Why testers should know about TDD and how we can use it?

Raimond Sinivee, @RaimondSinivee

05.06.2015 @ntd2015

Agenda

• Terminology

• The Exercise

• The Problem

• The Story

• Unit testing and TDD

• The Testing Pyramid

• How testers could use TDD when they code software that helps in testing?

• The Exercise continues

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Terminology

1. Tools, scripts, harness, framework, helpers but not automation

2. There are no best practices, there are heuristics.

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Small example how TDD would look like in case of Selenium is the play• Download

• Java:• Source: http://1drv.ms/1RL14lp (3KB)

• Java libs: http://1drv.ms/1RKYsDO (26MB)

• Pyhton: App\python.exe src\SeleniumExample.py• Source http://1drv.ms/1RKYRX2 (1KB)

• Portable with Source http://1drv.ms/1RKYwU4 (37MB)

• Implement new method to SeleniumExample which would add to http protocol to a URL• Input “www.google.ee” returns http://www.google.ee

• Input “www.bing.com” returns http://www.bing.com

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Testing purpose code is first class citizen

• Regressions• Low first time quality

• Unknown state of code

• Problematic testing tools• Inaccurate

• Instable

• Not understandable code nor results

• Are your tests actually able to find the concern that they supposed to?

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Getting started

• Went to developer events, community gatherings, courses• CODE KATA

• Peer for troubleshooting

• Fix a bug

• Break down the wall

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Unit testing and Test Driven Development

• Unit test covers a single intent of a method

• TDD is a code design method• unit tests should be written before the code

• … but we have unit tests!• How would a development process look like when you write your tests before

the code or after the code?

• Don't test implementation, test intent

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The Test Pyramid

•Amount of tests

•Lines of Code

•Time to execute

•Time to understand failures

•Purpose

•Role@ntd2015, @RaimondSinivee

How testers could use TDD when they code software that helps in testing?• Developing testing tools

• Duplication

• Naming

• Troubleshooting• Debugging vs. unit testing

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What TDD gives to testers?

• Red – Green – Refactor mindset

• Testability: controllability and observability

• Fast feedback loop

• Do you practice what you talk about?

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Summary

• Red – Green – Refactor mindset

• Testability: controllability and observability

• Unit test before coding to test intent, remove duplication and improve naming

• Troubleshoot by writing unit tests

• @ntd2015, @RaimondSinivee

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Implementation ideas

• Add support for subdomain as input parameter to URL generation method in SeleniumExample• Input “www” returns http://www.google.de

• Input “” returns http://google.de

• Method to start specific driver.• IE, Chrome, Firefox, Safari

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Appendix

• Open Lecture by James Bach on Software Testing https://www.youtube.com/watch?v=ILkT_HV9DVU

• Test Pyramid: Initial idea author Mike Cohn, Succeeding with Agile: Software Development Using Scrum

• Book: Design Patterns: Elements of Reusable Object-Oriented Software, Gang of four.

• Is TDD dead: https://www.youtube.com/results?search_query=is+tdd+dead

• https://www.youtube.com/watch?v=vqwyMaHcjQE James Bach about testing agile process

• TDD for Testers What does TDD mean for me, the Tester?http://www.ministryoftesting.com/2014/08/tdd-testers/

• Integration Tests Are a Scam http://www.infoq.com/presentations/integration-tests-scam

• 7 Popular Unit Test Naming Conventions http://java.dzone.com/articles/7-popular-unit-test-naming

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