The F.I.R.S.T. Rule For Writing Tests

There are the F.I.R.S.T. rules for writing tests. Clean tests follow five other rules that form the above acronym:

• Fast: Tests should be fast.
• Independent: Tests should not depend on each other.
• Repeatable: Tests should be repeatable in any environment.
• Self-Validating: Tests should have a boolean output.
• Timely: Tests need to be written in a timely fashion.

Original text from Clean Code: Reference.