CODEWITHSUNDEEP
ruby-on-railsrubyregextesting
Hugs
Hugs

Reputation: 935

regex for Rails assertion to see if path matches

I am trying to do an assertion for a Rails test that tests a method redirects to a certain URL, however the URL is only partially complete for my assertion as I am not entirely sure what the full path will be. Therefore I am trying to write an assertion for the partial path. This is what I have but I'm not very good with regexes.

assert_match /[#{PAYPAL_CONFIG["url"]}]./, @response.redirect_url

I want it to match the paypal path and then whatever comes after that but I am not sure how to get this right. When I use this regex to match i get an error in my test empty range in char class: /[https:\/\/www.sandbox.paypal.com\/cgi-bin\/webscr?]./ I know my regex is wrong where I am trying to match anything after the paypal url. Can someone help me out please?

I can see the [] brackets act as an or what I want is the specified path and anything after that.

I have changed my assertion to this:

/#{PAYPAL_CONFIG["url"]}.*/

My test passes but I get this warning: WARNING: MiniTest::MINI_DIR was removed. Don't violate other's internals. Is my regex ok or not? Thanks

Upvotes: 3

Views: 1262

Answers (1)

Deathbob
Deathbob

Reputation: 1087

You ought to escape the url before you drop it in the regex.

Something like 

/#{Regexp.escape(PAYPAL_CONFIG["url"])}/

would probably be better.

WRT your example, the problem is in the cgi-bin bit. The regex engine expects a hyphen to express a range of characters, and i-b is not a legal range, as there is no character both above i and below b.

The reason the version without the square brackets works is because the regexp engine only interprets hyphens as a range of characters inside the brackets, but the regex itself is still going to be messed up.

>> foo = "https:\/\/www.sandbox.paypal.com\/cgi-bin\/webscr?"
=> "https://www.sandbox.paypal.com/cgi-bin/webscr?"
>> /[#{foo}]/
RegexpError: empty range in char class: /[https:\/\/www.sandbox.paypal.com\/cgi-bin\/webscr?]/
from (irb):2
>> /[#{Regexp.escape(foo)}]/
=> /[https:\/\/www\.sandbox\.paypal\.com\/cgi\-bin\/webscr\?]/
>> Regexp.escape(foo)
=> "https://www\\.sandbox\\.paypal\\.com/cgi\\-bin/webscr\\?"
>> foo
=> "https://www.sandbox.paypal.com/cgi-bin/webscr?"

Upvotes: 2

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