How do I easily parse a URL with parameters in a Rails test?

Question

I have a some code that embeds a return_to URL into a redirect (like OpenID) that I want to test:

def test_uses_referrer_for_return_to
  expected_return_to = 'http://test.com/foo'
  @request.env['HTTP_REFERER'] = expected_return_to
  get :fazbot
  # @response.redirected_to looks like http://service.com?...&return_to=[URI-encoded version of URL above]&...
  encoded_return_to = (something_here)[:return_to]
  assert_equal expected_return_to, URI.unencode(encoded_return_to)
end

It's a Rails ActionController::TestCase, so I have access to all sorts of helper methods; I just can't find the right one.

Of course I could use URI.parse to get the params part of the URL, then split it on /&|?/ and then split again on '=', but I'm hoping this is already done for me. Plus, what if I miss some obscure rule in URL escaping or parameter parsing? There has to be something in ActionPack or ActiveSupport to do this, but I can't find it.

Thanks :)

score 43 · Accepted Answer · answered May 27 '09 at 15:25

43

CGI::parse(querystring) will parse a querystring into a hash. Then, CGI::unescape(string) will undo any URL-encoding in the value.

Alternatively, you can use Rack::Utils.parse_query and Rack::Utils.unescape if you're on a recent Rack-based version of Rails, and want to be super-modern.

I'm not aware of any Rails-specific helper methods that wrap these utility functions, but they're pretty simple to use, and CGI or Rack is already loaded in the Rails environment anyway.

answered May 27 '09 at 15:25

chrismear

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CGI::parse wraps all values in an array. +1 for Rack::Utils.parse_query – zaius Jul 24 '10 at 21:50
CGI::parse handles bad characters you sometimes see in URLs, rack parse_query will fail on {,},',", ... – Dark Castle Mar 24 '12 at 06:18
3

If you have nested query, give it a try to `Rack::Utils.parse_nested_query(q)`: `Rack::Utils.parse_nested_query 'foo=1&bar%5Bbaz%5D=baz'` => `{"foo"=>"1", "bar"=>{"baz"=>"baz"}}` – sequielo Oct 30 '13 at 19:08
1

on ruby 2.2 I see `CGI::parse` doing automatic URL decoding so the extra `unescape` can do double the work and in edge cases produce wrong results – akostadinov Dec 28 '15 at 19:28

score 29 · Answer 2 · edited Dec 18 '14 at 15:23

29

You want Addressable for this.

uri = Addressable::URI.parse("http://example.com/?var=value")
uri.query_values # => {"var"=>"value"}
uri.query_values = {"one" => "1", "two" => "2"}
uri.to_s # => "http://example.com/?two=2&one=1"

It'll automatically handle all the escaping rules for you, and it has some other useful features, like not throwing exceptions for perfectly valid but obscure URIs like the built-in URI parser.

edited Dec 18 '14 at 15:23

uday

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answered Jun 03 '09 at 15:12

Bob Aman

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You are biased as the maintainer, I am not and would rather use this then anything else. Wonderful gem, thanks for making it happen. – Kjellski Jan 30 '13 at 11:25
1

Thanks for the kind words. It's been quite a few years of hard work building and improving it. – Bob Aman Feb 04 '13 at 09:00
Addressable is a replacement for the URI implementation that is part of Ruby's standard library. Addressable works in Ruby 1.8.x, 1.9.x, and JRuby. – Misha Mar 25 '15 at 21:03

How do I easily parse a URL with parameters in a Rails test?

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