Transcript - ISQT International

Agile BDD using RSpec and Cucumber
Aruna Banavar Shankar & Miti Bhat
© 2012. Infosys Limited. Strictly private and confidential. No part of this document should be reproduced or distributed
Infosys Confidential © 2012
without the prior permission of Infosys Technologies Limited.
Contents
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BDD
Installation
Demo for Rspec
Demo for Cucumber
The Basic Features
Cucumber vs. Rspec
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A story
An elephant as seen by 6
blind people!
The elephant was
assumed to be what was
“felt” by these blind
people
One question! – Can everyone see one entity as it is???
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Introduction to BDD
• “Getting the Words Right” is the focus of BDD, leading to building one
language that is understood the same way by the project stakeholders
• Vision is to bring in consistency, accuracy and meaning
• Behavior Driven Development (BDD) claims “the words you use about
something influence the way you think about that”.
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How it works?
• As <a ROLE> I need a <FEATURE> towards <BENEFIT>
• Examples
• As an <ADMIN> I need <ACCESS TO FUNCTIONAL ADMIN PORTAL>
to <MANAGE USERS>
• As the <IT MANAGER> I need <DETAILED REPORT> to <VALIDATE IT
SPEND>
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Key stakeholders in a project
Developer –
- Interested in coding than testing
- If tester finds a defect or if time permits …… focus on defects
- Let me code first is the general tendency
Tester –
- Primary responsibility is to test and find defects
Customer –
- Clarifications, approvals, sign off
Different stakeholders, unlike mindset, varied mission come together in the project.
Building an application by understanding its behavior from all stakeholder point of view.
This builds a collaboration between developer, Tester, business and
other teams.
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Then……what is BDD
In the "Agile specifications, BDD and Testing eXchange" in November 2009 in
London, Dan North[3] gave the following description of BDD:
BDD is a second-generation, outside–in, pull-based, multiple-stakeholder, multiplescale, high-automation, agile methodology. It describes a cycle of interactions with
well-defined outputs, resulting in the delivery of working, tested software that
matters.
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About them…
• RSpec created by Steven Baker in 2005.
• To explore new TDD frameworks
• Encourage focus on behavior…. Rspec
• 2008, Aslak Hellesøy
• To explore new BDD frameworks
• Rewrites RSpec’s Story Runner with a real grammar… Cucumber
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Installation
• Installed as gems:
• rspec
• cucumber
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Folder Structure
http://www.sharpthoughts.org
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Cucumber & RSpec
Ref: The Rspec Book by David Chelimsky and others
published by The Pragmatic Bookshelf
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Demo Hello Rspec
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Demo: Hello Cucumber
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Step Definitions
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Creates a step.
Methods:
Given( )
When( )
Then( )
• Each must have
• Regexp
• A block.
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Step definitions Sample
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Given /^a greeter$/ do
@greeter = CucumberGreeter.new
end
When /^I send it the greet message$/ do
@message = @greeter.greet
end
Then /^I should see "([^"]*)"$/ do |greeting|
@message.should == greeting
end
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Demo: step Definitions
website2
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User stories
• Consider:
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User navigates to home page
User enters details
User successfully logs in
User unsuccessful in logging in
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DEMO: Multiple scenarios
Website: adding more scenarios without tables
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Scenario outlines
• Let us define a single scenario outline
• Tables of input data
• Expected output.
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Sample: Scenario outlines
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Scenario Outline: submit guess
Given the secret code is "<code>"
When I guess "<guess>"
Then the symbol should be "<symbol>"
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Sample: scenario Outlines
• Scenario Outline: submit details
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Given the user name is "<uname>"
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When I guess "<pwd>"
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Then the message should be "<mesg>"
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Scenarios: no matches
| uname | pwd | symbol|
| ^^^^ | a1a1 | failed |
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Scenarios: 1 uname incorrect
| uname | pwd | mesg |
| abcd | 1555 | passed |
| ba-mn| 2555 | failed |
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Test doubles
• An object that behaves as though it is the original object
• Eg: output
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Demo:Test Double
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Uses test double but shows logical error
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“It” method
• The it( ) method:
• creates an example
• ExampleGroup returns an instance of it using describe( )
Demo: website5 Note: Rspec double(out) – a mock for STDOUT
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A small change
• def start
• @output.puts 'Welcome to website!'
• end
• The test passes!!!
• Once the passing code is ready… See it in action!!!
• Demo: website6 using .bat file
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When Cucumber & WHEN Rspec
• Cucumber - integration/acceptance testing
• rspec/test unit - Model unit tests.
1)
2)
3)
4)
Define feature scenario in cucumber
Start by implementing every step of feature scenario
For each functionality required BDD that with rspec
Repeat until functionality is complete
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Hooks
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Hooks:
• Before - every scenario
• After - every scenario
• AfterStep - after every step
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Backgrounds
• Steps that are invoked
• Before and After every scenario
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Feature: browse books
Background: Logged in
Given I have logged in as “Aruna"
And the following models exist:
| manufacturer | carmodel? |
| Ford | yes |
| Honda| no |
Scenario: Display a car that already exists
Scenario: Display a car that is not yet in market
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Configuration
• Command Line configuration for:
• Switches
• Options
•Eg:
•mycmd: --tags @wip features
•Usage:
•cucumber –p mycmd
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References / Bibliography
• The Rspec Book by David Chelimsky and others published by The
Pragmatic Bookshelf
• http://www.infoq.com
• Wikipedia
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