Add some more tests

src/WireMock.Net/Matchers/IIgnoreCaseMatcher.cs

@@ -0,0 +1,13 @@
+namespace WireMock.Matchers
+{
+    /// <summary>
+    /// IIgnoreCaseMatcher
+    /// </summary>
+    public interface IIgnoreCaseMatcher : IMatcher
+    {
+        /// <summary>
+        /// Ignore the case.
+        /// </summary>
+        bool IgnoreCase { get; }
+    }
+}

src/WireMock.Net/Matchers/RegexMatcher.cs

@@ -10,7 +10,7 @@ namespace WireMock.Matchers
     /// Regular Expression Matcher
     /// </summary>
     /// <seealso cref="IStringMatcher" />
-    public class RegexMatcher : IStringMatcher
+    public class RegexMatcher : IStringMatcher, IIgnoreCaseMatcher
     {
         private readonly string[] _patterns;
         private readonly Regex[] _expressions;
@@ -34,6 +34,7 @@ namespace WireMock.Matchers
             Check.NotNull(patterns, nameof(patterns));
 
             _patterns = patterns;
+            IgnoreCase = ignoreCase;
 
             RegexOptions options = RegexOptions.Compiled;
             if (ignoreCase)
@@ -73,5 +74,8 @@ namespace WireMock.Matchers
         {
             return "RegexMatcher";
         }
+
+        /// <inheritdoc cref="IIgnoreCaseMatcher.IgnoreCase"/>
+        public bool IgnoreCase { get; }
     }
 }

src/WireMock.Net/Matchers/Request/RequestMessageBodyMatcher.cs

@@ -104,15 +104,13 @@ namespace WireMock.Matchers.Request
         {
             if (requestMessage.Body != null)
             {
-                var stringMatcher = Matcher as IStringMatcher;
-                if (stringMatcher != null)
+                if (Matcher is IStringMatcher stringMatcher)
                 {
                     return stringMatcher.IsMatch(requestMessage.Body);
                 }
             }
 
-            var objectMatcher = Matcher as IObjectMatcher;
-            if (objectMatcher != null)
+            if (Matcher is IObjectMatcher objectMatcher)
             {
                 if (requestMessage.BodyAsJson != null)
                 {