ruby-on-rails - Rspec should match is false 但 eq 应该为真吗？

Question

谁能给我解释一下为什么会这样？

get :robots
response.should render_template("no_index")
response.body.should match "User-agent: *\nDisallow: /\n"

Failure/Error: response.body.should match "User-agent: *\nDisallow: /\n"
  expected "User-agent: *\nDisallow: /\n" to match "User-agent: *\nDisallow: /\n"
# ./spec/controllers/robots_controller_spec.rb:12:in `block (3 levels) in <top (required)>'

但是

get :robots
response.should render_template("no_index")
response.body.should eq "User-agent: *\nDisallow: /\n"

通过？

这似乎相关(irb):

1.9.2p318 :001 > "User-agent: *\nDisallow: /\n".match "User-agent: *\nDisallow: /\n"
=> nil 

Answer 1

这对我来说似乎是非常*出乎意料的行为，但我已经解决了这个问题。 String#match 的 Ruby 文档说

Converts pattern to a Regexp (if it isn’t already one)

但这种“转换”似乎只是将“foo”更改为/foo/，没有进行任何转义或任何操作。所以，例如，

1.9.2p318 :014 > "User-agent: *\nDisallow: /\n".match /User-agent: \*\nDisallow: \/\n/
=> #<MatchData "User-agent: *\nDisallow: /\n"> 

如果您使用单引号但为特殊正则表达式字符添加转义符，则字符串匹配也有效:

1.9.2p318 :015 > "User-agent: *\nDisallow: /\n".match 'User-agent: \*\nDisallow: \/\n'
 => #<MatchData "User-agent: *\nDisallow: /\n">

但是，如果你使用双引号，它仍然不起作用，因为换行符:

1.9.2p318 :013 > "User-agent: *\nDisallow: /\n".match "User-agent: \*\nDisallow: \/\n"
=> nil 

!!!!