snapshot-testing

Snapshot testing in .NET verifies API responses and object serialization by capturing output into `.verified.` baseline files and comparing subsequent runs against them. The Verify library automates this baseline capture for deterministic output validation.

You handle non-deterministic values like dates and GUIDs in snapshot tests by applying custom scrubbers. The Verify library uses these scrubbers to automatically remove or replace dynamic data, ensuring stable comparisons across test runs.

You can detect breaking changes in your assembly's public API surface by using PublicApiGenerator alongside snapshot testing. This approach verifies the public API of assemblies against a baseline snapshot to catch unintended modifications.

Yes, the Verify library works with XUnit through the Verify.Xunit dependency. This integration facilitates snapshot testing within your existing XUnit test suites to validate HTML rendering, strings, and streams.

The best way to prevent regression when refactoring data serialization is snapshot testing. By capturing the serialized output as a baseline, any accidental format changes during refactoring will fail the test and alert you to the regression.

Snapshot tests fail comparing HTTP responses with dynamic values because non-deterministic data differs between runs. Using Verify.Http with custom scrubbers to normalize these dynamic values ensures stable HTTP response verification.