EXECUTABLE REQUIREMENTSGodfrey Nolan

RIIS LLC

GANG 10 Year Celebration

10/1/11

RIIS• IT Consultants and Developers since ‘98

• Based in Southfield, MI• Contact godfrey@riis.com

• Skills• Requirements, Development, Testing• iOS/Android, Java/C#, Oracle/SQL Server

• Clients• Fandango, Comerica, Cengage, Broadsoft, DTE, BondDesk,

Proctor Financial, Blue Cross, TK, Hanson

• Godfrey Nolan• godfrey@riis.com• 10 years ago – Unraveling the .Net executable

Agenda

What Makes a Good Requirement?• Unique – address one thing only• Complete – no missing information• Consistent – doesn’t contradict other req.• Traceable back to business need• Current – not obsolete• Feasible – can be implemented• Unambiguous – objective not subjective• Mandatory – not a nice to have• Verifiable – testable

What makes a Bad Requirement?• Lengthy• Unfocused• Ambiguous• Verified Manually

Attempts at Fixing the Problem• Company Wide Templates• Use Cases or User Stories• Requirement Reviews• Traceability Matrix• Requirements Metrics• Visualization/Simulation – iRise, Axure, Balsamiq• Agile Development – TDD, Scrum, Kanban• ALM, CLM

Use Case

Scope: ATM

Level: User Goal

1. The card gets inserted.

2. The card information gets validated.

3. The transaction information gets collected and validated.

4. The cash is issued, card returned, cash removed, account debited, screen reset.

User Story

1. User checks balance

2. User logs into the machine

3. User get "Fast Cash"

4. User makes a deposit

5. User withdraws from checking

6. User withdraws from savings

Traceability Matrix

Visualization

But inevitably…

• Some or all the following happen• Scope change• Requirements confusion• Developer interprets the requirement• Business stakeholder doesn’t get what they’re expecting• Completely missed some crucial requirement• Requirements never kept up to date

But What if?

Imagine a world where developers get detailed requirements in a format and mechanism that is readable by the business facing people...

...completely devoid of ambiguity in terms of what the correct behavior is...

...and can also be used as an automated test within your team's continuous integration processes. (Tim Wingfield)

But What If? (TechTalk)

But What If?

TDD

Executable Requirements

Executable Requirements• These were the Droids you were looking for..

• BDD or Behavior Driven Design• Functional Tests• Integration Tests• Acceptance Tests• ATDD or Acceptance Test Driven Design• Specification by Example• Outside in Development• Executable Requirements

Outside In Development

Manual Testing (Matt Stine)

Testing Pyramid (Lisa Crispin)

Continuous Integration

Continuous Integration• Automated Build Process• Code gets checked in• Unit tests run• Executable tests run• Code gets deployed only if everything passes• Requirements are kept up to date!

Writing Executable Requirements• Features file

• Written in DSL called Gherkin• Feature description• Scenario Outline

• Given/When/Then

• Examples (optional)• Sample test data

• Step Definitions• Setup• Tear down• Regular Expressions for each Given/When/Then

• Executable C# test code

Writing Executable Requirements

Given/When/Then

What is SpecFlow• .Net tool to write Executable Requirement in Gherkin

format• Integrates with Visual Studio

• Use File->New templates for creating new feature files• Glue between Feature and Step Definition files

• Gives VS debugger support• Set breakpoints on Given/When/Then lines in your .feature files

• Integrates with your existing CI infrastructure• Also integrates with

• NUnit• Selenium• WatiN

Good Executable Requirements• Understandable to developer• Understandable to business• Unambiguous• Automated• Run frequently

Writing Executable Requirements

Writing Executable Requirements• Features file

• Feature description• Scenario Outline

• Given/When/Then

• Examples• Sample test data

Feature File

Writing Executable Requirements• Step Definitions

• Setup• Tear down• Regular Expressions for each Given/When/Then

• Executable C# test code

SpecFlow Glue

Demo• SpecFlow demo

Sample Features files

Feature: Account Holder withdraws cash In order to have access to my money

As an Account Holder

I want to withdraw cash from an ATM

Scenario: Card has been disabled Given card is disabled

When the account holder requests money

Then the ATM should retain the card

And the ATM should say the card has been retained

Sample Features files

Feature: Serve coffee

In order to earn money

Customers should be able to

buy coffee at all times

Scenario: Buy last coffee

Given there are 1 coffees left in the machine

And I have deposited $1

When I press the coffee button

Then I should be served a coffee

What Languages are supported• Languages

• C# - Specflow, Cuke4Nuke, StorEvil• Ruby – Cucumber• Java – Cuke4Duke• Also Phython, PHP etc.

• Tools• Cucumber• Selenium RC• Fitnesse

Tear Down• BDD or Coding the right thing• Outside in Development• Works well in Scrum teams

• BA does feature file• Developer/tester does step definitions and C# test files

• Works well with VS10

Resources

URLshttp://www.specflow.org

http://dannorth.net/whats-in-a-story/

http://www.codeproject.com/KB/architecture/BddWithSpecFlow.aspx

http://cukes.info

Books