This is a snapshot testing framework for Swift that records and compares reference images or data representations to detect regressions in application state. It functions as a visual regression testing tool and a data snapshotting library, converting complex types into stable formats to verify internal state and object properties.
The framework utilizes a multi-format snapshot strategy, allowing values to be represented as images, strings, or data blobs. It includes a mechanism for defining custom snapshot strategies to convert specific data types into comparable formats based on custom logic.
The tool covers visual testing through device-agnostic view capture and image rendering across multiple configurations and orientations. It also provides textual state rendering for data consistency verification and supports asynchronous value snapshotting for states that depend on callbacks or background processes.
Failure messages can generate command-line strings to facilitate the use of external diff tools for visualizing differences.