What’s Capybara
Capybara is a webrat alternative which aims to support all browser simulators.
As you know, webrat can not run javascript on the webpage. In order to test javascript and AJAX based website we need install Selenium-client github .com/ph7/selenium-client and learn extra API and also some configuratons.
Capybara
give your a full stack solution.
You can use similar
API
drive webrat and selenium. And don’t need worry about configuraton.
What’s more, Capybara integrated Celerity which is a JRuby wrapper around HtmlUnit - a headless Java browser with JavaScript support. As your expect it using the same API.
And the killer feature of Capybara is you can easily change driver it use for testing. Not only in config file but also in runtime.
Why we need Cucumber
Before I introduce what is Cucumber, you need know what is BDD .
BDD is an evolution thinking behind TestDrivenDevelopment and AcceptanceTestDrivenPlanning
You don’t need worry about what the hell BDD is. After you start using Cucumber you will know. I promise.
Cucumber
is allow you execute plain-text which written by
BDD
like format as automated tests.
There are plenty of materials on the internet which you can learn Cucumber
First place your need go is Ryan Bates’ RailsCasts
Beginning with Cucumber
Then
official Wiki of Cucumber
will very helpful!!, and there also list some
blog posts
written by community
I won’t involve more about it. In my later blog post I will give you some tricks about using Cucumber.
Using Cucumber and Capybara
Install
Follow the instruction on Capybara:
Install as a gem
sudo gem install capybara
On
OSX
you may have to install libffi, you can install it via MacPorts with:
sudo port install libffi
And you also need install Cucumber
sudo gem install cucumber
Generate basic Cucumber folder structure and configuratons
Capybara is built to work nicely with Cucumber. You can easily generate Capybara style cucumber structure and configuraton.
script/generate cucumber --capybara
And maybe you also need install another gem named
launchy
which is helper class for launching cross-platform applications in a fire and forget manner.
sudo gem install launchy
group :cucumber
do
gem
'
capybara
'
gem
'
database_cleaner
'
gem
'
cucumber-rails
'
gem
'
cucumber
'
gem
'
rspec-rails
'
gem
'
spork
'
gem
'
launchy
'
# So you can
do
Then show me the page
end
Configuration
Available Configuration
Actually after you run the generator, you don’t need much more configuraton. Here I’ll list some of configuraton you can set.
You can specify it in
features/support/env.rb
file
Capybara.run_server =
true
#Whether start server when testing
Capybara.default_selector
= :xpath #
default
selector , you can change to :css
Capybara.default_wait_time
=
2
#When we testing AJAX, we can
set
a
default
wait time
Capybara.ignore_hidden_elements
=
false
#Ignore hidden elements when testing, make helpful when you hide or show elements
using
javascript
Capybara.javascript_driver
= :culerity #
default
driver when you
using
@javascript tag
Load rails test features
You can put codes below in
features/support/env.rb
file
Before
do
Fixtures.reset_cache
fixtures_folder
= File.join(RAILS_ROOT,
'
test
'
,
'
fixtures
'
)
fixtures
= Dir[File.join(fixtures_folder,
'
*.yml
'
)].map {|f| File.basename(f,
'
.yml
'
) }
Fixtures.create_fixtures(fixtures_folder, fixtures)
end
And change
Cucumber::Rails::World.use_transactional_fixtures =
false
DatabaseCleaner.strategy
= :truncation
OK. For now we already finish configuration. we can start writing cucumber test
How to run test under different testing driver
As you know cucumber support
tags
Capybara using tag to specify different driver, it supports
@javascript, @selenium, @celerity, @culerity and @rack_test
tags
You can use it like:
@javascript
Scenario:
do
something AJAXy
When I click the AJAX link
...
About how to write cucumber, you can check out Cucumber Wiki
About Capybara API
What I want to show you is how’s Capybara API look like.
This is all support Webrat like API s in Capybara
DSL_METHODS =
[
:all, :attach_file, :body, :check, :choose, :click, :click_button, :click_link, :current_url, :drag, :evaluate_script,
:field_labeled, :fill_in, :find, :find_button, :find_by_id, :find_field, :find_link, :has_content
?, :has_css?
,
:has_no_content
?, :has_no_css?, :has_no_xpath?, :has_xpath?, :locate, :save_and_open_page, :
select
, :source, :uncheck,
:visit, :wait_until, :within, :within_fieldset, :within_table, :has_link
?, :has_no_link?, :has_button?, :has_no_button?
,
:has_field
?, :has_no_field?, :has_checked_field?, :has_unchecked_field?, :has_no_table?, :has_table?
, :unselect,
:has_select
?, :has_no_select?
]
Here are some examples which are not mentioned in Capybara Wiki.
# we can
get
page
object
from
cucumber steps, page
is
an instance of @Capybara::Session@
page.has_css
?
"
ul.error_messages li
"
, :count =>
5
, :text =>
"
error
"
page.has_xpath
?
"
//ul[@class='error_messages']/li
"
, :count =>
5
, :text =>
"
error
"
#Equivalent
page.find(:css,
"
ul.error_messages li
"
, :count =>
5
, :text =>
"
error
"
page.find(:xpath,
"
//ul[@class='error_messages']/li
"
, :count =>
5
, :text =>
"
error
"
#Iterate all elements you found
all(:xpath,
"
//ul[@class='error_messages']/input
"
).each
do
|node|
puts node.value
puts node.[:attribute_name]
puts node.click
puts node.
set
(
"
aa
"
) #
set
value
puts node.text
end
XPath
If you want to use XPath in Capybara, you need caution string escape.
Capybara give us a good example
def s(
string
)
if
string
.include?(
"
'
"
)
string
=
string
.split(
"
'
"
, -
1
).map
do
|substr|
"
'#{substr}'
"
end.join(
%q{,
"
'
"
,})
"
concat(#{string})
"
else
"
'#{string}'
"
end
end
Summarize
Cucumber + Capybara will make your integration test easilier.
Finally we find a full stack integration test.
Have fun with it!
from : http://www.allenwei.cn/cucumber-capybara-what-we-need-for-rails-integration-test
Cucumber + Capybara - What we need for rails integration test
