Snapshot Testing
Snapshot testing is a strategy to ensure that the output of some code doesn’t change over time. It make writing tests very simple, it lets you record an output of some code once, save it as a unit test, and check that it stays the same. If it does change, it shows you the difference.
Insta
Insta is a crate that lets you to snapshot testing easily in Rust. It comes with a tool that lets you record the output, and shows you the diff.
Reading
Using Insta for Rust snapshot testing by Agustinus Theodorus
In this article, Agustinus explains how to use insta-rs to do snapshot testing in Rust.