Temporarily set js_errors to false in Poltergeist

Question

I have a set of tests which lead to a Facebook page where the user logs in. Unfortunately, this page has some JavaScript errors which I can't influence, so my tests would never finish.

Is there any way to temporarily disable the check for JS errors? I was thinking about something like: Capybara.javascript_driver.js_errors = false and then setting it to true later, but unfortunately this doesn't work. I have tried variations of this to no avail.

Any ideas on how my problem could be solved?

Ineffective

Can you wrap test code to try{}catch(e){} block? I mean the part where Facebook page opens. Or tests itself not written in javascript? – Handful

Answer 1

Thanks to Roman Pominov's comment I was able to find a solution. It was actually quite simple:

I just added rescue Capybara::Poltergeist::JavascriptError after the statement in question, and then it worked like a charm. My initial idea was too complicated ;)

Ineffective

what was your initial idea? I have a large number of tests so disabling the js_errors in a before/after block is much preferable to adding rescue statements to each test – Lankester

Well, if possible, I would suggest to deal with all JS errors (they are errors, after all). If not possible, I would stick to rescue. My initial idea was described in the question, as far as I remember. Is it possible to solve those JS errors? – Ineffective

Ah my bad, I thought maybe you had another idea that you had removed on an edit. And its a JS error that's throwing in an external service? I guess my bigger problem is that I have a feature spec visiting an external service in the first place. – Lankester

Keep in mind this could roll back any operation that was running when the error happened i.e. I had log in form not submit when I caught the error js error from it. – Acromegaly

YOu made my day! ;) – Donnelldonnelly

Answer 2

This makes the trick:

page.driver.browser.js_errors = false

---

You may also add around callback:

# spec_helpers.rb
config.around(:each) do |example|
  original_value = page.driver.browser.instance_variable_get(:@js_errors)
  if example.metadata.has_key?(:js_errors)
    page.driver.browser.js_errors = example.metadata[:js_errors]
  end

  example.run

  page.driver.browser.js_errors = original_value
end

In your tests:

# my_feature_spec.rb
it "should ignore errors", js_errors: false do
  ...
end

Opposable

This would not work if you have non-request specs, right? Is page going to be defined for other specs? – Piccaninny

Note that if you're taking this approach in eg Cucumber, then JS errors will remain disabled for all subsequent tests as well! – Helpmeet