Bdd state-of-the-union (Devoxx and XPDays version)

Behavior-Driven Development on the JVM
A State of the Union

John
Ferguson
Smart

Consulta
nt
Trainer
Mentor
Author
Speaker
Coder
John Fer
guson S
mar t

Business Analyst

Common
Language
Business Developer

Tester

So why use BDD?
Only build features that add real value
Less wasted eﬀort
Better communication
Higher quality, better tested product
Traceability

BDD - Requirements Analysis and
Communication

Goals

Capabilities

Features

Stories

Examples/Scenarios

Acceptance Criteria

11

Successful projects start with a shared vision

“We are going to build an online classiﬁeds website”

12

You define goals to achieve your vision

“We can increase
advertising revenue by
letting sellers post their
classified ads online”

“Let’s get more sales for our advertisers by
making the ads easier to find online.”

Determining the value of a goal

A good goal should add value to the business
Increase revenue
Reduce costs
Avoid future costs
Protect revenue

“Increase advertising revenue by allowing
sellers to post classiﬁed ads online”

“Reduce the costs involved in publishing a classiﬁed ad
by allowing sellers to post them online themselves. ”
“Prevent current customers switching to a competing product
by providing support for online credit card payments”

What does the customer really need?

I want users to be able to search for products by keyword
Why?
So that potential buyers can ﬁnd the articles they want

Why?
So that our sellers can sell their stuff faster
Why?
So that they keep selling their stuff on our site
Why?

So that we keep earning money when they post their ads with us

What does the customer really need?

Good teams push back!
Users tend to express requirements as implementations
We need to find the business need behind the suggested
implementation

I want users to be able to search by keyword

So in order to make the site more attractive for sellers
Buyers need to be able to find things easily

A search feature might be one way to achieve this

But full-text searches might be more effective than keywords

Features and capabilities help deliver these goals

“Let’s get more sales for our advertisers by
making the ads easier to ﬁnd online.”

Notify potential buyers about new items
In Search for online of advertised articles
order to increase sales ads
As aorder to increase sales of advertised articles
In seller
I want previous buyers to know about new items
As a seller
that theybuyers be interested in buying ads for
I want might to be able to easily find
articles they want to buy

Feature Injection - what features do you do first?

Our goals say what business value we need to deliver
We implement the minimum features required to
deliver this business value
Search for online ads The goal comes first
In order to increase sales of advertised articles
The stakeholder is
As a seller secondary
I want buyers to be able to easily find ads for
articles they want to buy
The feature must be
required to achieve the goal

18

We use examples and stories to explore the features

Search for online ads

“Searching by category”

“Searching by keyword and category”

19

We use examples and stories to explore the features

Search for online ads

Searching by keyword and location
Given
Sally
wants
to
buy
a
puppy
for
her
son

When
she
looks
for
‘puppy’
in
the
‘Pets
and
Animals’
category
Then
she
should
obtain
a
list
of
ads
for
puppies
for
sale.

20

Examples and scenarios become acceptance criteria

Searching by keyword and location
Given
Sally
wants
to
buy
a
puppy
for
her
son

When
she
looks
for
‘puppy’
in
the
‘Pets
and
Animals’
category
Then
she
should
obtain
a
list
of
ads
for
puppies
for
sale.

Scenario: Searching by keyword and location

Given Sally wants to buy a present for her son
When she looks for the present in a given category
Then she should obtain a list of matching ads for sale.

Examples:
Present Category Expected Keywords
puppy Pets & Animals labrador
kitten Pets & Animals burmese
kitten Toys ﬂuffy cat

Acceptance Criteria illustrate and validate the stories

Requirements can come from many sources...

Goal:
In order to increase revenue from commissions on classified ads sales
As the head of the classified ads department
I want to increase the number of items sold via our classified ads

Capability
In order to increase the number of items I sell Feature

As a seller In order to increase sales of advertised articles

I want buyers to be able to view ads for items As a seller

they might want to purchase I want potential buyers to be able to display only the ads for
articles that they might be interested in purchasing.

Story
In order to find the items I am interested in faster
Keep them organized! As a buyer
I want to be able to list all the ads with a particular keyword in
the description or title.

25

BDD - Test Automation and Beyond

26

The original Java BDD framework

27

search_by_keyword_and_location.story
Narrative:
As a seller
I want buyers to be able to easily find ads for articles they want
to buy


Given Sally wants to buy a puppy for her son
When she looks for 'puppy' in the 'Pets and Animals' category
Then she should obtain a list of ads for puppies for sale.

29

Scenario: Searching by keyword and location 1

30

Then she should obtain a list of puppy ads
public class SearchAdsSteps {
    @Steps
2
    BuyerSteps buyer;

    @Given("Sally wants to buy a $present for her son")
    public void buyingAPresent(String present) {
        buyer.opens_home_page();
    }

    @When("she looks for $keyword in the $category category")
    public void adSearchByCategoryAndKeyword(String category, String keyword) {
        buyer.chooses_category_and_keywords(category, keyword);
        buyer.performs_search();
    }

    @Then("she should obtain a list of $keyword ads")
    public void shouldOnlySeeAdsContainingKeyword(String keyword) {
        buyer.should_only_see_results_with_titles_containing(keyword);
    }
}

31

    @Steps
2
    BuyerSteps buyer;

public class BuyerStories extends JUnitStories {
    public BuyerStories() {
3
        configuredEmbedder().embedderControls().doGenerateViewAfterStories(true).doIgnoreFailureInStories(false)
                .doIgnoreFailureInView(true).doVerboseFailures(true).useThreads(2).useStoryTimeoutInSecs(60);
    }
    }
    @Override
    @When("she looks for $keyword { the $category category")
    public Configuration configuration() in
        return new MostUsefulConfiguration();
    }
    @Override
    }
    public InjectableStepsFactory stepsFactory() {
        return new InstanceStepsFactory(configuration(), new TraderSteps(new TradingService()), new AndSteps());
    }
    @Override
    protected List<String> storyPaths() {
        String codeLocation = codeLocationFromClass(this.getClass()).getFile();
    }
        return new StoryFinder().findPaths(codeLocation, asList("**/*.story",
}                 "**/traders_can_be_subset.story"), asList(""), "file:" + codeLocation);
    }
}

32

    @Steps
2
    BuyerSteps buyer;

    }

    @When("she looks for $keyword in the $category category")
    }

    }

3’
}
public class BuyerStories extends ThucydidesJUnitStories {
}

33

Now available in JVM flavor!

34

Feature: 1
As a seller
I want buyers to be able to easily find ads for articles they want
to buy


Given Sally wants to buy a "puppy" for her son
When she looks for "puppy" in the "Pets and Animals" category
Then she should obtain a list of "puppy" ads

36

import org.junit.runner.RunWith; 2
import cucumber.junit.Cucumber;

@RunWith(Cucumber.class)
@Cucumber.Options(format={"pretty", "html:target/cucumber"})
public class RunTests {
}

37

import org.junit.runner.RunWith; 2
import cucumber.junit.Cucumber;
    @Steps
@RunWith(Cucumber.class)
3
    BuyerSteps buyer;
@Cucumber.Options(format={"pretty", "html:target/cucumber"})
public class RunTests { buy a "([^"]*)" for her son$")
    @Given("^Sally wants to
}     public void buyingAPresent(String present) {
    }

    @When("^she looks for "([^"]*)" in the "([^"]*)" category$")
    }

    @Then("^she should obtain a list of "([^"]*)" ads$")
    }
}

39

scenario "Searching by keyword and location", {
given "Sally wants to buy a puppy for her son"
when "she looks for 'puppy' in the 'Pets and Animals' category"
then "she should obtain a list of ads for puppies for sale"
}

given "Sally wants to buy a #present for her son"
when "she looks for '#present' in the '#category' category"
then "she should obtain a list of ads for #expected for sale"
where "examples should be", {
present = ['puppy', 'kitten', 'seiko']
category = ['Pets & Animals','Pets & Animals', 'Jewellery & Watches']
expected = ['puppies', 'kittens', 'watch']
}
}

40

scenario "Searching by keyword and location", { 1
}

41

scenario "Searching by keyword and location", { 1
}

using "thucydides" 2
thucydides.uses_steps_from BuyerSteps

given "Sally wants to buy a puppy for her son", {
buyer.opens_home_page()
}
when "she looks for 'puppy' in the 'Pets and Animals' category", {
}
then "she should obtain a list of ads for puppies for sale",{
buyer.should_only_see_results_with_titles_containing keyword
}
}

42

Keeping an eye on things

44

1 Discover your acceptance criteria

2 Automate your acceptance criteria

3 Implement your acceptance criteria

4 Execute your acceptance tests

45


Feature: Browse Catalog
In order to find items that I would like to buy
As a customer
I want to be able to browse through the catalog

Story: Browse by category
In order to find items more easily
As a customer
I want to be able to browse through the product categories
Acceptance Criteria
See all the top-level categories
Browse through the category hierarchy
Should display the correct products for each category
Each category should have the correct sub-categories

Deﬁne acceptance criteria for each story

46


Acceptance Criteria
See all the top-level categories
Browse through the category hierarchy

Scenario: See all top-level categories
Given I want to browse the catalog
When I am on the home page
Then I should see the following product categories: Clothing, Accessories, Shoes

Clarify the acceptance criteria with examples

48


Story: Browse by category
Acceptance Criteria
As a customer top-level categories
See all the
I want Browse through the category the product categories
to be able to browse through hierarchy
Narrative:
As a customer
I want to be able to see what product categories exist


We now have an executable requirement

49


...but they will be reported as ‘pending’

50


Narrative:
As a customer
I want to be able to see what product categories exist


51


52


JUnit

53

4 Execute your acceptance tests

From Acceptance Tests
to Developer Tests

Make it pass

Write a failing test TDD

Refactor

What test should I write?

Acceptance Tests
(high level features)

Spock

Developer Tests
(low level features)

What features should I implement?
etc.

Goal: In order to increase revenue from commissions on classified ads sales
As the head of the classified ads department
I want to increase the number of items sold via our classified ads

Story: In order to find the items I am interested in faster
Acceptance

As a buyer
I want to be able to list all the ads with a particular keyword in the description or title. Tests

Scenario: Searching by keyword
Given Sally wants to buy a apuppyfor her son
Given Sally wants to buy apuppy for her son
Given Sally wants to buy puppy for her son
When she looks for ads ininthePets & Animals category containing puppy
When she looks for ads inthe Pets & Animals category containing puppy
When she looks for ads the Pets & Animals category containing puppy
inThen she should obtain a list of ads for puppies for sale
inNew South Wales
New South Wales

class WhenCalculatingGST extends Specification {
    def "GST should apply on ordinary articles"() {
        given: should apply on ordinary articles"() { {
    def "GST "we are selling a shirt"
        given: should apply on ordinary articles"()
    def "GST "we are selling a shirt"

Developer

            def sale = Sale.of(1,"shirt").forANetPriceOf(10.00)
            def sale areSale.of(1,"shirt").forANetPriceOf(10.00)
        given: "we = selling a shirt"
        when: "we calculate the price including GST"
            def "we calculate sale.totalPrice
        when: totalPrice = the price including GST"
            def "we calculate the price GST of
        when: totalPrice including GST"
        then: "the totalPrice= =sale.totalPrice 10%"
            def price should sale.totalPrice
include
            totalPrice == should include GST of 10%"
        then: "the price 11.00 include GST of 10%"
        then: "the price should
            totalPrice == 11.00
Tests
    }
            totalPrice == 11.00
}     }
}     }
}

Spock

        given: "we are selling a shirt"
            def totalPrice = sale.totalPrice
        then: "the price should include GST of 10%"
            totalPrice == 11.00
    }
}

Given-When-Then structure

Spock

    ...

    def "GST should not apply on GST-exempt articles"() {
        given: "we are selling a bottle of milk"
        then: "the price should not include GST%"
            totalPrice == 5.00
    }
}

Meaningful error messages

Spock
Lightweight stubbing

        given: "GST is at 12.5%"
            def gstRateProvider = Mock(GSTRateProvider)
            gstRateProvider.getRate() >> 0.125
            Sales sales = new Sales(gstRateProvider)
        and: "we are selling a shirt"
            def sale = sales.makeSaleOf(1,"shirt").forANetPriceOf(10.00)
        then: "the price should include GST of 12.5%"
            totalPrice == 11.25
    }
}

Spock

class WhenDeliveringSoldItems extends Specification {

    def gstRateProvider = Mock(GSTRateProvider)
    def deliveryService = Mock(DeliveryService)

    def "Sold articles should be delivered"() {
        given: "we are selling shirts online"
            Sales sales = new Sales(gstRateProvider, deliveryService)
        when: "we sell a shirt"
            sales.makeSaleOf(1,"shirt").forANetPriceOf(10.00)
        then: "the shirt should be sent to the delivery service"
            1 * deliveryService.dispatch(_)
    }
}

Lightweight mocking

Spock
class WhenDisplayingTagNamesInAReadableForm extends Specification {

    def inflection = Inflector.instance

    def "should transform singular nouns into plurals"() {

        when: "I find the plural form of a single word"
            def pluralForm = inflection.of(singleForm).inPluralForm().toString();
        then: "the plural form should be gramatically correct"
            pluralForm == expectedPluralForm
        where:
            singleForm | expectedPluralForm
            'epic' | 'epics'
            'feature' | 'features'
            'story' | 'stories'
            'stories' | 'stories'
            'octopus' | 'octopi'
            'sheep' | 'sheep'
    }
}

Data-driven tests

Spock with Arquillian
class
AccountServiceSpecification
extends
Specification
{

@Deployment

def
static
JavaArchive
"create
deployment"()
{

return
ShrinkWrap.create(JavaArchive.class)

.addClasses(AccountService.class,
Account.class,

SecureAccountService.class)

.addAsManifestResource(EmptyAsset.INSTANCE,
"beans.xml");

}

@Inject

AccountService
service

def
"transferring
between
accounts
should
result
in
account
withdrawl
and
deposit"()
{

when:

service.transfer(from,
to,
amount)

then: BDD-style integration tests

from.balance
==
fromBalance

to.balance
==
toBalance

where:

from
<<

[new
Account(100),

new
Account(10)]

to
<<

[new
Account(50),

new
Account(90)]

amount
<<

[50,

10]

fromBalance
<<

[50,

0]

toBalance
<<

[100,

100]

}
}

class
WhenCalculatingGST
extends
Specification
{
sequential

"GST
should
apply
on
ordinary
articles"
>>
{

"Given
we
are
selling
a
shirt"
>>
{

sale
=
Sale.of(1,
"shirt").forANetPriceOf(10.00)

}

"When
we
calculate
the
price
including
GST"
>>
{

totalPrice
=
sale.totalPrice

}

"Then
the
price
should
include
a
GST
of
10%"
>>
{

totalPrice
===
11.00

}

}

var
sale
=
Sale();
var
totalPrice
=
0.0
}

class
WhenCalculatingGST2
extends
Specification
with
Mockito

{
sequential

"GST
should
apply
on
ordinary
articles"
>>
{ Lightweight

"Given
we
are
selling
a
shirt"
>>
{ stubbing DSL

val
sales
=
Sales(mock[GSTProvider])

sales.gstProvider.rate
returns
12.5

sale
=
sales.makeSaleOf(1,

}

"When
we
calculate
the
price
including
GST"
>>
{

totalPrice
=
sale.totalPrice

}

"Then
the
price
should
include
a
GST
of
12.5%"
>>
{

totalPrice
===
11.25

}

}

var
sale
=
Sale();
var
totalPrice
=
0.0
}

class
WhenDeliveringSoldItems
extends
Specification
with
Mockito

{
sequential

"Sold
articles
should
be
delivered"
>>
{

"Given
we
are
selling
shirts
online"
>>
{

sales
=
Sales(mock[GSTProvider],
mock[DeliveryService])

}

"When
we
sell
a
shirt"
>>
{

sale
=
sales.makeSaleOf(1,

}

"Then
the
shirt
should
be
sent
to
the
delivery
service"
>>
{

there
was
one(sales.deliveryService).dispatch(anyString)

}

}
Lightweight

var
sale
=
Sale();
var
sales
=
Sales() mocking DSL
}

class
WhenDisplayingTagNamesInAReadableForm
extends
Specification
with
Tables
{

"The
inflector
should
transform
singular
nouns
into
plurals"
>>
{

"""

when
I
find
the
plural
form
of
a
single
word,
then
the
plural
form
should
be

gramatically
correct:

"""
>>
{

"single
form"

|
"plural
form"

|>

"epic"

!
"epics"

|

"feature"

!
"features"

| Data-driven tests,

"story"

!
"story"

| Scala-style

"stories"

!
"stories"

|

"octopus"

!
"octopi"

|

"sheep"

!
"sheep"

|
{
(singleForm,
pluralForm)
=>

Inflection.of(singleForm).inPluralForm.toString
===
pluralForm

}

}

}
}

describe( "temperature converter", function () {
    it("converts fahrenheit to celsius", function () {
        expect(Convert(50, "F").to("C")).toEqual(10);
    });
});

Simple assertion structure

    });

    it("converts celsius to fahrenheit", function () {
        expect(Convert(30, "C").to("F")).toEqual(86);
    });
});

More complex behavior

describe( "converter library", function () {
        });

        it("converts celsius to fahrenheit", function () {
            expect(Convert(30, "C").to("F")).toEqual(86);
        });
    });

    describe( "weight converter", function () {
        it("converts kilograms to pounds", function () {
            expect(Convert(100, "KG").to("LB")).toEqual(220);
        });
    });
});
Nested behaviors

Lots of matchers

it("is
defined",
function
()
{

var
name
=
"Andrew";

property defined

expect(name).toBeDefined();

})

it("is
true",
function
()
{

true or false

expect(Lib.isAWeekDay()).toBeTruthy();

});

it("is
less
than
10",
function
()
{

expect(5).toBeLessThan(10);

greater than or less than
});

it("is
greater
than
10",
function
()
{

expect(20).toBeGreaterThan(10);

});

it("should
contain
oranges",
function
()
{

expect(["apples",
"oranges",
"pears"]).toContain("oranges");

});

contains

Evaluate test results in a browser

Generate JUnit-compatible results

hAp://try-‐jasmine.heroku.com/

In conclusion...

It’s behavior all
the way down

Thank You

John
Ferguson
Smart

Bdd state-of-the-union (Devoxx and XPDays version)

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