Figure out what problem you are solving. Test individual methods - - PDF document

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TOPICS

• Engineering Methodology
• Requirements, Algorithm, Example, Coding
• Testing and Debugging
• Testing methodologies

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Program Debugging (Special Topic)

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Engineering Methodology Requirements Algorithm Example Coding Test and Debug

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™ Figure out what problem you are solving. ™ Read the specification very carefully. ™ Figure out how to solve the problem, on paper. ™ Make an example of the centerline case. ™ Add corner cases and error handling later. ™ Incremental development is more effective. ™ Test each piece by itself.

Think before coding! More Detail

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™ Test individual methods before using them. ™ Not just centerline, also boundary conditions. ™ Debug your code in a methodical fashion. ™ Thoroughly investigate any anomalies in behavior. ™ Make sure to test all the branches in your code. ™ Anything can be debugged, given enough time.

If you haven’t tested it, it doesn’t work!

Testing and Debugging

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™ Add a print statement after every operation. ™ Check the values against your example. ™ Run several times with different input data. ™ Remove or comment out print statements. ™ Verify against test suite, if available. ™ Check against the assignment specification.

Tedious, but effective, and guaranteed to improve assignment scores.

Print Debugging

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™ Eclipse makes debugging easy. ™ Run the program in debug mode (demo). ™ Learn how to set breakpoints. ™ Single stepping: ‘step into’ versus ‘step over’. ™ Can examine current values of all variables. ™ More advanced features available.

This is how professional programmers debug their code.

Debugging Tools

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Eclipse Debugging (1) Starting a debugging session.

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Eclipse Debugging (2) Setting breakpoints in code.

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Eclipse Debugging (3) Examining the values of variables.

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™ Unit Testing: verify that each method works. ™ Module Testing: verify that each class works. ™ Integration: verify that classes interact correctly. ™ System Testing: verify that system works as desired. ™ Black Box versus White Box testing ™ Centerline testing versus Corner Cases ™ Checking that Error Conditions are handled ™ Test Driven Development: what is it?

Testing Methodologies

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