Add approval tests (#25)

Author: sungam3r

src/Destructurama.JsonNet.Tests/Approval/ApiApprovalTests.cs

@@ -0,0 +1,39 @@
+// Copyright 2017 Serilog Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using PublicApiGenerator;
+using Shouldly;
+using Xunit;
+
+namespace Destructurama.JsonNet.Tests;
+
+/// <summary>Tests for checking changes to the public API.</summary>
+public class ApiApprovalTests
+{
+    /// <summary>Check for changes to the public APIs.</summary>
+    /// <param name="type">The type used as a marker for the assembly whose public API change you want to check.</param>
+    [Theory]
+    [InlineData(typeof(LoggerConfigurationAppSettingsExtensions))]
+    public void PublicApi_Should_Not_Change_Unintentionally(Type type)
+    {
+        string publicApi = type.Assembly.GeneratePublicApi(new()
+        {
+            IncludeAssemblyAttributes = false,
+            AllowNamespacePrefixes = ["System", "Microsoft.Extensions.DependencyInjection"],
+            ExcludeAttributes = ["System.Diagnostics.DebuggerDisplayAttribute"],
+        });
+
+        publicApi.ShouldMatchApproved(options => options.NoDiff().WithFilenameGenerator((testMethodInfo, discriminator, fileType, fileExtension) => $"{type.Assembly.GetName().Name!}.{fileType}.{fileExtension}"));
+    }
+}

src/Destructurama.JsonNet.Tests/Approval/Destructurama.JsonNet.approved.txt

@@ -0,0 +1,7 @@
+namespace Destructurama
+{
+    public static class LoggerConfigurationAppSettingsExtensions
+    {
+        public static Serilog.LoggerConfiguration JsonNetTypes(this Serilog.Configuration.LoggerDestructuringConfiguration configuration) { }
+    }
+}