Ruby Minitest method call assertion examples

personal_note.rb

class PersonalNote
  def initialize(note)
    @note = note
  end

  def update
    @note.update
  end
end

personal_note_test.rb

require 'minitest/autorun'

class FakeNote
  def initialize
    @updated = false
  end

  def update
    @updated = true
  end

  def updated?
    @updated
  end
end

class PersonalNoteTest < Minitest::Test
  def test_update_using_mock
    mock = Minitest::Mock.new
    mock.expect(:update, nil)

    p_note = PersonalNote.new(mock)
    p_note.update

    assert_mock mock
  end

  def test_update_using_fake
    note = FakeNote.new

    pnote = PersonalNote.new(note)
    pnote.update

    assert note.updated?
  end
end

pg_note.rb

class PgNote
  def update(text); end
  def owned_by?(user); end
end