# Rules of painless unit tests

DevFeed: [Rules of painless unit tests](<https://devfeed.tech/articles/rules-of-painless-unit-tests-26136.md>)

Original publisher: [Read original article](<https://vadzimv.dev/2021/09/30/painless-unit-tests.html>)

Author: Vadzimv Dev Blog

Published: 2021-09-30T07:00:00Z

Content type: tutorial

Language: en

Sources: [vadzimv Dev Blog](<https://devfeed.tech/sources/vadzimv-dev-blog.md>)

Topics: [Testing](<https://devfeed.tech/topics/testing.md>), [Refactoring](<https://devfeed.tech/topics/refactoring.md>)

Tags: [refactor](<https://devfeed.tech/tags/refactor.md>), [refactoring](<https://devfeed.tech/tags/refactoring.md>), [testing](<https://devfeed.tech/tags/testing.md>), [tests](<https://devfeed.tech/tags/tests.md>), [unit-tests](<https://devfeed.tech/tags/unit-tests.md>)

## AI overview

An article presents practical rules for writing useful unit tests that remain stable during refactoring. It recommends testing systems through their public APIs, keeping tests specific, isolating external factors, using test doubles appropriately, avoiding overspecification and implementation-detail checks, and using factory methods for test objects.

## Source excerpt

Rules that make unit tests useful.