Add WithBodyAsType to RequestMatcher (#1388)

* Add WithBody<T>

* .

* t

* t2

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;
+    }
+}