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Automated Testing with Cucumber + Capybara

October 29, 2012 10 comments

In this post we will introduce another gem called Capybara.

Capybara is an acceptance testing framework with a higher level API and support for multiple backends, supports Selenium and runs in different browsers.

Others may ask, “Why would I use capybara if selenium could also drive the browser the way I want it?”  Well, one advantage I appreciate is Capybara’s higher-level API compared to selenium.

Let’s take for example a simple scenario of typing strings to an input textbox:

Selenium-webdriver snippet


require 'selenium-webdriver'

element = driver.find_element :name => "q"
element.send_keys "Cucumber tests"

Capybara snippet

require 'capybara'

fill_in "q", "Cucumber tests"

You can obviously see from this example that Capybara enforces easier writing scripts ability. For a complete documentation on Capybara you can check this link from Github which I found very helpful.

After installation setup discussed in my previous post Introduction to Cucumber, you need to have the following folder structure and files:

I. Base Folder

Base Folder Structure

where:

features – folder to host all your feature files

step_definitions – folder to host all your step definition Ruby files

support – folder to host your configuration files (env.rb)

Gemfile – defines the top-level gems to be used in your project

II. Features

– describes the features that a user will be able to use in the program

Sample: simple_search.feature


Feature: As a user I should be able to perform simple google search

Scenario: A simple google search scenario
 Given I am on the main google search
 When I fill in "q" with "Cucumber test"
 And I click "gbqfb" button
 And I click on the first result
 Then I should see "Cucumber lets software development teams describe how software should behave in plain text."

III. Step Definition

– describes the actions that user will do for each step.

Sample: search_step.rb

Given /^I am on the main google search$/ do
 visit ('/')
end

When /^(?:|I )fill in "([^"]*)" with "([^"]*)"$/ do |field, value|
 fill_in(field, :with => value)
end

Then /^I click "([^"]*)" button$/ do |button|
 click_button(button)
end

Then /^I click on the first result$/ do
 find(:xpath, "//html/body/div[3]/div[2]/div/div[5]/div[2]/div[2]/div/div[2]/div/ol/li/div/h3/a").click
end

Then /^I should see "([^"]*)"$/ do |text|
 page.should have_content(text)
end

IV. Support

– hosts all configuration files

Sample: env.rb

require 'capybara'
require 'capybara/cucumber'

Capybara.default_driver = :selenium
Capybara.app_host = "http://www.google.com"
Capybara.default_wait_time = 20

World(Capybara)

V. Gemfile

– a format for describing gem dependencies required to execute Ruby codes

Sample: Gemfile


source "http://rubygems.org"

group(:test) do
 gem 'cucumber'
 gem 'capybara'
 gem 'rspec'
end

VI. Run

Using terminal go to your root project folder and type: cucumber or bundle exec cucumber

After the run, you should be able to see the results like this:

1 scenario (1 passed)
5 steps (5 passed)
0m9.461s

This example runs smoothly in Windows 7. Let me know if it works for you as well.

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Introduction to Cucumber

October 29, 2012 1 comment

More than a testing tool, Cucumber is a collaboration tool.

It is designed to accommodate both the technical(developers, automation testers) and non-technical(stakeholders, product owners) members of the software development team.

Cucumber supports behavior-driven development(BDD). In BDD, users(business analysts, product owners) first write scenarios or acceptance tests that describes the behavior of the system from the customer’s perspective, for review and sign-off by the product owners before developers write their codes.

When you run your test, Cucumber reads through user-readable files called features, parse it to scenarios which contains set of steps that are then matched to a step definitions of Ruby code using a regular expression.

Feature files could be deceiving. It may look simple and plain in the outside. But complex in the inside, within step definition or the ruby files which controls the flow of actions and where all the magic happens.

In order for Cucumber to understand the feature files, it uses a basic syntax called Gherkin. Gherkin makes use of the following keywords for documentation and readability — Feature, Background, Scenario, Given, When, Then, And, But, *, Scenario Outline and Examples.

To dive more information about Cucumber, I would recommend you read The Cucumber Book  which have valuable information you would need in learning this new technology.

In preparation to  your Cucumber testing experience, will be needing to setup the following in your local machine.

1. Java installation – JRE will do, mine is Java(TM) SE Runtime Environment 1.6

2. Ruby installation – visit their Downloads page. I have Jruby 1.6.7.2 installed in my box.

Don’t forget to define Java and Ruby Path in your system’s environment variables as well.

3. RubyGems installation – use “gem install <name of gem>” command. Here are some of the basic, helpful gems:

– Cucumber

– Capybara

– Rspec

If you’re all setup, feel free to jump to the next post – Automated Testing with Cucumber + Capybara

Reference: The Cucumber Book by Matt Wynne and Aslak Hellesoy

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