How to not repeat yourself in Cucumber scenarios

It is good programming practice to Don't Repeat Yourself (or DRY). In Ruby on Rails we keep our code DRY by sharing behavior by using inheritance, modules, traits or partials.

When you reuse behavior you want to reuse tests as well. You are probably already reusing examples in unit tests. Unfortunately it is much harder to reuse code when writing integration tests with Cucumber, where you need to...

Geordi: Choose your firefox version for cuc

Geordi 0.16+ supports running selenium tests with project-specific firefox versions.

Just update the gem. It will still default to using the old 5.0.1 firefox. If you want another one, add a file .firefox-version to your project, containing your preferred version.

geordi cucumber will prompt (and guide) you to install the given version. You can delete any old installation sitting in /opt/firefox-for-selenium if you have one.

Implementing social media "like" buttons: Everything you never wanted to know

So you client has asked you to implement a row of buttons to like the URL on Facebook, Twitter and Google+. Here are some things you should know about this.

0. Security considerations

Each "like" button is implemented by including a Javascript on your site. This means you are running fucking remote code on your page. You are giving Facebook, Twitter and Google+ full permission to e. g. copy user cookies. Check with your client if she is cool with that. Also note that if you're site is suggesting security by operating under HTTPS ...

Enable CSRF protection in Javascript tests

You might not know that Rails disables CSRF protection in tests. This means that if you accidentally forget to send the CSRF token for non-GET requests, your tests will be green even though your application is completely broken (a failed CSRF check usually logs out the user). Rails probably does this because CSRF protection sort of requires Javascript.

You want to enable CSRF protection in Cucumber scenarios that can speak Javascript. To do so, copy the a...

Cucumber: Detect if the current Capybara driver supports Javascript

Copy the attached file to features/support. This gets you a convenience method:

Capybara.javascript_test?

Is true for Selenium, capybara-webkit, Poltergeist and a custom driver called :chrome (which we sometimes like to use for Selenium+Chrome).

Similar sounding but completely different card: Detect if a Javascript is running under Selenium WebDriver (with Rails)

Disable text-transforms in Selenium tests

Using text-transform: uppercase - especially on form labels - can cause you serious headaches in Selenium tests. Sometimes the web driver will see the uppercase text, sometimes it won't, and umlauts will be a problem as well.

Simply disable it in tests, by

  • adding a body class for tests

    %body{'data-environment' => Rails.env}
    
  • overriding the transforms

    [data-environment="test"] *
      text-transform: none !important
    

Understanding AngularJS service types

Angular comes with different types of services. Each one with its own use cases.

All of these services are singletons. You probably want to use Factory all the time.

Provider

  • is the parent of all other services (except constant)
  • can be configured using `app.config(function(Provider) { ...})
  • a little complex

Factory

  • simpler than Provider, but without configuration
  • definition: `app.factory('name', someFunction)
  • someFunction is called when the name service is instantiated and should return an object

Se...

Compiling Javascript template functions with the asset pipeline

The asset pipeline (which is actually backed by sprockets) has a nice feature where templates ending in .jst are compiled into Javascript template functions. These templates can be rendered by calling JST['path/to/template'](template: 'variables'):

<!-- templates/hello.jst.ejs -->
<div>Hello, <span><%= name %></span>!</div>

// application.js
//= require templates/hello
$("#hello").html(JST["templates/hello"]({ name: "Sam" }));

Whatever is in the <% ... %> is evaluated in Javascript...

Capybara: Trigger requests with custom request method

Preface: Normally, you would not need this in integrations tests (probably that's why it is so hard to achieve), because it is no actual "integration testing". If you use this step, know what you are doing.


Destroying a record with Capybara is not as easy as calling visit user_path(user, method: :delete), because RackTest's visit can only perform GET requests.

With this step you can destroy a records using either Selenium or RackTest. Ex...

Consul 0.10.0 allows multiple power mappings for nested resources

Consul 0.10.0 now allows multiple power mappings for nested resources.


When using nested resources you probably want two power
checks and method mappings: One for the parent resource, another for the child resource.

Say you have the following routes:

resources :clients do
  resources :notes
end

And the following power definitions:

class Power
  ...

  power :clients do
    Client.active if si...

RSpec: Where to put custom matchers and other support code

Custom matchers are a useful RSpec feature which you can use to DRY up repetitive expectations in your specs. Unfortunately the default directory structure generated by rspec-rails has no obvious place to put custom matchers or other support code.

I recommend storing them like this:

spec/support/database_cleaner.rb
spec/support/devise.rb
spec/support/factory_bot.rb
spec/support/vcr.rb
spec/support/matchers/be_allowed_access.rb
s...

RSpec: Where to put shared example groups

Shared example groups are a useful RSpec feature. Unfortunately the default directory structure generated by rspec-rails has no obvious place to put them.

I recommend storing them like this:

spec/models/shared_examples/foo.rb
spec/models/shared_examples/bar.rb
spec/models/shared_examples/baz.rb
spec/controllers/shared_examples/foo.rb
spec/controllers/shared_examples/bar.rb
spec/controllers/shared_examples/baz.rb

To ma...

Rails: Disable options of a select field

Simply give the select helper an option :disabled, passing either a single value or an array. You need to specify the option's value, not its text.

= form.select :country, Address.countries_for_select, :include_blank => true, :disabled => ['disabled-value1', 'disabled-value-2']

Also see Cucumber: Check if a select field contains a disabled option on how to test this.

Cucumber: Check if a select field contains a disabled option

For Capybara, use this step:

Then /^"([^"]*)" should be a disabled option for "([^"]*)"(?: within "([^\"]*)")?$/ do |value, field, selector|
  with_scope(selector) do
    field_labeled(field).find(:xpath, ".//option[text() = '#{value}'][@disabled]").should be_present
  end
end

Automated "git bisect" will make your day

So you're hunting down a regression (or just a bug) and want to use git bisect to find out when it was introduced? Smart kid.
If you have a shell command ready to reveal if your current state is good or bad, you can have git do most of the work for you.

Using git bisect run <your command> you can tell git that your command will reveal the issue; git on the other hand will use the return value of that call to decide if the state is good or bad.
...

MySQL: Careful when using database locks in transactions

We tend to use database transactions as a magic bullet to get rid of all our concurrency problems. When things get really bad, we might even throw in some locking mechanism, but then are usually done with it.

Unfortunately, transactions semantics in databases are actually very complicated, and chances are, your making some incorrect assumptions.

The MySQL innodb engine actually has [four different modes](ht...

Consul 0.9 lets you optimize records checks

Consul 0.9 comes with many new features to optimize powers that only check access to a given record. e.g. Power.current.post?(Post.last). See below for details.

Powers that only check a given object

Sometimes it is not convenient to define powers as a collection. Sometimes you only want to store a method that
checks whether a given object is accessible.

To do so, simply define a power that ends in a question mark:

class Power
  ...

  power :upd...

ActionView::Template::Error (dump format error for symbol(0x6d))

I recently encountered the error above when I was running selenium tests.

Thanks to a post on stackoverflow I found out that clearing all files in tmp/cache in my project folder made the issue go away.

Switch to a recently opened tab with Cucumber

Similar to closing an opened browser window, spreewald now supports the I switch to the new browser tab step.

Info

See the Spreewald README for more cool features.

You can use it to test links that were opened with a link_to(..., :target => '_blank') link or other ways that create new tabs or windows.

Important

This only works with Selenium ...

Riding Rails: Rails 4.0: Final version released!

Rails 4.0 is finally ready after a thorough process of betas and release candidates. It's an amazing new version packed with new goodies and farewells to old features past their expiration date.

Upgrading Rails 2 from 2.3.8 through 2.3.18 to Rails LTS

This card shows how to upgrade a Rails 2 application from Rails 2.3.8 through every single patch level up to 2.3.18, and then, hopefully, Rails LTS.

2.3.8 to 2.3.9

This release has many minor changes and fixes to prepare your application for Rails 3.

Step-by-step upgrade instructions:

  1. Upgrade rails gem
  2. Change your environment.rb so it says RAILS_GEM_VERSION = '2.3.9'
  3. Change your ...

Before you make a merge request: Checklist for common mistakes

Merge requests are often rejected for similar reasons.

To avoid this, before you send a merge request, please confirm that your code ...

marcandre/backports ยท GitHub

Essential backports that enable many of the nice features of Ruby 1.8.7 up to 2.0.0 for earlier versions.

How to clear cookies in Capybara tests (both Selenium and Rack::Test)

Capybara drivers will usually delete all cookies after each scenario. If you need to lose cookie data in the middle of a scenario, you can do this:

browser = Capybara.current_session.driver.browser
if browser.respond_to?(:clear_cookies)
  # Rack::MockSession
  browser.clear_cookies
elsif browser.respond_to?(:manage) and browser.manage.respond_to?(:delete_all_cookies)
  # Selenium::WebDriver
  browser.manage.delete_all_cookies
else
  raise "Don't know how to clear cookies. Weird driver?"
end