Added example of Snapshot tests for catching broken contract in events

Sample/EventsVersioning/EventsVersioning.Tests/EventsVersioning.Tests.csproj

@@ -12,6 +12,7 @@
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>
+        <PackageReference Include="Verify.Xunit" Version="24.2.0" />
         <PackageReference Include="xunit" Version="2.8.0" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.8.0">
             <PrivateAssets>all</PrivateAssets>

Sample/EventsVersioning/EventsVersioning.Tests/SnapshotTesting/EventsSnapshotTests.ShoppingCartConfirmed_WithCompleteData_IsCompatible.verified.txt

@@ -0,0 +1,5 @@
+{
+  ShoppingCartId: Guid_1,
+  ClientId: anonymised,
+  ConfirmedAt: DateTimeOffset_1
+}

Sample/EventsVersioning/EventsVersioning.Tests/SnapshotTesting/EventsSnapshotTests.ShoppingCartConfirmed_WithOnlyRequiredData_IsCompatible.verified.txt

@@ -0,0 +1,4 @@
+{
+  ShoppingCartId: Guid_1,
+  ConfirmedAt: DateTimeOffset_1
+}

Sample/EventsVersioning/EventsVersioning.Tests/SnapshotTesting/EventsSnapshotTests.cs

@@ -0,0 +1,34 @@
+using System.Runtime.CompilerServices;
+
+namespace EventsVersioning.Tests.SnapshotTesting;
+
+public class EventsSnapshotTests
+{
+    private record ShoppingCartConfirmed(
+        Guid ShoppingCartId,
+        string? ClientId,
+        DateTimeOffset ConfirmedAt
+    );
+
+    [Fact]
+    public Task ShoppingCartConfirmed_WithCompleteData_IsCompatible()
+    {
+        var @event = new ShoppingCartConfirmed(Guid.NewGuid(), "Oskar Dudycz", DateTimeOffset.UtcNow);
+        return Verify(@event);
+    }
+
+    [Fact]
+    public Task ShoppingCartConfirmed_WithOnlyRequiredData_IsCompatible()
+    {
+        var @event = new ShoppingCartConfirmed(Guid.NewGuid(), null, DateTimeOffset.UtcNow);
+        return Verify(@event);
+    }
+}
+// note this is optional, if you really need to
+// This is just showing that you can
+public static class StaticSettingsUsage
+{
+    [ModuleInitializer]
+    public static void Initialize() =>
+        VerifierSettings.AddScrubber(text => text.Replace("Oskar Dudycz", "anonymised"));
+}