CS 228 meeting -*- Outline -*-

* testing (HR 1.4, 1.5)

** strategies
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   TESTING STRATEGIES

top-down:
   make stubs for each function
   test main, then functions

bottom-up:
   write test harness for each function
   test functions, then main
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	we've written test harnesses before (e.g., for logistic diff)

	you can do both:
		in a team programming enviroment,
		one person can test main with stubs,
		others can test functions, then integrate

	this applies recursively, at each level of design

	advantages:
		top-down testing best if unsure of top logic
			may involve extra work if top logic is easy
		bottom-up may waste effort if top logic changes

** test oracles

	to test carefully, you need a plan for testing, not haphazard

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    TEST ORACLE

Input values	Predicted Output
================================
4 9 7^D		4 7 9
87^D		87
99 100^D	99 100
^D		
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	actually need to have the format correct too

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	EVALUATING TEST ORACLES

Correct outputs predicted?
Covers boundary conditions?
Covers error cases?
Covers all code in the program?
Covers all meaningful kinds of input?
Covers some "average" cases?
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	Philosophy: try to break it

	people get paid for being good testers.