---
title: >
  Adding snapshot tests to Build Configs
pubDate: 2023-12-16
permalink: >-
  archive/2023/12/16/adding-snapshot-tests-to-build-configs
tags:
  - software-development
  - php
  - symfony
  - build-configs
  - automated-testing
  - test-driven-development
---

This week, I've started to add snapshot tests to the [Build Configs project][build configs].

I had unit tests for the DTO validation to ensure the configuration was correct, but the main thing I wanted to test was I could run it for a given configuration file and get the expected files and contents to be generated.

With snapshot tests, I generate the files for each configuration and compare them to a set that I know to be correct.

If the files match, the tests pass, but, if they don't - such as a bug in the code, the tests will fail.

This is the level that I want to be testing this project and that provides the most value.

If a snapshot test fails, I can try to replicate the underlying issue in a unit test whilst also fixing the snapshot test.

[build configs]: https://www.oliverdavies.dev/build-configs