Behavior driven development - cucumber, Junit and java

© 2014 Leanpitch | CONFIDENTIAL
Behavior Driven Development
Naveen Kumar Singh CSP, PMI-ACP, CSM, PMP

Agenda
User Story
TDD, ATDD, and BDD
BDD in Details
BDD in Action
Why Cucumber?

User Story

User Story
• Product: Groceries Billing System
• Stories
• As an account I want to calculate bills of groceries purchased by customer so that I
can generate invoice.
• As an account I want to update groceries rates so that bills reflect correct rate
• As an account I want to issue discount coupon so I can give to customer to redeem
next time.

Acceptance Criteria
What to check at the end of development?
Ordered Pizza online, then Pizza get delivered at home or confirmation mail
in your inbox

Acceptance Testing
Making sure the software works correctly for the intended user in his or
her normal work environment.
• Alpha test
• Version of the complete software is tested by the customer under
the supervision of the developer at the developer’s site
• Beta test
• Version of the complete software is tested by the customer at his or
her own site without the developer being present

TDD, ATDD, and BDD

ATDD BDD TDD

Acceptance/Customer Test Driven Development
Acceptance Test-Driven Development (ATDD) is a development
methodology based on communication between the business customers,
the developers, and the testers. ATDD encompasses many of the same
practices as Specification by Example, Behavior Driven Development
(BDD), Example-Driven Development (EDD), and Story Test-Driven
Development (SDD). All these process aid developers and testers in
understanding the customer’s needs prior to implementation and allow
customers to be able to converse in their own domain language.

ATDD Advantage
Close collaboration
Seeing concrete, working software
Building trust and confidence
Customer in control
Evolving a shared language
Tests as a shared language
Tests as specification
Specification by example

ATDD Test Format
Scenario: Send email
Given that a web based email module has been developed
And I am accessing it with proper authentication
When I shall write the sender email address in To field
And keeping the subject field non empty
And write something in the body text area which accepts rich text
And press or click send button
Then my email will be sent
And the event will be logged in the log file.

BDD in Details

Behaviour Driven Development (BDD)
BDD is a second-generation, outside-in, pull-based, multiple-
stakeholder, multiple-scale, high-automation, agile methodology. It
describes a cycle of interactions with well-defined outputs, resulting in
the delivery of working, tested software that matters. – Dan North

BDD
Given- Set of
preconditions
Then-Some
testable outcome
When-When a
event occurs

BDD Features
• A testable story (it should be the smallest unit that fits in an iteration)
• The title should describe an activity
• The narrative should include a role, a feature, and a benefit
• The scenario title should say what's different
• The scenario should be described in terms of Givens, Events, and
Outcomes
• The givens should define all of, and no more than, the required context
• The event should describe the feature

BDD Cycle
Add
Test
Test Fail
Code
Rerun
Test
Refactor

BDD Example
Story: Returns go to stock
In order to keep track of stock
As a store owner
I want to add items back to stock when they're returned

BDD Example
Scenario 1: Refunded items should be returned to stock
Given a customer previously bought a black sweater from me
And I currently have three black sweaters left in stock
When he returns the sweater for a refund
Then I should have four black sweaters in stock

BDD Example
Scenario 2: Replaced items should be returned to stock
Given that a customer buys a blue garment
And I have two blue garments in stock
And three black garments in stock.
When he returns the garment for a replacement in black,
Then I should have three blue garments in stock
And two black garments in stock

Tools
ATDD
FitNesse
Spectacular
Concordian
Thucydides
BDD
SpecFlow
Cucumber
JBehave
NBehave
Behat
TDD
JUnit
NUnit
TestNG
MSTest

BDD is an Agile Process
BDD encourages collaboration between developers, QA and non-technical
or business participants in a software project.

BDD in Action

BDD Classroom Exercise-GOAL
Write BDD code to calculate Groceries Bills

BDD Classroom Exercise-Feature File
#encoding: utf-8
Feature: Checkout
In order to calculate price of groceries
As a Store Staff
I should be able to calculate price for groceries during checkout
Scenario: Checkout a banana
Given The price of a “Banana” is $5
When I checkout 1 “Banana”
Then the total price should be $5

BDD Classroom Exercise-Add Test Runner Class
package test.java;
import org.junit.runner.RunWith;
import cucumber.api.CucumberOptions;
import cucumber.api.junit.Cucumber;
@RunWith(Cucumber.class)
@CucumberOptions(features = "src/test/resources")
public class testrunner
{
}

BDD Classroom Exercise-Run BDD Scenarios
1 Scenarios ([33m1 undefined[0m)
3 Steps ([33m3 undefined[0m)
0m0.000s
You can implement missing steps with the snippets below:
@Given("^The price of a "([^"]*)" is $(d+)$")
public void The_price_of_a_is_$(String arg1, int arg2) throws Throwable {
// Express the Regexp above with the code you wish you had
throw new PendingException();
}
@When("^I checkout (d+) "([^"]*)"$")
public void I_checkout(int arg1, String arg2) throws Throwable {
}
@Then("^the total price should be $(d+)$")
public void the_total_price_should_be_$(int arg1) throws Throwable {
}

BDD Classroom Exercise-Add Test Step
public class teststeps {
}
@When("^I checkout (d+) "([^"]*)"$")
}
}
}

BDD Classroom Exercise-Add Required Functionality and Test Scenarios
public class teststeps extends TestCase {
String product;
int rate, qty;
product = arg1;
rate = arg2;
}
@When("^I checkout (d+) "([^"]*)"$")
qty=arg1;
}
if(product.equals("Banana"))
assertEquals(arg1, rate*qty);
}
}

BDD Classroom Exercise-Run Scenarios Again

Why Cucumber?

Cucumber
Cucumber was originally created as a command-line tool by members of
the Ruby community. It has since been translated into several different
development environments, including Java, to allow more of us to enjoy its
benefits.
When you run Cucumber, it reads in your specifications from plain-
language text files called features, examines them for scenarios to test, and
runs the scenarios against your system.
Each scenario is a list of steps for Cucumber to work through. So that
Cucumber can understand these feature files, they must follow some basic
syntax rules. The name for this set of rules is Gherkin.

Cucumber
Along with the features, you give Cucumber a set of step definitions, which
map the business-readable language of each step into code to carry out
whatever action is being described by the step. In a mature test suite, the
step definition itself will probably just be one or two lines of code that
delegate to a library of support code, specific to the domain of your
application, that knows how to carry out common tasks on the system.
Sometimes that may involve using an automation library, like the browser
automation library Selenium, to interact with the system itself.

Cucumber
Your Project Features Scenarios Steps
Your System
Automation
Library
Support
Code
Step
Definitions
Technology
Facing
Business
Facing

Cucumber

Gherkin-Keywords
A Gherkin file is given its structure and meaning using a set of special keywords.
There’s an equivalent set of these keywords in each of the supported spoken
languages, but for now let’s take a look at the English ones:
• Feature
• Background
• Scenario
• Given
• When
• Then
• And
• But
• *
• Scenario Outline
• Examples

Gherkin- Background
Feature: Feedback when entering invalid credit card details
In user testing we've seen a lot of people who made mistakes entering their credit card. We
need to be as helpful as possible here to avoid losing users at this crucial stage of the
transaction.
Background:
Given I have chosen some items to buy
And I am about to enter my credit card details
Scenario: Credit card number too short
When I enter a card number that's only 15 digits long
And all the other details are correct
And I submit the form
Then the form should be redisplayed
And I should see a message advising me of the correct number of digits

Gherkin- Multiple AND
Scenario: Expiry date invalid
When I enter a card expiry date that's in the past
And all the other details are correct
And I submit the form
Then the form should be redisplayed
And I should see a message telling me the expiry date must be wrong

Gherkin- Replacing Given/When/Then with Bullets
Some people find Given, When, Then, And, and But a little verbose. There is an
additional keyword you can use to start a step: * (an asterisk). We could have
written the previous scenario like this:
Scenario: Attempt withdrawal using stolen card
* I have $100 in my account
* my card is invalid
* I request $50
* my card should not be returned
* I should be told to contact the bank
To Cucumber, this is exactly the same scenario. Do you find this version easier to
read? Maybe. Did some of the meaning get lost? Maybe. It’s up to you and your
team how you want to word things. The only thing that matters is that everybody
understands what’s communicated.

Gherkin- Comments
# This feature covers the account transaction and hardware-driver modules
Feature: Withdraw Cash
In order to buy beer
As an account holder
I want to withdraw cash from the ATM
# Can't figure out how to integrate with magic wand interface
Scenario: Withdraw too much from an account in credit
Given I have $50 in my account
# When I wave my magic wand
And I withdraw $100
Then I should receive $100

Gherkin- Doc Strings
Doc strings just allow you to specify a larger piece of text than you could fit on a
single line. For example, if you need to describe the precise content of an email
message, you could do it like this:
Scenario: Ban Unscrupulous Users
When I behave unscrupulously
Then I should receive an email containing:
"""
Dear Sir,
Your account privileges have been revoked due to your unscrupulous behavior.
Sincerely,
The Management
"""
And my account should be locked

Cucumber- Step Definitions
In Cucumber, results are a little more sophisticated than a simple pass or fail. A
scenario that’s been executed can end up in any of the following states:
• Failed
• Pending
• Undefined
• Skipped
• Passed
These states are designed to help indicate the progress that you make as you
develop your tests.

Failed – During execution based on Assert
Passed – During execution based on Assert
Pending – Pending exception
Undefined – Steps are missing in step file
Skipped – All pending and undefined

Element Purpose Default
dryRun true (Skip execution of glue code) False
strict true (will fail execution if there are undefined or
pending steps)
False
glue where to look for glue code (stepdefs and hooks) {}
features the paths to the feature(s) False
monochrome whether or not to use monochrome output False
format what formatter(s) to use {}
tags hat tags in the features should be executed {}

@CucumberOptions(
dryRun = false,
strict = true,
features = "src/test/features/com/sample",
glue = "com.sample",
tags = { "~@wip", "@executeThis" },
monochrome = true,
format = {"pretty", "html:target/cucumber",
"json:target_json/cucumber.json",
"junit:taget_junit/cucumber.xml“ }
)

dryRun: if dryRun option is set to true then cucumber only checks if all the steps
have their corresponding step definitions defined or not. The code mentioned in
the Step definitions is not executed. This is used just to validate if we have defined
a step definition for each step or not.
Strict: if strict option is set to false then at execution time if cucumber encounters
any undefined/pending steps then cucumber does not fail the execution and
undefined steps are skipped and BUILD is SUCCESSFUL.
Monochrome: if monochrome option is set to False, then the console output is
not as readable as it should be. may be the output images will make this more
clear.

Cucumber- Regular Expression
Step definitions use regular expressions to declare the steps that they can
handle. Because regular expressions can contain wildcards, one step
definition can handle several different steps.

Our Upcoming CSD Training – Please check Scrum Alliance
Please Reach out to US
scrum@leanpitch.com
+91 9902377677

Naveen Kumar Singh
Naveen.singh@Leanpitch.com
Agile Coach
http://in.linkedin.com/in/naveenkumarsingh1
Twitter - @naveenhome

Behavior driven development - cucumber, Junit and java

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