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Get Started

This Snapshooter Get Started has been created for the xUnit Test Framework. Snapshooter is also available for MsTest and NUnit Testing, the test procedure is exactly the same.

Install Snapshooter

To validate your test result with snapshots in Xunit, just install the Snapshooter Xunit package:

dotnet add package Snapshooter.Xunit

(for MsTest --> Snapshooter.MsTest or for NUnit Snapshooter.NUnit)

Create a Snapshot

Insert a snapshot assert statement Snapshot.Match(yourResultObject); into your unit test to create a snapshot.

During the test run, the Snapshot.Match(person) statement creates a new snapshot of your result object and stores it in the __snapshots__ folder.

Example:

[Fact]
public void CreatePersonSnapshotTest()
{
    // arrange
    var serviceClient = new ServiceClient();

    // act
    TestPerson person = serviceClient.CreatePerson(
        Guid.Parse("2292F21C-8501-4771-A070-C79C7C7EF451"), "David", "Mustermann");

    // assert
    Snapshot.Match(person);
}

The __snapshots__ folder is always next to your executed unit test file.

Review your Snapshot

Review your new snapshot file __snapshots__/<UnitTestClassName>.<TestMethodName>.snap if the data inside is what you expect.

Rerun your Test

Now in every execution of your Test, the Snapshot.Match(person) statement will create again a snapshot of your test result and compares it against your reviewed snapshot in the __snapshots__ folder.

If your snapshot and your test result do not match with each other, then your test will fail with a snapshot mismatch exception. How you can handle/solve such a Snapshot Mismatch have a look here.

Snapshooter is very flexible, therefore you can give your snapshots your own name, or you can ignore specific properties of your test results.