Slides form very basic introductory talk about unit testing.

1. Unit Testing Basics
Serhiy Oplakanets @ Mavenresearch, November 2010
Slides are not intended to make sense outside of the talk.
Thursday, November 18, 2010

2. A Discipline
• Unit Testing is a discipline of Quality Assurance
• Others Include:
• Functional Testing
• Integration Testing
• Code Review
• Continuous Integration
• ...
Thursday, November 18, 2010

3. Unit Testing is
• validating that individual units of
application work properly
Thursday, November 18, 2010

4. 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
Thursday, November 18, 2010

5. 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
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6. Test Suite
• Multiple tests form Test Suite
• Your most important tool to check impact
of changes
• Helps estimate changes
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7. Good Unit Test Suite
• Is simple to run
• Runs fast (preferable in seconds)
• Is always Green
• Is non-interactive
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8. 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
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9. Practical Session
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10. 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/
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11. Thank you.
Thursday, November 18, 2010