Unit Testing Basics

Unit Testing Basics

Serhiy Oplakanets @ Mavenresearch, November 2010Slides are not intended to make sense outside of the talk.

Thursday, November 18, 2010

A Discipline

• Unit Testing is a discipline of Quality Assurance

• Others Include:

• Functional Testing

• Integration Testing

• Code Review

• Continuous Integration

• ...


Unit Testing is

• validating that individual units of application work properly


Benefits

• Finding bugs early

• Less debugging

• Changes to application are safer and easier

• Examples of code usage

• Documentation (to some extent)

• Unit test is a tool to validate code design; in most cases code that is hard to test is badly designed


Good Unit Test

• Test only one unit at a time

• Do not depend on ordering of test run

• Runs fast

• Tests only one feature at a time

• Easy to understand

• Tests the public API of unit

• Covers all usage cases


Test Suite

• Multiple tests form Test Suite

• Your most important tool to check impact of changes

• Helps estimate changes


Good Unit Test Suite

• Is simple to run

• Runs fast (preferable in seconds)

• Is always Green

• Is non-interactive


Limitations of Unit Testing

• Not every bug can be found by unit tests

• As we're testing only one module -- integration issues are not covered

• Multi-threaded issues can't be caught by one-threaded test

• Hardware failures, 3rd party component issues, etc. All those can be covered only with a proper Functional Test Suite


Practical Session


Resources

• http://en.wikipedia.org/wiki/Unit_testing :)

• http://blog.stevensanderson.com/2009/08/24/writing-great-unit-tests-best-and-worst-practises/

• http://googletesting.blogspot.com/2008/11/clean-code-talks-unit-testing.html

• http://geosoft.no/development/


http://en.wikipedia.org/wiki/Unit_testing

http://en.wikipedia.org/wiki/Unit_testing

http://blog.stevensanderson.com/2009/08/24/writing-great-unit-tests-best-and-worst-practises/






http://googletesting.blogspot.com/2008/11/clean-code-talks-unit-testing.html




http://geosoft.no/development/unittesting.html

http://geosoft.no/development/unittesting.html

Thank you.


Technology

Unit Testing Basics