Add WithBodyAsType to RequestMatcher

src/WireMock.Net.Minimal/Matchers/Request/RequestMessageBodyMatcher`1.cs

@@ -0,0 +1,60 @@
+// Copyright © WireMock.Net
+
+using System;
+using Newtonsoft.Json.Linq;
+using Stef.Validation;
+
+namespace WireMock.Matchers.Request;
+
+/// <summary>
+/// The request body matcher.
+/// </summary>
+public class RequestMessageBodyMatcher<T> : IRequestMatcher
+{
+    /// <summary>
+    /// The body data function for type T
+    /// </summary>
+    public Func<T?, bool>? Func { get; }
+
+    /// <summary>
+    /// The <see cref="MatchOperator"/>
+    /// </summary>
+    public MatchOperator MatchOperator { get; } = MatchOperator.Or;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="RequestMessageBodyMatcher"/> class.
+    /// </summary>
+    /// <param name="func">The function.</param>
+    public RequestMessageBodyMatcher(Func<T?, bool> func)
+    {
+        Func = Guard.NotNull(func);
+    }
+
+    /// <inheritdoc />
+    public double GetMatchingScore(IRequestMessage requestMessage, IRequestMatchResult requestMatchResult)
+    {
+        var (score, exception) = CalculateMatchScore(requestMessage).Expand();
+        return requestMatchResult.AddScore(GetType(), score, exception);
+    }
+
+    private MatchResult CalculateMatchScore(IRequestMessage requestMessage)
+    {
+        if (Func != null)
+        {
+            if (requestMessage.BodyData?.BodyAsJson is JObject jsonObject)
+            {
+                try
+                {
+                    var bodyAsT = jsonObject.ToObject<T>();
+                    return MatchScores.ToScore(Func(bodyAsT));
+                }
+                catch (Exception ex)
+                {
+                    return new MatchResult(ex);
+                }
+            }
+        }
+
+        return default;
+    }
+}

src/WireMock.Net.Minimal/RequestBuilders/Request.WithBody.cs

@@ -34,13 +34,6 @@ public IRequestBuilder WithBody(object body, MatchBehaviour matchBehaviour = Mat
         return this;
     }
 
-    /// <inheritdoc />
-    public IRequestBuilder WithBodyAsJson(object body, MatchBehaviour matchBehaviour = MatchBehaviour.AcceptOnMatch)
-    {
-        var matcher = body as IMatcher ?? new JsonMatcher(matchBehaviour, body);
-        return WithBody([matcher]);
-    }
-
     /// <inheritdoc />
     public IRequestBuilder WithBody(IMatcher matcher)
     {
@@ -98,4 +91,20 @@ public IRequestBuilder WithBody(Func<IDictionary<string, string>?, bool> func)
         _requestMatchers.Add(new RequestMessageBodyMatcher(Guard.NotNull(func)));
         return this;
     }
+
+    /// <inheritdoc />
+    public IRequestBuilder WithBodyAsJson(object body, MatchBehaviour matchBehaviour = MatchBehaviour.AcceptOnMatch)
+    {
+        var matcher = body as IMatcher ?? new JsonMatcher(matchBehaviour, body);
+        return WithBody([matcher]);
+    }
+
+    /// <inheritdoc />
+    public IRequestBuilder WithBodyAsType<T>(Func<T?, bool> func)
+    {
+        Guard.NotNull(func);
+
+        _requestMatchers.Add(new RequestMessageBodyMatcher<T>(func));
+        return this;
+    }
 }

src/WireMock.Net.Minimal/RequestBuilders/Request.cs

@@ -29,7 +29,7 @@ public partial class Request : RequestMessageCompositeMatcher, IRequestBuilder
     /// <returns>The <see cref="IRequestBuilder"/>.</returns>
     public static IRequestBuilder Create()
     {
-        return new Request(new List<IRequestMatcher>());
+        return new Request([]);
     }
 
     /// <summary>

src/WireMock.Net.Shared/RequestBuilders/IBodyRequestBuilder.cs

@@ -80,6 +80,14 @@ public interface IBodyRequestBuilder : IMultiPartRequestBuilder
     /// <returns>The <see cref="IRequestBuilder"/>.</returns>
     IRequestBuilder WithBody(Func<object?, bool> func);
 
+    /// <summary>
+    /// WithBody: func (type)
+    /// </summary>
+    /// <typeparam name="T">The type.</typeparam>
+    /// <param name="func">The function.</param>
+    /// <returns>The <see cref="IRequestBuilder"/>.</returns>
+    IRequestBuilder WithBodyAsType<T>(Func<T?, bool> func);
+
     /// <summary>
     /// WithBody: func (BodyData object)
     /// </summary>

test/WireMock.Net.Tests/RequestBuilders/RequestBuilderWithBodyTests.cs

@@ -1,11 +1,12 @@
 // Copyright © WireMock.Net
 
 using System;
-using FluentAssertions;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using FluentAssertions;
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 using NFluent;
 using WireMock.Matchers;
 using WireMock.Matchers.Request;
@@ -72,15 +73,17 @@ public void Request_WithBody_FuncString()
     }
 
     [Fact]
-    public void Request_WithBody_FuncJson()
+    public void Request_WithBody_FuncObject()
     {
         // Assign
-        var requestBuilder = Request.Create().UsingAnyMethod().WithBody(b => b != null);
+        var requestBuilder = Request.Create()
+            .UsingAnyMethod()
+            .WithBody(b => b != null);
 
         // Act
         var body = new BodyData
         {
-            BodyAsJson = 123,
+            BodyAsJson = JObject.Parse("""{ "X": 123, "Y": "a" }"""),
             DetectedBodyType = BodyType.Json
         };
         var request = new RequestMessage(new UrlDetails("http://localhost/foo"), "POST", ClientIp, body);
@@ -90,6 +93,57 @@ public void Request_WithBody_FuncJson()
         Check.That(requestBuilder.GetMatchingScore(request, requestMatchResult)).IsEqualTo(1.0);
     }
 
+    [Theory]
+    [InlineData("""{ "X": 123, "Y": "a" }""", 1.0)]
+    [InlineData("""{ "X": 123, "Y": "b" }""", 0.0)]
+    public void Request_WithBodyAsType_Func(string json, double expected)
+    {
+        // Assign
+        var requestBuilder = Request.Create()
+            .UsingAnyMethod()
+            .WithBodyAsType<FuncType>(ft => ft != null && ft.X == 123 && ft.Y == "a");
+
+        // Act
+        var body = new BodyData
+        {
+            BodyAsJson = JObject.Parse(json),
+            DetectedBodyType = BodyType.Json
+        };
+        var request = new RequestMessage(new UrlDetails("http://localhost/foo"), "POST", ClientIp, body);
+
+        // Assert
+        var requestMatchResult = new RequestMatchResult();
+        Check.That(requestBuilder.GetMatchingScore(request, requestMatchResult)).IsEqualTo(expected);
+    }
+
+    [Fact]
+    public void Request_WithBodyAsType_Func_IncorrectType()
+    {
+        // Assign
+        var requestBuilder = Request.Create()
+            .UsingAnyMethod()
+            .WithBodyAsType<Version>(ft => ft != null);
+
+        // Act
+        var body = new BodyData
+        {
+            BodyAsJson = JObject.Parse("""{ "X": 123, "Y": "a" }"""),
+            DetectedBodyType = BodyType.Json
+        };
+        var request = new RequestMessage(new UrlDetails("http://localhost/foo"), "POST", ClientIp, body);
+
+        // Assert
+        var requestMatchResult = new RequestMatchResult();
+        Check.That(requestBuilder.GetMatchingScore(request, requestMatchResult)).IsEqualTo(0.0);
+    }
+
+    private class FuncType
+    {
+        public int X { get; set; } = 42;
+
+        public string Y { get; set; } = string.Empty;
+    }
+
     [Fact]
     public void Request_WithBody_FuncFormUrlEncoded()
     {