Asserting Quality by Test Driven Development (TDD)

Presented at : Broad basing Agile Implementation Conference (Jul 31, 2012 , Bangalore – India ) (http://www.qaiglobalservices.com/Design/uploaded_mailers/agile_clinic/agile_clinic_online.html)

Raghavendra Mithare – Lead Coach, (rmithare@ciber.com)

Aravindan Manoharan - Principal Consultant, ADM Practice(amanoharan@ciber.com)

Ciber India (www.ciber.com)

… a Zen story !

Craft v/s Engineering

CMMI and Agile• OPD• OPF• OT

Process Management

• DAR• M&A• PPQA• CM

Support

• IPM• PP• PMC• REQM• RSKM

Project Management

• PI• RD• TS• VER• VAL

Engineering

Test Driven Development - recap1. Test Driven Development

• Create automated unit tests that define code requirements

• Tests contain assertions • confirms correct behavior as developers

evolve and refactor • Use testing frameworks based on xUnit • Define features as test cases • Produces code necessary to pass that

iteration's tests. • Refactor code to accommodate changes

Pass

Requirements

Develop Test Cases

Add/ Update / Delete Code

New Requirement?

Execute Test Cases

Fail

Yes

Stop Development

NoVerb: refactor(computing) restructure or rewrite source code to improve internal consistency, readability, etc, without changing its function

TDD and CMMI Requirements Development • Acceptance Test Cases provided by product owner • Write Unit Test Cases during the Development

Technical Solution • Implement the design to meet the requirements • Refactor the Design once all the test cases are passed

Validation • Rich set of tests developed to ensure the “right” product is developed• Faster validation to regress the entire application in a short span of time

TDD and CMMI

Verification• Review of Tests to meet the business

requirements and design• Execution of tests as part of the review process

Product Integration • Tests to validate the impacting areas of the

application and other interfaces

Benefits• High quality

• Fewer defects• Loose coupling, high cohesion• Design validated by tests

• More efficient code-test activity• By automation of rich set of test cases

• Can refactor with confidence• Code is malleable• Design is robust (tested, flexible)

Benefits• Living specification

• Expressed as client needs, not code capabilities• Built-in sample code• Built-in diagnostics

• Developer momentum, based on success

Number of Tests

Confi

denc

e

Benefits• Metrics

• Unit Test case code coverage 71%• Total Automation percentage 89% (because of TDD and Acceptance

TDD)• Defect density of 2.5 defects /KLOC

Project Duration

Testi

ng T

ime

TDD

When a thing is new, people say, ’It is not true.”

Later, when its truth becomes oblivious, they say,

‘It is not important.’Finally, when its importance cannot be

denied,They say, ‘Anyway, it is not new.’

William James

Thanks

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contact• Raghavendra (Raghav) Mithare : Mithare@gmai.com• https://www.linkedin.com/in/raghavendramithare