There are several types of testing methodologies. You can have tests to measure performance by stressing your application with specific actions and checking whether it achieves the expected minimum results. Those are important, but not at this stage. We should focus on other kinds of tests.
Our goal is to have a test suite that ensures our code behaves as we designed it. To ensure that, we must have:
- Unit tests, to check individual code units, such as some functions
- Integration tests, to check whether external actions produce the expected results
Using these two types of test, and having a full code coverage, we'll be able to develop new features and run regression tests, which is just a fancy way of saying ...