Testing Principles

Out of Glenford Myers, ``The Art of Software Testing'':

A necessary part of a test case is a definition of the expected output or result.

A programmer should avoid attempting to test his or own program.

A programming organization should not test its own programs.

Thoroughly inspect the results of each test.

Test cases must be written for invalid and unexpected, as well as valid and expected, input conditions.

Examining a program to see if it does not do what it is supposed to do is only half of the battle. The other half is seeing whether the program does what it is not supposed to do.

Avoid throw-away test cases unless the program is truly a throw-away program.

Do not plan a testing effort under the tacit assumption that no errors will be found.

The probability of the existence of more errors in a section of a program is proportional to the number of errors already found in that section.

	A necessary part of a test case is a definition of the expected output or result.
	A programmer should avoid attempting to test his or own program.
	A programming organization should not test its own programs.
	Thoroughly inspect the results of each test.
	Test cases must be written for invalid and unexpected, as well as valid and expected, input conditions.
	Examining a program to see if it does not do what it is supposed to do is only half of the battle. The other half is seeing whether the program does what it is not supposed to do.
	Avoid throw-away test cases unless the program is truly a throw-away program.
	Do not plan a testing effort under the tacit assumption that no errors will be found.
	The probability of the existence of more errors in a section of a program is proportional to the number of errors already found in that section.