How should we test an rjs response in Rails Functional tests? - ruby-on-rails

How can I test a .js.rjs response in rails(2.3.8) functional test ?

You can take the simple path and verify the contents being returned seem correct with a functional test.
However, you'll probably get a lot more value from something like Capybara and Celerity that will let you do real integration testing with a live JavaScript engine and verify the RJS causes the page behave you expect.
http://github.com/jnicklas/capybara/blob/master/README.rdoc

There's assert_select_rjs in case you weren't aware of it (like I was). Its something like an assert_tag for RJS output.

Related

Outputting HTTP request/response data with RSpec

I have a rails project that serves a JSON API with tests written in RSpec. Often when running specs (request specs, specifically), I’m interested in seeing some details about the HTTP request/response...i.e. the request URL, request body, and response body, ideally JSON pretty-formatted for readability. This isn't for the purposes of documentation but rather as part of the development / debugging process.
I have a helper method I wrote which does this...you just drop a method call into your spec and it prints this stuff out.
But, seems like it would be better if there was a switch that’s part of the running specs. RSpec has custom formatters which I thought might be the right direction, but in trying to build one, I can't figure out how to get access to the request/response objects like you can from inside of your spec.
How can I access the request/response objects in my custom RSpec formatter? Or, perhaps another way to approach the problem?
Here's an approach:
Assuming a rails project, in spec_helper.rb, define a global "after" hook like so:
config.after(:each) do #runs after each example
if ENV['PRINTHTTP']
#use request/response objects here, e.g. puts response.status
end
end
Then, you can conditionally enable by adding the environmental variable on the command-line:
$ PRINTHTTP=1 rspec

Test rendering of Rails template

Wrong use of .t method in Rails template such
<%= (user.score).t(:context => 'foo') %>
Causes an error
undefined method `t' for 46:Fixnum
The method was called on number.
Now the question is how can this situation can be tested? Where the test code should live, so all the templates will be tested before rendering?
It depends on your choice of testing framework. With the Test::Unit stuff that comes with rails your controller and integration tests render views and so should catch this sort of error. Other forms of integration testing, such as cucumber should also pick up such things.
If you use rspec then you can write view specs: specs that test view rendering in isolation.
Lastly if you find yourself with lots of logic in your views that you want to test, you're probably better off extracting that logic into a helper and writing unit tests/specs for that helper.
AFAIK you don't test the templates itself. But you can test e.g. with cucumber if you get the view results you are expecting. This could be some sort of "template testing".

Using rspec to test code prone to external infuence

I'm using rspec to test a code that may fail depending on the change of a site structure (the external influence I mentioned). I would like to write an example that involves "should raise an error" but I'm not sure if rspec is the right tool to test code in such situations. Could someone point me in some direction?
Thanks in advance
You could write custom matchers
Something like :
site.should_have_valid_structure
Spec::Matchers.define :have_structure
match do |actual|
actual.structure == Site::VALID_STRUCTURE
end
end
Mock the external influence so you can test it properly (if the external influence is a Web page or other HTTP request, WebMock and VCR are great for this). Your tests should not rely on anything external functioning properly -- or improperly. See http://marnen.github.com/webmock-presentation/webmock.html for an overview I wrote last year.

How can I see what actually happens when a Test::Unit test runs?

In a Rails application I have a Test::Unit functional test that's failing, but the output on the console isn't telling me much.
How can I view the request, the response, the flash, the session, the variables set, and so on?
Is there something like...
rake test specific_test_file --verbose
You can add puts statements to your test case as suggested, or add calls to Rails.logger.debug() to your application code and watch your log/development.log to trace through what's happening.
In your test you have access to a bunch of resources you can user to debug your test.
p #request
p #response
p #controller
p flash
p cookie
p session
Also, remember that your action should be as simple as possibile and all the specific action execution should be tested by single Unit test.
Functional test should be reserved to the the overall action execution.
What does it mean in practice? If something doesn't work in your action, and your action calls 3 Model methods, you should be able to easily isolate the problem just looking at the unit tests. If one (or more) unit test fails, then you know which method is the guilty.
If all the unit tests pass, then the problem is the action itself but it should be quite easy to debug since you already tested the methods separately.
in the failing test use p #request etc. its ugly, but it can work
An answer to a separate question suggested
rake test TESTOPTS=-v
The slick way is to use pry and pry-nav gems. Be sure to include them in your test gem group. I use them in the development group as well. The great thing about pry and pry nav is you can step through your code with a console, so you can not only see the code as it's executed, but you can also enter console commands during the test.
You just enter binding.pry in the places in the code you want to trigger the console. Then using the 'step' command, you can move line by line through the code as it's executed.

In rails, how do you stub the render method in functional tests?

I'm writing some functional tests for a controller in rails, using mocha to do mocking/stubbing.
Is there a way to prevent the template from being rendered during the test, so that I can test only the code in the controller?
It looks like rspec provides something like this, but I'm not using rspec.
The most obvious solution seems to work:
#controller.expects(:render)
I could have sworn that I tried that last night with no luck. But this morning it works like a charm. I must have overlooked a typo.
It doesn't look like using stub is necessary here. If you want to make sure that a given template is rendered, use assert_template and/or assert_response. You can also assert a state of the response object, either by hand or using helpers like assert_select.
Would render_to_string do what you need?

Resources