Allow removal of prefix when proxying to another server (#630) (#924)

* #630 Allow removal of prefix when proxying to another server

* #630 Rename replace to replace settings and ensure properties used in place of fields

* #630 Update replace settings type name to ProxyUrlReplaceSettings

* #630 Add admin model and update settings parser to parse new values

* Fix formatting issues

* #630 Ensure json mapping between admin model and internal model takes place

* #630 Refactor parsing and structure of extracting new proxy url

* Reduce function complexity

* #630 Fix line length issues and remove try prefix from parser methods

src/WireMock.Net.Abstractions/Admin/Settings/ProxyAndRecordSettingsModel.cs

@@ -68,4 +68,9 @@ public class ProxyAndRecordSettingsModel
     /// Append an unique GUID to the filename from the saved mapping file.
     /// </summary>
     public bool AppendGuidToSavedMappingFile { get; set; }
+
+    /// <summary>
+    /// Defines the Replace Settings
+    /// </summary>
+    public ProxyUrlReplaceSettingsModel? ReplaceSettings { get; set; }
 }

src/WireMock.Net.Abstractions/Admin/Settings/ProxyUrlReplaceSettingsModel.cs

@@ -0,0 +1,18 @@
+namespace WireMock.Admin.Settings;
+
+/// <summary>
+/// Defines an old path param and a new path param to be replaced when proxying.
+/// </summary>
+[FluentBuilder.AutoGenerateBuilder]
+public class ProxyUrlReplaceSettingsModel
+{
+    /// <summary>
+    /// The old path value to be replaced by the new path value
+    /// </summary>
+    public string OldValue { get; set; } = null!;
+
+    /// <summary>
+    /// The new path value to replace the old value with
+    /// </summary>
+    public string NewValue { get; set; } = null!;
+}

src/WireMock.Net/Proxy/ProxyHelper.cs

@@ -37,7 +37,9 @@ internal class ProxyHelper
         var requiredUri = new Uri(url);
 
         // Create HttpRequestMessage
-        var httpRequestMessage = HttpRequestMessageHelper.Create(requestMessage, url);
+        var replaceSettings = proxyAndRecordSettings.ReplaceSettings;
+        var proxyUrl = replaceSettings is not null ? url.Replace(replaceSettings.OldValue, replaceSettings.NewValue) : url;
+        var httpRequestMessage = HttpRequestMessageHelper.Create(requestMessage, proxyUrl);
 
         // Call the URL
         var httpResponseMessage = await client.SendAsync(httpRequestMessage, HttpCompletionOption.ResponseContentRead).ConfigureAwait(false);

src/WireMock.Net/Settings/ProxyAndRecordSettings.cs

@@ -69,6 +69,12 @@ public class ProxyAndRecordSettings : HttpClientSettings
     [PublicAPI]
     public string[]? ExcludedCookies { get; set; }
 
+    /// <summary>
+    /// Replace Settings
+    /// </summary>
+    [PublicAPI]
+    public ProxyUrlReplaceSettings? ReplaceSettings { get; set; }
+
     /// <summary>
     /// Prefer the Proxy Mapping over the saved Mapping (in case SaveMapping is set to <c>true</c>).
     /// </summary>

src/WireMock.Net/Settings/ProxyUrlReplaceSettings.cs

@@ -0,0 +1,17 @@
+namespace WireMock.Settings;
+
+/// <summary>
+/// Defines an old path param and a new path param to be replaced when proxying.
+/// </summary>
+public class ProxyUrlReplaceSettings
+{
+    /// <summary>
+    /// The old path value to be replaced by the new path value
+    /// </summary>
+    public string OldValue { get; set; } = null!;
+
+    /// <summary>
+    /// The new path value to replace the old value with
+    /// </summary>
+    public string NewValue { get; set; } = null!;
+}

src/WireMock.Net/Settings/WireMockServerSettingsParser.cs

@@ -21,7 +21,8 @@ public static class WireMockServerSettingsParser
     /// <param name="logger">The logger (optional, can be null)</param>
     /// <param name="settings">The parsed settings</param>
     [PublicAPI]
-    public static bool TryParseArguments(string[] args, [NotNullWhen(true)] out WireMockServerSettings? settings, IWireMockLogger? logger = null)
+    public static bool TryParseArguments(string[] args, [NotNullWhen(true)] out WireMockServerSettings? settings,
+        IWireMockLogger? logger = null)
     {
         Guard.HasNoNulls(args);
 
@@ -70,6 +71,17 @@ public static class WireMockServerSettingsParser
         settings.AcceptAnyClientCertificate = parser.GetBoolValue(nameof(WireMockServerSettings.AcceptAnyClientCertificate));
 #endif
 
+        ParseLoggerSettings(settings, logger, parser);
+        ParsePortSettings(settings, parser);
+        ParseProxyAndRecordSettings(settings, parser);
+        ParseCertificateSettings(settings, parser);
+
+        return true;
+    }
+
+    private static void ParseLoggerSettings(WireMockServerSettings settings, IWireMockLogger? logger,
+        SimpleCommandLineParser parser)
+    {
         var loggerType = parser.GetStringValue("WireMockLogger");
         switch (loggerType)
         {
@@ -86,22 +98,17 @@ public static class WireMockServerSettingsParser
                 {
                     settings.Logger = logger;
                 }
+
                 break;
         }
+    }
 
-        if (parser.Contains(nameof(WireMockServerSettings.Port)))
-        {
-            settings.Port = parser.GetIntValue(nameof(WireMockServerSettings.Port));
-        }
-        else if (settings.HostingScheme is null)
-        {
-            settings.Urls = parser.GetValues("Urls", new[] { "http://*:9091/" });
-        }
-
+    private static void ParseProxyAndRecordSettings(WireMockServerSettings settings, SimpleCommandLineParser parser)
+    {
         var proxyUrl = parser.GetStringValue("ProxyURL") ?? parser.GetStringValue("ProxyUrl");
         if (!string.IsNullOrEmpty(proxyUrl))
         {
-            settings.ProxyAndRecordSettings = new ProxyAndRecordSettings
+            var proxyAndRecordSettings = new ProxyAndRecordSettings
             {
                 AllowAutoRedirect = parser.GetBoolValue("AllowAutoRedirect"),
                 ClientX509Certificate2ThumbprintOrSubjectName = parser.GetStringValue("ClientX509Certificate2ThumbprintOrSubjectName"),
@@ -121,18 +128,27 @@ public static class WireMockServerSettingsParser
                 }
             };
 
-            string? proxyAddress = parser.GetStringValue("WebProxyAddress");
-            if (!string.IsNullOrEmpty(proxyAddress))
-            {
-                settings.ProxyAndRecordSettings.WebProxySettings = new WebProxySettings
-                {
-                    Address = proxyAddress!,
-                    UserName = parser.GetStringValue("WebProxyUserName"),
-                    Password = parser.GetStringValue("WebProxyPassword")
-                };
-            }
-        }
+            ParseWebProxyAddressSettings(proxyAndRecordSettings, parser);
+            ParseProxyUrlReplaceSettings(proxyAndRecordSettings, parser);
 
+            settings.ProxyAndRecordSettings = proxyAndRecordSettings;
+        }
+    }
+
+    private static void ParsePortSettings(WireMockServerSettings settings, SimpleCommandLineParser parser)
+    {
+        if (parser.Contains(nameof(WireMockServerSettings.Port)))
+        {
+            settings.Port = parser.GetIntValue(nameof(WireMockServerSettings.Port));
+        }
+        else if (settings.HostingScheme is null)
+        {
+            settings.Urls = parser.GetValues("Urls", new[] { "http://*:9091/" });
+        }
+    }
+
+    private static void ParseCertificateSettings(WireMockServerSettings settings, SimpleCommandLineParser parser)
+    {
         var certificateSettings = new WireMockCertificateSettings
         {
             X509StoreName = parser.GetStringValue("X509StoreName"),
@@ -145,7 +161,33 @@ public static class WireMockServerSettingsParser
         {
             settings.CertificateSettings = certificateSettings;
         }
+    }
 
-        return true;
+    private static void ParseWebProxyAddressSettings(ProxyAndRecordSettings settings, SimpleCommandLineParser parser)
+    {
+        string? proxyAddress = parser.GetStringValue("WebProxyAddress");
+        if (!string.IsNullOrEmpty(proxyAddress))
+        {
+            settings.WebProxySettings = new WebProxySettings
+            {
+                Address = proxyAddress!,
+                UserName = parser.GetStringValue("WebProxyUserName"),
+                Password = parser.GetStringValue("WebProxyPassword")
+            };
+        }
+    }
+
+    private static void ParseProxyUrlReplaceSettings(ProxyAndRecordSettings settings, SimpleCommandLineParser parser)
+    {
+        var proxyUrlReplaceOldValue = parser.GetStringValue("ProxyUrlReplaceOldValue");
+        var proxyUrlReplaceNewValue = parser.GetStringValue("ProxyUrlReplaceNewValue");
+        if (!string.IsNullOrEmpty(proxyUrlReplaceOldValue) && proxyUrlReplaceNewValue != null)
+        {
+            settings.ReplaceSettings = new ProxyUrlReplaceSettings
+            {
+                OldValue = proxyUrlReplaceOldValue!,
+                NewValue = proxyUrlReplaceNewValue!
+            };
+        }
     }
 }

src/WireMock.Net/Util/TinyMapperUtils.cs

@@ -12,9 +12,11 @@ internal sealed class TinyMapperUtils
     {
         TinyMapper.Bind<ProxyAndRecordSettings, ProxyAndRecordSettingsModel>();
         TinyMapper.Bind<WebProxySettings, WebProxySettingsModel>();
+        TinyMapper.Bind<ProxyUrlReplaceSettings, ProxyUrlReplaceSettingsModel>();
 
         TinyMapper.Bind<ProxyAndRecordSettingsModel, ProxyAndRecordSettings>();
         TinyMapper.Bind<WebProxySettingsModel, WebProxySettings>();
+        TinyMapper.Bind<ProxyUrlReplaceSettingsModel, ProxyUrlReplaceSettings>();
     }
 
     public ProxyAndRecordSettingsModel? Map(ProxyAndRecordSettings? instance)

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

@@ -570,6 +570,52 @@ public class WireMockServerProxyTests
         Check.That(matchers).Contains("name");
     }
 
+    [Fact]
+    public async Task WireMockServer_Proxy_Should_replace_old_path_value_with_new_path_value_in_replace_settings()
+    {
+        // Assign
+        var replaceSettings = new ProxyUrlReplaceSettings
+        {
+            OldValue = "value-to-replace",
+            NewValue = "new-value"
+        };
+        string path = $"/prx_{Guid.NewGuid()}";
+        var serverForProxyForwarding = WireMockServer.Start();
+        serverForProxyForwarding
+            .Given(Request.Create().WithPath($"/{replaceSettings.NewValue}{path}"))
+            .RespondWith(Response.Create());
+
+        var settings = new WireMockServerSettings
+        {
+            ProxyAndRecordSettings = new ProxyAndRecordSettings
+            {
+                Url = serverForProxyForwarding.Urls[0],
+                SaveMapping = true,
+                SaveMappingToFile = false,
+                ReplaceSettings = replaceSettings
+            }
+        };
+        var server = WireMockServer.Start(settings);
+        var defaultMapping = server.Mappings.First();
+
+        // Act
+        var requestMessage = new HttpRequestMessage
+        {
+            Method = HttpMethod.Post,
+            RequestUri = new Uri($"{server.Urls[0]}/{replaceSettings.OldValue}{path}"),
+            Content = new StringContent("stringContent")
+        };
+
+        var handler = new HttpClientHandler();
+        await new HttpClient(handler).SendAsync(requestMessage).ConfigureAwait(false);
+
+        // Assert
+        var mapping = serverForProxyForwarding.Mappings.FirstOrDefault(m => m.Guid != defaultMapping.Guid);
+        var score = mapping.RequestMatcher.GetMatchingScore(serverForProxyForwarding.LogEntries.First().RequestMessage,
+            new RequestMatchResult());
+        Check.That(score).IsEqualTo(1.0);
+    }
+
     [Fact]
     public async Task WireMockServer_Proxy_Should_preserve_content_header_in_proxied_request_with_empty_content()
     {