Mobile apps still need automated tests

Jonathan Rasmusson recently wrote what I consider to be quite a contentious blog post about iOS application development titled “It’s not about the unit tests”.

“…imagine my surprise when I entered a community responsible for some of the worlds most loved mobile applications, only to discover they don’t unit test. Even more disturbing, they seem to be getting away with it!”

Whilst I agree with the general theme of the blog post which is change your mind, challenge assumptions:

“All I can say is to keep growing sometimes we need to challenge our most cherished assumptions. It doesn’t always feel good, but that’s how we grow, gain experience, and turn knowledge into wisdom.”

“The second you think you’ve got it all figured out you’ve stopped living.”

I don’t agree with the content.

Jonathan’s basic premise is that you can get away with little or no unit testing for your iOS application for a number of reasons including developing for a smaller screen size, no legacy, one language, visual development and developing on a mature platform. But the real reason that iOS get away with it is by caring.

“These people simply cared more about their craft, and what they were doing, than their contemporaries. They ‘out cared’ the competition. And that is what I see in the iOS community.”

But in writing this post, I believe he missed two critical factors when deciding whether to have automated tests for your iOS app.

iOS users are unforgiving

If you accidentally release an app with a bug, see how quickly you’ll start getting one star reviews and nasty comments in the App Store. See how quickly new users will uninstall your app and never use it again.

The App Store approval process is not capable of supporting quick bug fixes

Releasing a new version of your app that fixes a critical bug may take you 2 minutes (you don’t even need to fix a broken test or write a new test for it!) but it then takes Apple 5-10 business days to release it to your users. This doesn’t stop the one star reviews and comments destroying your reputation in the meantime.

Case in Point: Lasoo iPhone app

I love the Lasoo iPhone app, because it allows me to read store catalogs on my phone (I live in an apartment block and we don’t get them delivered). Recently I upgraded the app and then tried to use it but it wouldn’t even start. I tried the usual close/reopen, delete/reinstall but still nothing. I then checked the app store:

Lasoo iPhone app reviews
Lasoo iPhone app reviews

Oh boy, hundreds of one star reviews within a couple of days: the app is stuffed! I then checked twitter to make sure they knew it was broken, and to my surprise they’d fixed it immediately but were waiting for Apple to approve the fix.

I can’t speculate on whether Lasoo care or not about their app, but imagine for a second if they had just one automated test, one automated test that launched the app to make sure it worked, and it was run every time a change, no matter how small, was made. That one automated test would have saved them from hundreds of one star reviews and having to apologize to customers on twitter whilst they waited for Apple to approve the fix.

Which raises another point:

“[Apple] curate and block apps that don’t meet certain quality or standards.”

The Lasoo app was so broken it wouldn’t even start, so how did it get through Apple’s approval process for certain quality or standards?

Just caring isn’t enough to protect you from introducing bugs

We all make mistakes, even if we care. That’s why we have automated tests, to catch those mistakes.

Not having automated tests is a bit like having unprotected sex. You can probably get away with it forever if you’re careful, but the consequences of getting it wrong are pretty dramatic. And just because you can get away with it doesn’t mean that other people will be able to.

Roll your own page objects

There seems to be a lot of focus being put into page object ruby gems at the moment. Cheezy has done a fantastic job of the aptly named page-object that supports Watir-Webdriver and Selenium-Webdriver, and then there’s the more recent site_prism (also fantastic) by Nat Ritmeyer that works with Capybara. Before these two came along, I even wrote my own; the now retired watir-page-helper gem.

The premise of these gems is they make it super easy to create page objects for your ruby automated testing projects. But today I want to discuss another crazy idea with you: do you even need a gem at all to do page objects?

Background

I recently refactored some automated tests that Chris McMahon wrote as a potential framework for Wikimedia Foundation (creators of Wikipedia). Chris’s code used Cheezy’s excellent page-object gem so I happily went about my refactoring his code using that gem. Suddenly… I found instead of helping me it started to hinder me. I kept having to refer to page-object user guide I got from Cheezy in Austin to work out how things work. Namely:

  1. How to define elements: as they are different from watir-webdriver (eg. list_item vs li, cell vs td etc.)
  2. How to identify elements: as they are limited to certain supported attributes by element type, unlike watir-webdriver which supports every attribute for all elements
  3. What methods each element provides and what each does: as different elements create different methods with different behaviours, so calling a link element clicks it, whilst a span element returns its text.

The main problem I personally found was that Page-object has essentially created its own DSL to describe elements in page objects, and this DSL is subtly and not so subtly different from the Watir-Webdriver API, so the API I know and love doesn’t work in a lot of places.

An example. There’s a common menu bar on all the Wikimedia sites that displays the logged in user as a link (to the user’s page).

The link is only recognizable by its title attribute, and whilst this is supported by watir-webdriver (it supports any attribute), it is not supported by page-object. The source html looks like:

<a class="new" accesskey="." title="Your user page [ctrl-.]" href="/wiki/User:Alister.scott">Alister.scott</a>

What I would have liked to do was:

  link :logged_in_as, :title => 'Your user page [ctrl-.]'

But, instead, I had to do this (which isn’t very DRY):

  def logged_in_as
    @browser.link(:title => 'Your user page [ctrl-.]').text
  end

I believe essentially what has happened is the page-object, in its neutrality between selenium-webdriver and watir-webdriver, has created its own DSL that is somewhat of a halfway point between the two. This is probably fine for most people starting out, it’s just an API to learn, but for someone like me who has extensive experience with the watir-webdriver API (and loves the power of it), I find it limiting. This is particularly evident when I write a majority of my code using the watir-webdriver API under IRB.

So, I had to take a re-think. Why not roll my own page objects for Wikimedia Foundation?

Roll your own page objects

I recently had a discussion with a colleague/good friend about page objects which went along the lines of “I don’t understand those page object gems because you end up writing a custom page object pattern for each project anyway, as every project/application you work on is different in its own way”. It was one of those aha moments for me.

What I needed was to roll my own Wikimedia page objects.

Taking it back to basics, essentially there are three functions I see a page object pattern provides:

  1. Ability to easily instantiate pages in a consistent manner;
  2. Ability to concisely describe elements on a page, keep it DRY by avoiding repetition of element identifiers (using the underlying driver’s API); and
  3. Ability to provide higher level methods that use the elements to perform user oriented functions.

You can probably notice the helper methods – the magic – that gems like page-object and site_prism provide are missing from my list. This is on purpose, and is because, after lots of thought, I actually don’t find these useful, as they encourage specifications/steps to be too lower level. I would rather a high level method on the page (eg. login) than exposing my username and password fields and a login button.

A Wikimedia Page Model

Taking those things into consideration: this is the page model I came up with for Wikimedia.

Generic Base Page Class

The generic base page class is what everything else extends. It contains the instantiation code common to all pages, and the class methods needed to define elements and methods (more on these later).

Wikimedia Base Page Class

This page class contains elements and methods that are common to all Wikimedia pages. The ‘logged in user’ example above is a good example of something that is the same on every Wikimedia page, whether you’re on Wikipedia, or Wikimedia Commons etc.

Commons & Wikipedia Base Page Classes

These two classes are placeholders for elements and methods are common to a particular site. At the moment with my limited examples, these don’t contain content.

Commons & Wikipedia Page Classes

These are the actual pages that are representations of pages in Wikimedia. These are in separate modules so they are in different namespaces (you can have a Wikipedia::LogonPage and a Commons::LogonPage).

Some example pages:

class Wikipedia::LogoutPage < Wikipedia::BasePage
  page_url "#{Wikipedia::BASE_URL}/w/index.php?title=Special:UserLogout"
  expected_title "Log out - #{Wikipedia::TITLE}"

  element(:main_content_div) { |b| b.div(id: 'mw-content-text' ) }
  value(:main_content) { |p| p.main_content_div.text }
end

Here we can see we define a page_url and expected_title, which are used to instantiate the page.

Next we define an element passing in a block of watir-webdriver code for it, and a value by referencing the element we defined before it. Since these element and value methods execute blocks against self, and the class delegates missing methods to our browser, we can refer to either the browser (shown as b) or the page class (shown as p) in our blocks.

class Commons::LoginPage < Commons::BasePage
  page_url "#{Commons::BASE_URL}/w/index.php?title=Special:UserLogin"
  expected_title "Log in / create account - #{Commons::TITLE}"

  login_elements
  value(:logged_in?) { |p| p.logged_in.exists? }

  def login_with username, password
    username_field.set username
    password_field.set password
    login_button.click
  end
end

In this example, we again define the page_url and expected_title, but we have stored the login_elements with the WikimediaBasePage (as they are the same across all the sites) so we include them by specifying login_elements. We have also defined a login_with method that performs actions on our elements.

There are three available methods to define page elements, values and actions, and these all follow the same format of specifying the method name, and passing in a block of watir-webdriver code.

Calling the page objects from Cucumber step definitions

I chose to use Cucumber for the Wikimedia Foundation framework over Chris’s choice of RSpec as I find it easier to specify end-to-end tests in this way. I find the Cucumber step definitions encourage reuse of steps typically used to set up a test (that are often duplicated in RSpec).

I try to stick to calling the exposed methods, values or actions instead of the elements themselves from my Cucumber steps to ensure I am writing them at a high level. An example step using the page above looks like:

Given /^I am logged into Commons$/ do
  visit Commons::LoginPage do |page|
    page.login_with Commons::USERNAME, Commons::PASSWORD
    page.should be_logged_in
  end
end

The visit and on methods are defined in a Pages module that is mixed into the Cucumber World so these available on all step definitions. As named, the visit method instantiates and visits the page, whereas the on just instantiates it.

module Pages
  def visit page_class, &block
    on page_class, true, &block
  end

  def on page_class, visit=false, &block
    page = page_class.new @browser, visit
    block.call page if block
    page
  end
end

Summary

That’s all there really is the rolling your own page objects. I found this excercise useful as it gives me maximum flexibility and allows me to clearly define pages how I want to define them. I appreciate all the great work that Cheezy and Nat have done on their page object gems, if anything these contain great inspirations on how to roll your own custom page objects most suited to your environment and applications.

You can check out my full code here on Github.