ruby - 为什么在不同的单元测试中访问此实例变量时为 nil？

Question

require 'rubygems'
require 'test/unit'

class Thing
  attr_accessor :foo

  def set_stuff
    @foo = 'bar'
  end
end

class ThingTest < Test::Unit::TestCase
  def setup
    @thing = Thing.new
  end

  def test_set_stuff
    @thing.set_stuff
    assert 'bar' == @thing.foo
  end

  def test_foo_in_other_test
    puts @thing.foo
    assert 'bar' == @thing.foo
  end
end


# Loaded suite testing
# Started
# nil
# F.
# Finished in 0.00439 seconds.
#
#   1) Failure:
# test_foo_in_other_test(ThingTest) [testing.rb:26]:
# <false> is not true.
#
# 2 tests, 2 assertions, 1 failures, 0 errors

Answer 1

不同之处在于您没有在第二个测试中调用 @thing.set_stuff。