---
title: >
  Tests won't tell you if your code works
pubDate: 2023-06-29
permalink: >-
  archive/2023/06/29/tests-wont-tell-you-if-your-code-works
tags:
  - automated-testing
  - test-driven-development
---

Having a passing test suite or CI pipeline doesn't tell you if your appliction works.

There could be scenarios or edge-cases that aren't covered within the test suite and contain bugs, but aren't covered by the test suite.

There could be untested code that isn't covered at all.

A passing test suite proves that the tests that have been written so far pass and that there are no regressions introduced by the latest change.

## Here's the thing

Instead of telling you that your application works by passing, the test suite tells you something is broken when it fails.

If a previously-passing test is failing, the application is broken and should not be deployed - not that the application is working if the tests don't fail.