syrupy

syrupy is a zero-dependency pytest plugin for snapshot testing. It lets tests assert that computed results do not change, by comparing them with snapshots stored alongside the tests.

Assertions are written in an idiomatic way, such as assert x == snapshot, so snapshot tests fit naturally among other pytest tests. Snapshots are created or updated with a command-line option, unused snapshots are reported, and serialisation can be extended to support new data types. Extensions are provided for formats such as JSON and images.

syrupy is free and open source under the MIT licence.