https://nanx.me/tags/testthat/ Recent content in testthat on Nan Xiao | 肖楠 Hugo -- gohugo.io en Sun, 05 Jan 2025 22:58:00 +0000 https://nanx.me/blog/post/testthat-snapshot-monkey-patch/ Sun, 05 Jan 2025 22:58:00 +0000 https://nanx.me/blog/post/testthat-snapshot-monkey-patch/ Memories instant photo. Photo by Kelly Sikkema. Problem Snapshot testing has been supported in testthat since testthat 3.0.0. By default, snapshot files are saved to a hardcoded directory: tests/testthat/_snaps/ Unfortunately, testthat does not provide a public API to customize this directory. This question has been raised in issues like r-lib/testthat#1623, suggesting that customizing the snapshot directory is a valid use case. Solution Without a public API, the most practical solution is to modify testthat’s internal behavior at runtime through monkey patching.