, 1) == 2
    assert Calc.add(1.5, 1) == 2.5
  end

  def test_the_operation_with_string_values
    assert Calc.add(1, '1') == 2
    assert Calc.add('1.5', 1) == 2.5
    assert_raises(TypeError) { Calc.add('a', 1) }
  end

  def test_the_operation_with_invalid_args
    assert_raises(TypeError) { Calc.add([], '1') }
    assert_raises(TypeError) { Calc.add('1.5', {}) }
  end
end

exemplo_02.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'minitest' , '~> 5.14', '>= 5.14.2'
end

module Calc
  extend self

  def add(a, b); number(a) + number(b); end
  def sub(a, b); number(a) - number(b); end

  private

    def numeric_string?(value)
      value.is_a?(String) && value =~ /((\d+)?\.\d|\d+)/
    end

    def number(value)
      return value if value.is_a?(Numeric)
      return value.include?('.') ? value.to_f : value.to_i if numeric_string?(value)
      raise TypeError, 'the value must be Numeric or a String with numbers'
    end
end

require 'minitest/autorun'

class CalcAdditionTest < Minitest::Test
  def test_the_operation_with_numeric_values
    assert_equal(2, Calc.add(1, 1))

    assert_in_delta(2.1232, Calc.add(1, 1.1232), 0.01)
  end

  def test_the_operation_with_string_values
    assert Calc.add(1, '1') == 2
    assert Calc.add('1.5', 1) == 2.5
    assert_raises(TypeError) { Calc.add('a', 1) }
  end

  def test_the_operation_with_invalid_args
    assert_raises(TypeError) { Calc.add([], '1') }
    assert_raises(TypeError) { Calc.add('1.5', {}) }
  end
end

class CalcSubtractionTest < Minitest::Test
  def test_the_operation_with_numeric_values
    assert_equal(0, Calc.sub(1, 1))

    assert_in_delta(0.1232, Calc.sub(1.1232, 1), 0.01)
  end

  def test_the_operation_with_string_values
    assert Calc.sub(1, '1') == 0
    assert Calc.sub('1.5', 1) == 0.5
    assert_raises(TypeError) { Calc.sub('a', 1) }
  end

  def test_the_operation_with_invalid_args
    assert_raises(TypeError) { Calc.sub([], '1') }
    assert_raises(TypeError) { Calc.sub('1.5', {}) }
  end
end

exemplo_03.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'minitest' , '~> 5.14', '>= 5.14.2'
end

module Calc
  extend self

  def add(a, b); number(a) + number(b); end
  def sub(a, b); number(a) - number(b); end

  private

    def numeric_string?(value)
      value.is_a?(String) && value =~ /((\d+)?\.\d|\d+)/
    end

    def number(value)
      return value if value.is_a?(Numeric)
      return value.include?('.') ? value.to_f : value.to_i if numeric_string?(value)
      raise TypeError, 'the value must be Numeric or a String with numbers'
    end
end

require 'minitest/autorun'

module Calc
  class AdditionTest < Minitest::Test
    def test_the_operation_with_numeric_values
      assert_equal(2, Calc.add(1, 1))

      assert_in_delta(2.1232, Calc.add(1, 1.1232), 0.01)
    end

    def test_the_operation_with_string_values
      assert Calc.add(1, '1') == 2
      assert Calc.add('1.5', 1) == 2.5
      assert_raises(TypeError) { Calc.add('a', 1) }
    end

    def test_the_operation_with_invalid_args
      assert_raises(TypeError) { Calc.add([], '1') }
      assert_raises(TypeError) { Calc.add('1.5', {}) }
    end
  end

  class SubtractionTest < Minitest::Test
    def test_the_operation_with_numeric_values
      assert_equal(0, Calc.sub(1, 1))

      assert_in_delta(0.1232, Calc.sub(1.1232, 1), 0.01)
    end

    def test_the_operation_with_string_values
      assert Calc.sub(1, '1') == 0
      assert Calc.sub('1.5', 1) == 0.5
      assert_raises(TypeError) { Calc.sub('a', 1) }
    end

    def test_the_operation_with_invalid_args
      assert_raises(TypeError) { Calc.sub([], '1') }
      assert_raises(TypeError) { Calc.sub('1.5', {}) }
    end
  end
end

exemplo_04.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'

  gem 'minitest' , '~> 5.14', '>= 5.14.2'
end

module Calc
  extend self

  def add(a, b); number(a) + number(b); end
  def sub(a, b); number(a) - number(b); end

  private

    def numeric_string?(value)
      value.is_a?(String) && value =~ /((\d+)?\.\d|\d+)/
    end

    def number(value)
      return value if value.is_a?(Numeric)
      return value.include?('.') ? value.to_f : value.to_i if numeric_string?(value)
      raise TypeError, 'the value must be Numeric or a String with numbers'
    end
end

require 'minitest/autorun'

class CalcAdditionTest < Minitest::Test
  def setup
    @numbers = {a: 1, b: 2}
  end

  def teardown
    @numbers.delete(:a)
    @numbers.delete(:b)
  end

  def test_the_operation_with_numeric_values
    assert_equal(3, Calc.add(@numbers[:a], @numbers[:b]))
  end
end