#912 add excluded params to proxy mapping

src/WireMock.Net/Serialization/ProxyMappingConverter.cs

@@ -31,6 +31,7 @@ public ProxyMappingConverter(WireMockServerSettings settings, IGuidUtils guidUti
         var useDefinedRequestMatchers = proxyAndRecordSettings.UseDefinedRequestMatchers;
         var excludedHeaders = new List<string>(proxyAndRecordSettings.ExcludedHeaders ?? new string[] { }) { "Cookie" };
         var excludedCookies = proxyAndRecordSettings.ExcludedCookies ?? new string[0];
+        var excludedParams = proxyAndRecordSettings.ExcludedParams ?? new string[0];
 
         var request = (Request?)mapping?.RequestMatcher;
         var clientIPMatcher = request?.GetRequestMessageMatcher<RequestMessageClientIPMatcher>();
@@ -74,12 +75,21 @@ public ProxyMappingConverter(WireMockServerSettings settings, IGuidUtils guidUti
         {
             foreach (var paramMatcher in paramMatchers)
             {
-                newRequest.WithParam(paramMatcher.Key, paramMatcher.MatchBehaviour, paramMatcher.Matchers!.ToArray());
+                if (!excludedParams.Contains(paramMatcher.Key, StringComparer.OrdinalIgnoreCase))
+                {
+                    newRequest.WithParam(paramMatcher.Key, paramMatcher.MatchBehaviour, paramMatcher.Matchers!.ToArray());
+                }
             }
         }
         else
         {
-            requestMessage.Query?.Loop((key, value) => newRequest.WithParam(key, false, value.ToArray()));
+            requestMessage.Query?.Loop((key, value) =>
+            {
+                if (!excludedParams.Contains(key, StringComparer.OrdinalIgnoreCase))
+                {
+                    newRequest.WithParam(key, false, value.ToArray());
+                }
+            });
         }
 
         // Cookies

src/WireMock.Net/Settings/ProxyAndRecordSettings.cs

@@ -57,6 +57,12 @@ public string SaveMappingForStatusCodePattern
     [PublicAPI]
     public string[]? ExcludedHeaders { get; set; }
 
+    /// <summary>
+    /// Defines a list of params which will be excluded from the saved mappings.
+    /// </summary>
+    [PublicAPI]
+    public string[]? ExcludedParams { get; set; }
+
     /// <summary>
     /// Defines a list of cookies which will be excluded from the saved mappings.
     /// </summary>

test/WireMock.Net.Tests/WireMockServer.Proxy.cs

@@ -528,6 +528,48 @@ public async Task WireMockServer_Proxy_Should_exclude_ExcludedCookies_in_mapping
         Check.That(matchers).Contains("GoodCookie");
     }
 
+    [Fact]
+    public async Task WireMockServer_Proxy_Should_exclude_ExcludedParams_in_mapping()
+    {
+        // Assign
+        string path = $"/prx_{Guid.NewGuid()}";
+        var serverForProxyForwarding = WireMockServer.Start();
+        serverForProxyForwarding
+            .Given(Request.Create().WithPath(path))
+            .RespondWith(Response.Create());
+
+        var settings = new WireMockServerSettings
+        {
+            ProxyAndRecordSettings = new ProxyAndRecordSettings
+            {
+                Url = serverForProxyForwarding.Urls[0],
+                SaveMapping = true,
+                SaveMappingToFile = false,
+                ExcludedParams = new[] { "timestamp" }
+            }
+        };
+        var server = WireMockServer.Start(settings);
+        var defaultMapping = server.Mappings.First();
+        var param01 = "?timestamp=2023-03-23";
+        var param02 = "&name=person";
+
+        // Act
+        var requestMessage = new HttpRequestMessage
+        {
+            Method = HttpMethod.Post,
+            RequestUri = new Uri($"{server.Urls[0]}{path}{param01}{param02}"),
+            Content = new StringContent("stringContent"),
+        };
+        await new HttpClient().SendAsync(requestMessage).ConfigureAwait(false);
+
+        // Assert
+        var mapping = server.Mappings.FirstOrDefault(m => m.Guid != defaultMapping.Guid);
+        Check.That(mapping).IsNotNull();
+        var matchers = ((Request)mapping.RequestMatcher).GetRequestMessageMatchers<RequestMessageParamMatcher>().Select(m => m.Key).ToList();
+        Check.That(matchers).Not.Contains("timestamp");
+        Check.That(matchers).Contains("name");
+    }
+
     [Fact]
     public async Task WireMockServer_Proxy_Should_preserve_content_header_in_proxied_request_with_empty_content()
     {