How to Write Good Unit Tests

It is probable that you have encountered numerous tests, or perhaps none at all (though this scenario is hopefully uncommon). If you belong to the former group, you may have experienced the laborious process of comprehending and constructing tests, which is painful for the eyes and patience. Despite the challenges, investing effort into test creation yields considerable benefits in the long term.

Consider a scenario where you aim to enhance your codebase. Upon conducting benchmarks, you identify sluggish and opaque segments within your code. What course of action do you take? Typically, you pinpoint these pain points and proceed to refactor with the expectation of improvement. Subsequently, after a period of refinement, say, several days or weeks, you manage to enhance performance substantially, perhaps achieving a 50% boost in efficiency—an outcome worthy of commendation in practical applications. However, what follows next? You contemplate merging your feature branch into the main codebase, yet uncertainty looms: Are you certain that all functionalities operate flawlessly? Are there comprehensive tests in place to validate that the end result remains consistent? Is there assurance that unintended consequences are not introduced to other areas of the codebase or experienced by users?