ruby-on-rails - Ruby on Rails 单元测试在日期测试中失败

Question

Ruby/Rails 的一些单元测试正则表达式问题。

运行:

• rails 4.0.0
• ruby 2.0.0-p247
• RVM 1.23.5
• Mac 操作系统 10.8.5

编写一个 applicaton_helper 方法，该方法将根据日期的时间来格式化日期。方法如下:

module ApplicationHelper
  def humanize_datetime time
    time = Time.at(time)
    date = time.to_date

    today   = Date.today

    time_format = "%-I:%M %p"

    #if the time is within today, we simply use the time
    if date == today
      time.strftime time_format

    # if  the time is within the week, we show day of the week and the time
    elsif today - date < 7
      time.strftime "%a #{time_format}"

    # if time falls before this week, we should the date (e.g. Oct 30)
    else
      time.strftime "%b %e"
    end
  end
end

这似乎给出了预期的结果，但由于某种原因，以下测试失败了:

require 'test_helper'

class ApplicationHelperTest < ActionView::TestCase

  test "humanize_dateime should display only time when datetime is within today" do
    formatted = humanize_datetime Time.now
    assert_match /\A\d{1,2}\:\d\d (AM|PM)\z/, formatted
  end

  test "humanize_datetime should display day of week and time when datetime is not today but within week" do
    yesterday_formatted = humanize_datetime (Date.today - 1).to_time # yesterday
    assert_match /\A[a-zA-z]{3} \d{1,2}\:\d\d (AM|PM)\z/, yesterday_formatted

    within_week_formatted = humanize_datetime (Date.today - 6).to_time # just within this week
    assert_match /\A[a-zA-z]{3} \d{1,2}\:\d\d (AM|PM)\z/, within_week_formatted
   end

   test "humanize_datetime should display date when datetime is before this week" do
     last_week_formatted = humanize_datetime (Date.today - 7).to_time
     assert_match /\A[a-zA-Z]{3} \d{1,2}\z/, last_week_formatted
   end
end

最后一次测试失败，给出

1) 失败:ApplicationHelperTest#test_humanize_datetime_should_display_date_when_datetime_is_before_this_week [/Users/mohammad/rails_projects/stopsmoking/test/helpers/application_helper_test.rb:20]:预期/\A[a-zA-Z]{3}\d{1,2}\z/匹配“Oct 8”。

这真的很奇怪，因为正则表达式对我来说看起来没问题，而且我已经在 http://rubular.com/ 上测试了表达式.这里的所有其他测试都通过了。我还尝试删除字符串定界符的开头/结尾以及 \d 之后的量词。

关于为什么会发生这种情况有什么想法吗？

Answer 1

如果日期 < 10，你的 humanize_datetime 会添加一个额外的空格，因为 "%b %e"。结果字符串不是 "Oct 8"，而是 "Oct 8"。

您应该使用 "%b %-d" 或更改您的正则表达式。

编辑:减号前缀可能不适用于所有系统，参见 this回答更多详情。