Nullean.Snapshots

Nullean.Snapshots runs journeys in dotnet test and keeps one transcript per journey as a snapshot: every checkpoint's output, compared as a tree, so a failure names what moved.

C# 
public class ShopJourneys(ShopServer server)
{
    [Test]
    [JourneyFiles("journeys")]
    public Task Run(SnapshotFile journey) =>
        JourneyTest.RunAsync(journey, new() { BaseUrl = server.Url });
}
  1. a test case per journeys/**/*.journey

Each journey is its own test case, named after its file (Run(checkout), Run(admin/users)). A folder that needs other setup gets its own class with a more specific folder. Screenshots and HAR files go next to the journey's received transcript.

Shell 
snap journey run journeys/checkout.journey --base-url http://localhost:5000/

A test and snap journey run share the same verified file, keyed by the journey's path. See browser journeys in the Nullean.Snapshots docs.

Checks fit snapshots well when their output is stable: a11y, links, network requests and errors print deterministic lists, and timings and vitals with --budget print only whether each reading is within its limit.

The same project snapshots HTTP APIs too: .http files run against any HttpClient, every response compared by status, chosen headers and JSON body, secrets redacted. See HTTP.