FIRST Principles Of Testing

Introduction

FIRST is an acronym that stands for four principles of automated testing:

• Fast: Automated tests should be fast to execute so that developers can run them frequently without disrupting their workflow.

• Independent: Automated tests should be independent of one another so that a failure in one test does not cause a cascading failure in other tests.

• Repeatable: Automated tests should be repeatable and produce the same results every time they are run, regardless of the environment or external factors.

• Self-validating: Automated tests should be self-validating, meaning that they should have a clear pass/fail outcome that can be easily determined.

• Timely: Tests are written at the right time, immediately before the code that makes the tests pass. While it seems reasonable to take a more existential stance, that it does not matter when they're written as long as they are written, but this is wrong. Writing the test first makes a difference.