Can you explain what the FIRST principle means in the context of software testing?

The FIRST principle in software testing is a set of criteria that good unit tests should meet. The abbreviation stands for:

• Fast — tests should run very quickly so they can be executed frequently.
• Independent — tests should not depend on each other, and their order of execution should not affect the outcome.
• Repeatable — tests should produce the same result when run multiple times in any environment.
• Self-Validating — tests should automatically determine whether they pass or fail without manual checking.
• Timely — tests should be written at the right time, usually alongside the code or immediately after.

This principle helps create high-quality and maintainable tests that facilitate development and code support.