I am writing in response to the blog post at https://www.guru99.com/software-testing-seven-principles.html titled “7 Software Testing Principles: Learn with Examples”.
This blog post highlights some useful general guidelines for software testing. In order to write effective test cases, it is important to follow some logical approach toward determining what to test for and how to test it, and this is a guide that describes such a set of principles to follow that are well suited to capture the logic involved in software testing.
The first principle is that exhaustive testing is not possible. I am not sure I believe this. In general it is useful to assume there exists no perfect test, but for simple enough applications where the number of possible interactions are enumerable, I would think that it would be possible to achieve exhaustive testing, much like an exhaustive proof, where every possible path is covered and verified. Maybe I am missing the implausible event that the test is correct but the computer running the tests is corrupted in such a way that certain tests are not run. This is relevant to a point made in this area, which is risk assessment.
The second and third principles make similar points. Always running the same tests will eventually not cover certain issues. If all of the same methods for testing are always applied exactly the same, then eventually there will be some scenario which the particular method is not suited for, and it will miss something. This leads into the later principles: the absence of a failure is not proof of success, and context is important. Developing tests suited for the particular application is necessary to ensure the correlation between tests passing and the program functioning correctly, and just because every test passed does not mean the program is going to work perfectly.
This set of software testing principles can be summarized in a few basic points. Develop test cases that are well suited specifically for the application that is being tested, consider the risk of certain operations causing a failure, and do not assume that everything works perfectly just because every test case passed.