Writing tests is one of the most important and tedious task a developer has to do. A test is more than proving something is working in a project - even if it's main goal, it's also a way to see how an API is working, by offering implicit use cases and representing data using different format (mocking).
It's usually a good practice to create the test first and then implement the solution. This is the foundation of both Test-driven Development (TDD) and Extreme Programming (XP) methodologies.
In TDD, the test must be written first, and must fail. During the next iteration, the developer will invest time and effort to ensure the test is passing. In XP, this is practically the same, except this methodology has been created for high speed development (game production), and the tests are also used as source of trust and documentation.
This post is not really about those methodologies, even if we can talk a bit about them, one will find more accurate resources on Wikipedia or elsewhere than reading this publication. The goal of this article is to summarize the different ways available to test an application in Dart. Dart only, not Flutter, this is a different beast, and a dedicated article will be created only for it.
