Agile Technical Practices

Sandy Mamoli

@smamolwww.nomad8.com

unit testingacceptance testing

continuous integration

load testingrefactoring

TDD

pair programming

user stories

whole team

collective code ownership

coding standards

Quality

• Overview of Agile

• Agile Acceptance Testing

• Deployment pipeline (CI)

Agile

What is Agile?

• Software development framework

• Based on adaptive planning

• Used since 1995 (Scrum)

Responding to change

In Changed Form

Not Wanted Anymore

As Defined

In Changed Form Not Wanted Anymore As Defined

Features: 6 months

Standish  Group,  Chaos  Report

How does it work?

Incrementing one bit at a time

51 2 3 4

© Jeff Patton, all rights reserved, www.AgileProductDesign.com

Vertical slices - feedback & innovation

© Johnathan Rasmussen, The Agile Samurai

Working, shippable software

Build important things first

Technical excellence

Continuous improvement

Agile Quality

Cost of bugs

0

37.5

75.0

112.5

150.0

A more scientific way of saying this ...

1x 5x 10x20x

50x

>150

Reqs Design Code DevT AccT OpsSource: Standish Group

Agile Testing Quadrants

Agile Acceptance TestFunctional TestStory Test

Unit Tests

The dev’s view

unit testing

acceptance testing

exploratory testing

User Stories

“incrementing” builds one bit at a time

51 2 3 4

© Jeff Patton, all rights reserved, www.AgileProductDesign.com

Story&ID:&

Descrip/on:

photographerAs&a&...

I&want&to&...

So&that&...make some photo albums private

I can have a backup of my personalphotos online

Priority:

Size:

high

13

Photo album privacy

Acceptance(Criteria

1. I can set the privacy of photo albums2. I can see my private albums3. My private albums are not visible to others

Agile Acceptance Testing

Agile Testing Quadrants

Agile Acceptance TestFunctional TestStory Test

Unit Tests

Acceptance tests

• Check that the implementation matches the intent

• Focus on shared understanding by developers, testers and business people

• End to end

Scenarios

• Create a new private album

• Make a public album private

• Make a private album public

<vertical slices through the acceptance criteria>

Examples

Given I create an album named “My holiday”

When I choose to make it private

Then I can see the album “My holiday”

But Kai cannot see the album

Examples

Given ... <something we accept to be true>

When ...<indicates the event in a scenario>

Then ...<indicates the expected outcome>

<Melomel API>

Cucumber

• Features

• Scenarios

• Steps

• Cucumber command

cucumber: example

Featurescucumber: example

Scenarioscucumber: example

Stepscucumber: example

Cucumber commandcucumber: example

Cucumber commandcucumber: example

Cucumber commandcucumber: example

Good practices

• Hide unnecessary detail

• Make tests independent

• Don’t test absolutely everything

Scenario: transfer money (imperative)  Given I have $100 in checking

  And I have $20 in savings

  When I go to the transfer form

  And I select "Checking" from "Source Account"

  And I select "Savings" from "Target Account"

  And I fill in "Amount" with "15"  And I press "Execute Transfer"  Then I should see that I have $85 in checking  And I should see that I have $35 in savings

Declarative vs. imperative style

Declarative vs. imperative style

Scenario: transfer money (declarative)  Given I have $100 in checking  And I have $20 in savings  When I transfer $15 from checking to savings  Then I should have $85 in checking 

Make tests independent

• Maintenance

• Where did it fail?

• Parallelise

Don’t test absolutely everything

Unit Tests

Acceptance Tests

GUI Tests

Why I like ATDD

• Ensures the intent is well understood

• Ensures the implementation matches the intent

• Ensures the implementation keeps matching the intent

Living documentation

Unit testing

Agile Testing Quadrants

Agile Acceptance TestFunctional TestStory Test

Unit Tests

Unit tests

• Check that the program behaves as the developer thinks it should

• Tend to be focussed on the structural (internal) quality of the code

• Hard for testers and business people to understand

• FlexUnit

• MXUnit

Unit tests/TDD

Deployment Pipeline

Agile Testing Quadrants

Agile Acceptance TestFunctional TestStory Test

Unit Tests

As often as possible to get early and instant feedback

Deployment pipeline

Deployment pipeline: Jez Humble, www.continuousdelivery.com

Agile deployment pipeline

Deployment pipeline: Jez Humble, www.continuousdelivery.com

• Create deployable artifacts

• Or fail fast and notify the team

• Triggered by CI server

• 5 minutes or less to run

• Jenkins, TeamCity, etc

Deployment pipeline: Commit stage

Continuous integration is a practice not a tool

• Commit regularly (at least once a day)

• Fix any broken build immediately

• Write automated tests

• Verify acceptance criteria have been met

• Verify business value

• Run in parallel

• Refactor

Deployment pipeline: Acceptance test stage

How to get started

• Create a walking skeleton with placeholders

• Automate the build and deploy process

• Automate unit tests and code analysis

• Automate acceptance tests

• Evolve the pipeline

Recommended reading

++

Call to action

• Work on Melomel & Cucumber

• Participate in CI projects (Jenkins)

• Steal from Ruby on Rails :-)

Contact meSandy Mamoli

@smamolsandy@nomad8.com