Behavior Driven Development

With Cucumber and GherkinBy – Arati Joshi

Audience

• Product Owners• Business Owners• Subject Matter Experts• Business Analysts• Testers• Developers

What is Cucumber?• Cucumber is framework designed specifically to help business

stakeholders get involved in writing acceptance tests.• It allows acceptance tests to be automated and the

acceptance tests to be “executed” against the system.• It helps “bridging the communication gap between domain

experts and developers”.• Each test case in Cucumber is called a scenario, and scenarios

are grouped into features.• Each scenario contains several steps.• Under the hood, step definitions translate from the business-

facing language(Gherkin) into Java code

What is an Acceptance Test?

• Validates that the ‘right’ system is being built• Business/user/customer point of view• Written in non-technical format• Helps document what the system should do• When automated, become “living

documentation”• Shared team understanding of what’s being built• Helps define what “done” means

What is Gherkin?

The business-facing parts of a Cucumber test suite, stored in feature files, must be written according to syntax rules—known as Gherkin—so that Cucumber can read them.Gherkin is –• Business readable domain specific language• Represents tests in natural language, not code• Line-oriented• Keywords(e.g. Feature, Scenario)• Localized in 40+ spoken languages (French, Bulgarian,

Japanese etc.)

What we are going to discuss about?

• Feature• Scenario• Given, When, Then, And, But keywords• Tags• Comments• Data Tables• Scenario Outline• Background• pyStrings

Feature

• Start with “Feature: “ keyword• Followed by feature name/terse description• Optional free text description

Feature: Activate CAD/BOM Alignment functionalityIn order to view the side by side report from the WizardAs a valid AVBOM2 application userI want an ability to set CAD BOM Effective Points for the AVBOM2 program in

the AVBOM2 application

Feature

In order to <meet some goal> As a <type of stakeholder> I want <a feature>

Example :-

Feature: View side by side reportIn order to view side by side report from WizardAs a valid AVBOM2 application userI want an ability to set CAD BOM Effective point for AVBOM2 program in

AVBOM2 application

Value centric

Feature

As a <type of stakeholder> I want <a feature> So that <some goal can be met>

Example :-

Feature: View side by side reportAs a valid AVBOM2 application userI want an ability to set CAD BOM Effective point for AVBOM2 program in

AVBOM2 applicationSo that I can view side by side report from Wizard

Role/person centric

Scenario

• Concrete examples of expected system behavior• Describes a particular situation• Should be independent and isolated• Can represent:– Happy paths– Error paths

• Start with “Scenario: “ keyword• Followed by title• Keep your scenarios short, and don’t have too many,

i.e., less than ???

Scenario Steps

Given When Then

Set up initial state Perform action(s) Check end state

GivenPurpose - To put the system in a known state before the user (or external system) starts interacting with the system (in the When steps).Givens are like preconditions in use cases.

Good practice – Avoid talking about user interaction in givens.

Example -

@FormValidationScenario: Check if valid program is selected for CAD BOM effective point selection

Given user is on the 'Activate CAD BOM Alignment screen' When program is not selectedAnd the 'Save' button is clickedThen screen should show an error stating """Please select program first for effective point selection. """

WhenPurpose - To describe the key action that the user performs.

Example -

@FormValidationScenario: Check if valid program is selected for CAD BOM effective point selection

Given user is on the 'Activate CAD BOM Alignment screen' When program is not selectedAnd the 'Save' button is clickedThen screen should show an error stating """Please select program first for effective point selection. """

ThenPurpose - To observe outcomes

Good Practice - The observation should be related to business value/benefit in your feature description. The observations should inspect output of the system(a report, user interface, message, command output) and not something which has no business value and instead part of implementation.Example -@FormValidationScenario: Check if valid program is selected for CAD BOM effective point selection

Given user is on the 'Activate CAD BOM Alignment screen' When program is not selectedAnd the 'Save' button is clickedThen screen should show an error stating """Please select program first for effective point selection. """

And, ButPurpose - If you have several 'Given', 'When' or 'Then' steps then 'And' or 'But' could be used to read scenario more frequently.

Example -@FormValidationScenario: Check if valid program is selected for CAD BOM effective point selection

Given user is on the 'Activate CAD BOM Alignment screen' When program is not selectedAnd the 'Save' button is clickedThen screen should show an error stating """

Please select program first for effective point selection. ""“

@AccessCheckScenario: Role check for user to be able to set the CAD BOM effective point for a program

Given role of the user is BOM AdminThen user has 'Edit' access to 'Activate CAD BOM Alignment Screen'But for all other roles user having 'Read Only' access to 'Activate CAD BOM Alignment Screen'

Tags• Mark features and scenarios with arbitrary tags• Map to unit test framework “categories”• Scenarios “inherit” feature tags• Can have multiple tags• Tags specified using @• @ignore is a special case

@AccessCheckScenario: Role check for user to be able to set the CAD BOM effective point for a program

Given role of the user is BOM AdminThen user has 'Edit' access to 'Activate CAD BOM Alignment Screen'But for all other roles user having 'Read Only' access to

‘Activate CAD BOM Alignment Screen'

Tags

• Possible uses:– Group features into feature supersets– Mark certain tests as @important– Differentiate between @slow and @fast executing

tests– Mark tests @wip– Mark tests to be executed @weekly @daily

@hourly– Mark tests as @humanexecuted

Comments

• Keywords in Cucumber can be preceded with comments

• Comments allows user to provide details about the ‘Feature’ or ‘Scenario’

Multiline Arguments - Data Tables@Scenario: User logging in into AVBOM2 application is a valid AVBOM2 user

Given user has one of the roles given below|UserRole ||D & R Engineer ||BOM Admin ||CAD Designer ||External Supplier |

Then user is a valid internal or external Ford Motor company user

Multiline Arguments - pyStrings• Multiline Strings (also known as pyStrings) are handy for specifying larger piece of

text.• Text should be offset by delimiters consisting of three double quote marks(“””) on

lines by themselves.

Example -@FormValidationScenario: Check if valid program is selected for CAD BOM effective point selection

Given user is on the 'Activate CAD BOM Alignment screen' When program is not selectedAnd the 'Save' button is clickedThen screen should show an error stating """Please select program first for effective point selection.

“””

Scenario Outline@AccessCheckScenario Outline: User authorization to view 'Activate CAD BOM Alignment' link

Given user is valid internal or external Ford Motor Company user And user has logged in to <Application Type> And user has <User Role> role Then user is able to view 'Activate CAD BOM Alignment' link

Examples:|Application Type |User Role ||AVBOM2 dashboard|Any ||AVBOM2 portal |BOM Admin |

Background• Provides context(state setup) to the scenarios in a feature• Execute before every scenario• Don’t use Background to set up complicated state unless that state is something the

reader actually needs to know. • Background section short. After all, you’re expecting the user to actually remember

this stuff when reading your scenarios.

Example:Background: User logging in into AVBOM2 application is valid AVBOM2 user

Given user has one of the roles given below|UserRole ||D & R Engineer ||BOM Admin ||CAD Designer ||External Supplier |Then user is valid internal or external Ford Motor company user

Summary

We learned about Gherkin language syntax:-• Feature• Scenario• Given, When, Then, And, But keywords• Tags• Comments• Data Tables• pyStrings• Scenario Outline• Background