# Test suites as classifiers

DevFeed: [Test suites as classifiers](<https://devfeed.tech/articles/test-suites-as-classifiers-21970.md>)

Original publisher: [Read original article](<https://blog.nelhage.com/post/test-suites-as-classifiers/>)

Author: Nelson Elhage

Published: 2020-03-01T20:34:00Z

Content type: opinion

Language: en

Sources: [Nelson Elhage](<https://devfeed.tech/sources/nelson-elhage.md>)

Topics: [test](<https://devfeed.tech/topics/test.md>), [Code](<https://devfeed.tech/topics/code.md>), [Development](<https://devfeed.tech/topics/development.md>), [bug](<https://devfeed.tech/topics/bug.md>), [incident](<https://devfeed.tech/topics/incident.md>)

Tags: [bug](<https://devfeed.tech/tags/bug.md>), [code](<https://devfeed.tech/tags/code.md>), [development](<https://devfeed.tech/tags/development.md>), [incident](<https://devfeed.tech/tags/incident.md>), [patches](<https://devfeed.tech/tags/patches.md>), [test](<https://devfeed.tech/tags/test.md>), [tests](<https://devfeed.tech/tags/tests.md>)

## AI overview

The article presents a test suite as a classifier that evaluates whether code changes are acceptable to apply and deploy. It explains that test results can produce false alarms or missed alarms, whose costs differ: missed alarms may allow bugs to reach production, while false alarms slow development.

## Source excerpt

Suppose we have some codebase we're considering applying some patch to, and which has a robust and maintained test suite. Considering the patch, we may ask, is this patch acceptable to apply and deploy. By this we mean to ask if the patch breaks any important functionality, violates any key properties or invariants of the codebase, or would otherwise cause some unacceptable risk or harm. In principle, we can divide all patches into "acceptable" or "unacceptable" relative to some project-specific notion of what we're willing to allow.