Fix WebSocket tests

Co-authored-by: Stef Heyenrath <Stef.Heyenrath@gmail.com>

CHANGELOG.md

@@ -1,3 +1,13 @@
+# 2.2.0 (30 March 2026)
+- [#1433](https://github.com/wiremock/WireMock.Net/pull/1433) - Add comments for ScenarioStateStore related code [refactor] contributed by [StefH](https://github.com/StefH)
+- [#1434](https://github.com/wiremock/WireMock.Net/pull/1434) - Upgrade Scriban.Signed [security] contributed by [StefH](https://github.com/StefH)
+
+# 2.1.0 (29 March 2026)
+- [#1425](https://github.com/wiremock/WireMock.Net/pull/1425) - Add helpers for query params fluent MappingModelBuilder [feature] contributed by [biltongza](https://github.com/biltongza)
+- [#1430](https://github.com/wiremock/WireMock.Net/pull/1430) - Add injectable IScenarioStateStore for distributed scenario state [feature] contributed by [m4tchl0ck](https://github.com/m4tchl0ck)
+- [#1431](https://github.com/wiremock/WireMock.Net/pull/1431) - Fix WireMockLogger implementation in dotnet-WireMock [bug] contributed by [StefH](https://github.com/StefH)
+- [#1432](https://github.com/wiremock/WireMock.Net/pull/1432) - Add WireMockAspNetCoreLogger to log Kestrel warnings/errors [feature] contributed by [StefH](https://github.com/StefH)
+
 # 2.0.0 (11 March 2026)
 - [#1359](https://github.com/wiremock/WireMock.Net/pull/1359) - Version 2.x contributed by [StefH](https://github.com/StefH)
 - [#1394](https://github.com/wiremock/WireMock.Net/pull/1394) - MappingSerializer (Newtonsoft or SystemText)-Json [feature] contributed by [StefH](https://github.com/StefH)
@@ -1356,11 +1366,11 @@
 - [#145](https://github.com/wiremock/WireMock.Net/pull/145) - Cancellation token not passed to server instance in .NET Core 2 [bug] contributed by [Bob11327](https://github.com/Bob11327)
 
 # 1.0.3.18 (25 May 2018)
-- [#142](https://github.com/wiremock/WireMock.Net/pull/142) - Allow all headers to be set as Response headers contributed by [StefH](https://github.com/StefH)
+- [#142](https://github.com/wiremock/WireMock.Net/pull/142) - Allow all headers to be set as Response headers [bug] contributed by [StefH](https://github.com/StefH)
 - [#122](https://github.com/wiremock/WireMock.Net/issues/122) - WireMock.Net not responding in unit tests - same works in console application
 - [#126](https://github.com/wiremock/WireMock.Net/issues/126) - Question: UsingHead always returns 0 for Content-Length header even when explicitly specified
 - [#132](https://github.com/wiremock/WireMock.Net/issues/132) - LogEntries not being recorded on subsequent tests
-- [#136](https://github.com/wiremock/WireMock.Net/issues/136) - Question: Does the WireMock send Content-Length response header
+- [#136](https://github.com/wiremock/WireMock.Net/issues/136) - Question: Does the WireMock send Content-Length response header [bug]
 - [#137](https://github.com/wiremock/WireMock.Net/issues/137) - Question: How to specify Transfer-Encoding response header?
 - [#139](https://github.com/wiremock/WireMock.Net/issues/139) - Wiki link https://github.com/StefH/WireMock.Net/wiki/Record-(via-proxy)-and-Save is dead
 

Directory.Build.props

@@ -4,7 +4,7 @@
     </PropertyGroup>
 
     <PropertyGroup>
-        <VersionPrefix>2.0.0</VersionPrefix>
+        <VersionPrefix>2.2.0</VersionPrefix>
         <PackageIcon>WireMock.Net-Logo.png</PackageIcon>
         <PackageProjectUrl>https://github.com/wiremock/WireMock.Net</PackageProjectUrl>
         <PackageLicenseExpression>Apache-2.0</PackageLicenseExpression>

Generate-ReleaseNotes.cmd

@@ -1,7 +1,7 @@
 rem https://github.com/StefH/GitHubReleaseNotes
 
-SET version=2.0.0
+SET version=2.2.0
 
 GitHubReleaseNotes --output CHANGELOG.md --skip-empty-releases --exclude-labels wontfix test question invalid doc duplicate example environment --version %version% --token %GH_TOKEN%
 
-GitHubReleaseNotes --output PackageReleaseNotes.txt --skip-empty-releases --exclude-labels test question invalid doc duplicate example environment --template PackageReleaseNotes.template --version %version% --token %GH_TOKEN%
+GitHubReleaseNotes --output PackageReleaseNotes.txt --skip-empty-releases --exclude-labels wontfix test question invalid doc duplicate example environment --template PackageReleaseNotes.template --version %version% --token %GH_TOKEN%

PackageReleaseNotes.txt

@@ -1,8 +1,5 @@
-# 2.0.0 (11 March 2026)
+# 2.2.0 (30 March 2026)
-- #1359 Version 2.x
+- #1433 Add comments for ScenarioStateStore related code [refactor]
-- #1394 MappingSerializer (Newtonsoft or SystemText)-Json [feature]
+- #1434 Upgrade Scriban.Signed [security]
-- #1341 Configurable JSON serialization support (Newtonsoft.Json vs System.Text.Json) [feature]
-- #1422 WireMock.Net seems to be incompatible with Microsoft.Owin.Security.Interop [bug]
-- #1424 WireMock.Net.FluentAssertions is incompatible with WireMock.Net.Aspire [feature]
 
 The full release notes can be found here: https://github.com/wiremock/WireMock.Net/blob/master/CHANGELOG.md

README.md

@@ -71,6 +71,7 @@ A C# .NET version based on [mock4net](https://github.com/alexvictoor/mock4net) w
 |   **WireMock.Net.OpenTelemetry** | [![NuGet Badge WireMock.Net.OpenTelemetry](https://img.shields.io/nuget/v/WireMock.Net.OpenTelemetry)](https://www.nuget.org/packages/WireMock.Net.ProtoBuf) | [![MyGet Badge WireMock.Net.OpenTelemetry](https://img.shields.io/myget/wiremock-net/vpre/WireMock.Net.OpenTelemetry?includePreReleases=true&label=MyGet)](https://www.myget.org/feed/wiremock-net/package/nuget/WireMock.Net.OpenTelemetry)
 | | | |
 |   **WireMock.Net.RestClient** | [![NuGet Badge WireMock.Net.RestClient](https://img.shields.io/nuget/v/WireMock.Net.RestClient)](https://www.nuget.org/packages/WireMock.Net.RestClient) | [![MyGet Badge WireMock.Net.RestClient](https://img.shields.io/myget/wiremock-net/vpre/WireMock.Net.RestClient?includePreReleases=true&label=MyGet)](https://www.myget.org/feed/wiremock-net/package/nuget/WireMock.Net.RestClient)
+|   **WireMock.Net.RestClient.AwesomeAssertions** | [![NuGet Badge WireMock.Net.RestClient.AwesomeAssertions](https://img.shields.io/nuget/v/WireMock.Net.RestClient.AwesomeAssertions)](https://www.nuget.org/packages/WireMock.Net.RestClient.AwesomeAssertions) | [![MyGet Badge WireMock.Net.RestClient.AwesomeAssertions](https://img.shields.io/myget/wiremock-net/vpre/WireMock.Net.RestClient.AwesomeAssertions?includePreReleases=true&label=MyGet)](https://www.myget.org/feed/wiremock-net/package/nuget/WireMock.Net.RestClient.AwesomeAssertions)
 |   **WireMock.Org.RestClient** | [![NuGet Badge WireMock.Org.RestClient](https://img.shields.io/nuget/v/WireMock.Org.RestClient)](https://www.nuget.org/packages/WireMock.Org.RestClient) | [![MyGet Badge WireMock.Org.RestClient](https://img.shields.io/myget/wiremock-net/vpre/WireMock.Org.RestClient?includePreReleases=true&label=MyGet)](https://www.myget.org/feed/wiremock-net/package/nuget/WireMock.Org.RestClient)
 
 <br />

examples/WireMock.Net.Client/Program.cs

@@ -82,6 +82,51 @@ class Program
             )
         );
 
+        mappingBuilder.Given(m => m
+            .WithRequest(req => req
+                .WithPath("/testRequestWithQueryParams")
+                .UsingGet()
+                .WithParams(p => p.WithParam("param1", pb => pb.WithExactMatcher("value1")))
+            ).WithResponse(rsp => rsp
+                .WithHeaders(h => h.Add("Content-Type", "application/json"))
+                .WithStatusCode(200)
+                .WithBodyAsJson(new
+                {
+                    status = "ok"
+                }, true)
+            )
+        );
+
+        mappingBuilder.Given(m => m
+            .WithRequest(req => req
+                .WithPath("/testRequestWithHeaders")
+                .UsingGet()
+                .WithHeaders(h => h.WithHeader("Accept", hb => hb.WithExactMatcher("application/json")))
+            ).WithResponse(rsp => rsp
+                .WithHeaders(h => h.Add("Content-Type", "application/json"))
+                .WithStatusCode(200)
+                .WithBodyAsJson(new
+                {
+                    status = "ok"
+                }, true)
+            )
+        );
+
+        mappingBuilder.Given(m => m
+            .WithRequest(req => req
+                .WithPath("/testRequestWithCookie")
+                .UsingGet()
+                .WithCookies(c => c.WithCookie("cookie1", cb => cb.WithExactMatcher("cookievalue1")))
+            ).WithResponse(rsp => rsp
+                .WithHeaders(h => h.Add("Content-Type", "application/json"))
+                .WithStatusCode(200)
+                .WithBodyAsJson(new
+                {
+                    status = "ok"
+                }, true)
+            )
+        );
+
         var result = await mappingBuilder.BuildAndPostAsync().ConfigureAwait(false);
         Console.WriteLine($"result = {JsonConvert.SerializeObject(result)}");
 

examples/WireMock.Net.Console.NET8/MainApp.cs

@@ -8,6 +8,7 @@ using System.Linq;
 using System.Net;
 using System.Threading.Tasks;
 using Newtonsoft.Json;
+using SharpYaml.Model;
 using WireMock.Logging;
 using WireMock.Matchers;
 using WireMock.Models;
@@ -288,7 +289,24 @@ namespace WireMock.Net.ConsoleApplication
 
             var todos = new Dictionary<int, Todo>();
 
-            var server = WireMockServer.Start();
+            var server = WireMockServer.Start(new WireMockServerSettings
+            {
+                Logger = new WireMockConsoleLogger(),
+
+                Port = 9091
+            });
+
+            server
+               .WhenRequest(r => r
+                   .WithPath("/Content-Length")
+                   .UsingAnyMethod()
+               )
+               .ThenRespondWith(r => r
+                   .WithStatusCode(HttpStatusCode.OK)
+                   .WithHeader("Content-Length", "42")
+               );
+
+            System.Console.ReadLine();
 
             //server
             //    .Given(Request.Create()

examples/WireMock.Net.WebApplication.IIS/App.cs

@@ -1,29 +1,18 @@
 // Copyright © WireMock.Net
 
-using Microsoft.Extensions.Hosting;
-using System.Threading;
-using System.Threading.Tasks;
-
 namespace WireMock.Net.WebApplication;
 
-public class App : IHostedService
+public class App(IWireMockService service) : IHostedService
 {
-    private readonly IWireMockService _service;
-        
-    public App(IWireMockService service)
-    {
-        _service = service;
-    }
-
     public Task StartAsync(CancellationToken cancellationToken)
     {
-        _service.Start();
+        service.Start();
         return Task.CompletedTask;
     }
 
     public Task StopAsync(CancellationToken cancellationToken)
     {
-        _service.Stop();
+        service.Stop();
         return Task.CompletedTask;
     }
 }

examples/WireMock.Net.WebApplication.IIS/Program.cs

@@ -1,9 +1,5 @@
 // Copyright © WireMock.Net
 
-using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Hosting;
-using Microsoft.Extensions.Logging;
 using WireMock.Settings;
 
 namespace WireMock.Net.WebApplication;

examples/WireMock.Net.WebApplication.IIS/WireMock.Net.WebApplication.IIS.csproj

@@ -15,7 +15,6 @@
     </ItemGroup>
 
     <ItemGroup>
-        <ProjectReference Include="..\..\src\WireMock.Net.Abstractions\WireMock.Net.Abstractions.csproj" />
         <ProjectReference Include="..\..\src\WireMock.Net\WireMock.Net.csproj" />
     </ItemGroup>
 

examples/WireMock.Net.WebApplication.IIS/WireMockService.cs

@@ -1,7 +1,5 @@
 // Copyright © WireMock.Net
 
-using System;
-using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Newtonsoft.Json;
 using WireMock.Admin.Requests;

examples/WireMock.Net.WebApplication.IIS/appsettings.json

@@ -15,7 +15,7 @@
     "WireMockServerSettings": {
         "StartAdminInterface": true,
         "Urls": [
-            "http://localhost"
+            "http://localhost:0"
         ]
     }
 }

examples/WireMock.Net.WebApplication.IIS/web.config

@@ -1,12 +1,17 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
-  <!--
+    <!--
     Configure your application settings in appsettings.json. Learn more at http://go.microsoft.com/fwlink/?LinkId=786380
-  -->
+    -->
-  <system.webServer>
+    <system.webServer>
-    <handlers>
+        <handlers>
-      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
+            <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
-    </handlers>
+        </handlers>
-    <aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" forwardWindowsAuthToken="false" />
+        <httpProtocol>
-  </system.webServer>
+            <customHeaders>
+                <add name="X-Frame-Options" value="SAMEORIGIN" />
+            </customHeaders>
+        </httpProtocol>
+        <aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" forwardWindowsAuthToken="false" />
+    </system.webServer>
 </configuration>

src/WireMock.Net.Abstractions/BuilderExtensions/ArrayMatcherModelBuilder.cs

@@ -0,0 +1,39 @@
+// Copyright © WireMock.Net
+
+namespace WireMock.Admin.Mappings;
+
+public partial class ArrayMatcherModelBuilder
+{
+    public ArrayMatcherModelBuilder WithExactMatcher(object pattern, bool rejectOnMatch = false, bool ignoreCase = false)
+    {
+        return WithMatcher("ExactMatcher", pattern, rejectOnMatch, ignoreCase);
+    }
+
+    public ArrayMatcherModelBuilder WithWildcardMatcher(object pattern, bool rejectOnMatch = false, bool ignoreCase = false)
+    {
+        return WithMatcher("WildcardMatcher", pattern, rejectOnMatch, ignoreCase);
+    }
+
+    public ArrayMatcherModelBuilder WithRegexMatcher(object pattern, bool rejectOnMatch = false, bool ignoreCase = false)
+    {
+        return WithMatcher("RegexMatcher", pattern, rejectOnMatch, ignoreCase);
+    }
+
+    public ArrayMatcherModelBuilder WithNotNullOrEmptyMatcher(bool rejectOnMatch = false)
+    {
+        return Add(mb => mb
+            .WithName("NotNullOrEmptyMatcher")
+            .WithRejectOnMatch(rejectOnMatch)
+        );
+    }
+
+    private ArrayMatcherModelBuilder WithMatcher(string name, object pattern, bool rejectOnMatch, bool ignoreCase = false)
+    {
+        return Add(mb => mb
+            .WithName(name)
+            .WithPattern(pattern)
+            .WithRejectOnMatch(rejectOnMatch)
+            .WithIgnoreCase(ignoreCase)
+        );
+    }
+}

src/WireMock.Net.Abstractions/BuilderExtensions/IListCookieModelBuilder.cs

@@ -0,0 +1,19 @@
+// Copyright © WireMock.Net
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace WireMock.Admin.Mappings;
+
+public partial class IListCookieModelBuilder
+{
+    public IListCookieModelBuilder WithCookie(string name, Action<IListMatcherModelBuilder> action, bool rejectOnMatch = false)
+    {
+        return Add(cookieBuilder => cookieBuilder
+            .WithName(name)
+            .WithRejectOnMatch(rejectOnMatch)
+            .WithMatchers(matchersBuilder => action(matchersBuilder))
+        );
+    }
+}

src/WireMock.Net.Abstractions/BuilderExtensions/IListHeaderModelBuilder.cs

@@ -0,0 +1,19 @@
+// Copyright © WireMock.Net
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace WireMock.Admin.Mappings;
+
+public partial class IListHeaderModelBuilder
+{
+    public IListHeaderModelBuilder WithHeader(string name, Action<IListMatcherModelBuilder> action, bool rejectOnMatch = false)
+    {
+        return Add(headerBuilder => headerBuilder
+            .WithName(name)
+            .WithRejectOnMatch(rejectOnMatch)
+            .WithMatchers(matchersBuilder => action(matchersBuilder))
+        );
+    }
+}

src/WireMock.Net.Abstractions/BuilderExtensions/IListMatcherModelBuilder.cs

@@ -0,0 +1,39 @@
+// Copyright © WireMock.Net
+
+namespace WireMock.Admin.Mappings;
+
+public partial class IListMatcherModelBuilder
+{
+    public IListMatcherModelBuilder WithExactMatcher(object pattern, bool rejectOnMatch = false, bool ignoreCase = false)
+    {
+        return WithMatcher("ExactMatcher", pattern, rejectOnMatch, ignoreCase);
+    }
+
+    public IListMatcherModelBuilder WithWildcardMatcher(object pattern, bool rejectOnMatch = false, bool ignoreCase = false)
+    {
+        return WithMatcher("WildcardMatcher", pattern, rejectOnMatch, ignoreCase);
+    }
+
+    public IListMatcherModelBuilder WithRegexMatcher(object pattern, bool rejectOnMatch = false, bool ignoreCase = false)
+    {
+        return WithMatcher("RegexMatcher", pattern, rejectOnMatch, ignoreCase);
+    }
+
+    public IListMatcherModelBuilder WithNotNullOrEmptyMatcher(bool rejectOnMatch = false)
+    {
+        return Add(mb => mb
+            .WithName("NotNullOrEmptyMatcher")
+            .WithRejectOnMatch(rejectOnMatch)
+        );
+    }
+
+    private IListMatcherModelBuilder WithMatcher(string name, object pattern, bool rejectOnMatch, bool ignoreCase = false)
+    {
+        return Add(mb => mb
+            .WithName(name)
+            .WithPattern(pattern)
+            .WithRejectOnMatch(rejectOnMatch)
+            .WithIgnoreCase(ignoreCase)
+        );
+    }
+}

src/WireMock.Net.Abstractions/BuilderExtensions/IListParamModelBuilder.cs

@@ -0,0 +1,17 @@
+// Copyright © WireMock.Net
+
+using System;
+
+namespace WireMock.Admin.Mappings;
+
+public partial class IListParamModelBuilder
+{
+    public IListParamModelBuilder WithParam(string name, Action<ArrayMatcherModelBuilder> action, bool rejectOnMatch = false)
+    {
+        return Add(paramBuilder => paramBuilder
+            .WithName(name)
+            .WithRejectOnMatch(rejectOnMatch)
+            .WithMatchers(matchersBuilder => action(matchersBuilder))
+        );
+    }
+}

src/WireMock.Net.Abstractions/Handlers/IScenarioStateStore.cs

@@ -0,0 +1,24 @@
+// Copyright © WireMock.Net
+
+using System.Diagnostics.CodeAnalysis;
+
+namespace WireMock.Handlers;
+
+public interface IScenarioStateStore
+{
+    bool TryGet(string name, [NotNullWhen(true)] out ScenarioState? state);
+
+    IReadOnlyList<ScenarioState> GetAll();
+
+    bool ContainsKey(string name);
+
+    bool TryAdd(string name, ScenarioState scenarioState);
+
+    ScenarioState AddOrUpdate(string name, Func<string, ScenarioState> addFactory, Func<string, ScenarioState, ScenarioState> updateFactory);
+
+    ScenarioState? Update(string name, Action<ScenarioState> updateAction);
+
+    bool TryRemove(string name);
+
+    void Clear();
+}

src/WireMock.Net.Abstractions/Matchers/Request/MatchDetail.cs

@@ -10,7 +10,7 @@ public class MatchDetail
     /// <summary>
     /// Gets or sets the type of the matcher.
     /// </summary>
-    public required Type MatcherType { get; set; }
+    public required string MatcherType { get; set; }
 
     /// <summary>
     /// Gets or sets the type of the matcher.

src/WireMock.Net.Abstractions/ScenarioState.cs

@@ -31,4 +31,4 @@ public class ScenarioState
     /// Gets or sets the state counter.
     /// </summary>
     public int Counter { get; set; }
-}
+}

src/WireMock.Net.Abstractions/Server/IWireMockServer.cs

@@ -33,12 +33,6 @@ public interface IWireMockServer : IDisposable
     /// </summary>
     IReadOnlyList<MappingModel> MappingModels { get; }
 
-    // <summary>
-    // Gets the mappings.
-    // </summary>
-    //[PublicAPI]
-    //IEnumerable<IMapping> Mappings { get; }
-
     /// <summary>
     /// Gets the ports.
     /// </summary>
@@ -69,8 +63,6 @@ public interface IWireMockServer : IDisposable
     /// </summary>
     string? Provider { get; }
 
-    //ConcurrentDictionary<string, ScenarioState> Scenarios { get; }
-
     /// <summary>
     /// Occurs when [log entries changed].
     /// </summary>
@@ -115,8 +107,6 @@ public interface IWireMockServer : IDisposable
     /// <returns>The <see cref="IReadOnlyList{ILogEntry}"/>.</returns>
     IReadOnlyList<ILogEntry> FindLogEntries(params IRequestMatcher[] matchers);
 
-    // IRespondWithAProvider Given(IRequestMatcher requestMatcher, bool saveToFile = false);
-
     /// <summary>
     /// Reads a static mapping file and adds or updates a single mapping.
     /// 

src/WireMock.Net.Minimal/Handlers/FileBasedScenarioStateStore.cs

@@ -0,0 +1,145 @@
+// Copyright © WireMock.Net
+
+using System.Collections.Concurrent;
+using System.Diagnostics.CodeAnalysis;
+using Newtonsoft.Json;
+using Stef.Validation;
+
+namespace WireMock.Handlers;
+
+/// <summary>
+/// Provides a file-based implementation of <see cref="IScenarioStateStore" /> that persists scenario states to disk and allows concurrent access.
+/// </summary>
+public class FileBasedScenarioStateStore : IScenarioStateStore
+{
+    private readonly ConcurrentDictionary<string, ScenarioState> _scenarios = new(StringComparer.OrdinalIgnoreCase);
+    private readonly string _scenariosFolder;
+    private readonly object _lock = new();
+
+    /// <summary>
+    /// Initializes a new instance of the FileBasedScenarioStateStore class using the specified root folder as the base directory for scenario state storage.
+    /// </summary>
+    /// <param name="rootFolder">The root directory under which scenario state data will be stored. Must be a valid file system path.</param>
+    public FileBasedScenarioStateStore(string rootFolder)
+    {
+        Guard.NotNullOrEmpty(rootFolder);
+
+        _scenariosFolder = Path.Combine(rootFolder, "__admin", "scenarios");
+        Directory.CreateDirectory(_scenariosFolder);
+        LoadScenariosFromDisk();
+    }
+
+    /// <inheritdoc />
+    public bool TryGet(string name, [NotNullWhen(true)] out ScenarioState? state)
+    {
+        return _scenarios.TryGetValue(name, out state);
+    }
+
+    /// <inheritdoc />
+    public IReadOnlyList<ScenarioState> GetAll()
+    {
+        return _scenarios.Values.ToArray();
+    }
+
+    /// <inheritdoc />
+    public bool ContainsKey(string name)
+    {
+        return _scenarios.ContainsKey(name);
+    }
+
+    /// <inheritdoc />
+    public bool TryAdd(string name, ScenarioState scenarioState)
+    {
+        if (_scenarios.TryAdd(name, scenarioState))
+        {
+            WriteScenarioToFile(name, scenarioState);
+            return true;
+        }
+
+        return false;
+    }
+
+    /// <inheritdoc />
+    public ScenarioState AddOrUpdate(string name, Func<string, ScenarioState> addFactory, Func<string, ScenarioState, ScenarioState> updateFactory)
+    {
+        lock (_lock)
+        {
+            var result = _scenarios.AddOrUpdate(name, addFactory, updateFactory);
+            WriteScenarioToFile(name, result);
+            return result;
+        }
+    }
+
+    /// <inheritdoc />
+    public ScenarioState? Update(string name, Action<ScenarioState> updateAction)
+    {
+        lock (_lock)
+        {
+            if (_scenarios.TryGetValue(name, out var state))
+            {
+                updateAction(state);
+                WriteScenarioToFile(name, state);
+                return state;
+            }
+
+            return null;
+        }
+    }
+
+    /// <inheritdoc />
+    public bool TryRemove(string name)
+    {
+        if (_scenarios.TryRemove(name, out _))
+        {
+            DeleteScenarioFile(name);
+            return true;
+        }
+
+        return false;
+    }
+
+    /// <inheritdoc />
+    public void Clear()
+    {
+        _scenarios.Clear();
+
+        foreach (var file in Directory.GetFiles(_scenariosFolder, "*.json"))
+        {
+            File.Delete(file);
+        }
+    }
+
+    private string GetScenarioFilePath(string name)
+    {
+        var sanitized = string.Concat(name.Select(c => Path.GetInvalidFileNameChars().Contains(c) ? '_' : c));
+        return Path.Combine(_scenariosFolder, sanitized + ".json");
+    }
+
+    private void WriteScenarioToFile(string name, ScenarioState state)
+    {
+        var json = JsonConvert.SerializeObject(state, Formatting.Indented);
+        File.WriteAllText(GetScenarioFilePath(name), json);
+    }
+
+    private void DeleteScenarioFile(string name)
+    {
+        var path = GetScenarioFilePath(name);
+        if (File.Exists(path))
+        {
+            File.Delete(path);
+        }
+    }
+
+    private void LoadScenariosFromDisk()
+    {
+        foreach (var file in Directory.GetFiles(_scenariosFolder, "*.json"))
+        {
+            var json = File.ReadAllText(file);
+            var state = JsonConvert.DeserializeObject<ScenarioState>(json);
+            if (state != null)
+            {
+                _scenarios.TryAdd(state.Name, state);
+            }
+        }
+    }
+}

src/WireMock.Net.Minimal/Logging/WireMockAspNetCoreLogger.cs

@@ -0,0 +1,38 @@
+// Copyright © WireMock.Net
+
+using Microsoft.Extensions.Logging;
+
+namespace WireMock.Logging;
+
+internal sealed class WireMockAspNetCoreLogger(IWireMockLogger logger, string categoryName) : ILogger
+{
+    public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+
+    public bool IsEnabled(LogLevel logLevel) => logLevel >= LogLevel.Warning;
+
+    public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
+    {
+        if (!IsEnabled(logLevel))
+        {
+            return;
+        }
+
+        var message = formatter(state, exception);
+
+        if (exception != null)
+        {
+            message = $"{message} | Exception: {exception}";
+        }
+
+        switch (logLevel)
+        {
+            case LogLevel.Warning:
+                logger.Warn("[{0}] {1}", categoryName, message);
+                break;
+
+            default:
+                logger.Error("[{0}] {1}", categoryName, message);
+                break;
+        }
+    }
+}

src/WireMock.Net.Minimal/Logging/WireMockAspNetCoreLoggerProvider.cs

@@ -0,0 +1,19 @@
+// Copyright © WireMock.Net
+
+using Microsoft.Extensions.Logging;
+
+namespace WireMock.Logging;
+
+internal sealed class WireMockAspNetCoreLoggerProvider : ILoggerProvider
+{
+    private readonly IWireMockLogger _logger;
+
+    public WireMockAspNetCoreLoggerProvider(IWireMockLogger logger)
+    {
+        _logger = logger;
+    }
+
+    public ILogger CreateLogger(string categoryName) => new WireMockAspNetCoreLogger(_logger, categoryName);
+
+    public void Dispose() { }
+}

src/WireMock.Net.Minimal/Matchers/Request/RequestMatchResult.cs

@@ -1,7 +1,5 @@
 // Copyright © WireMock.Net
 
-using System.Linq;
-
 namespace WireMock.Matchers.Request;
 
 /// <summary>
@@ -30,7 +28,7 @@ public class RequestMatchResult : IRequestMatchResult
         return AddMatchDetail(new MatchDetail
         {
             Name = matcherType.Name.Replace("RequestMessage", string.Empty),
-            MatcherType = matcherType,
+            MatcherType = matcherType.Name,
             Score = score,
             Exception = exception
         });

src/WireMock.Net.Minimal/Owin/AspNetCoreSelfHost.cs

@@ -1,9 +1,9 @@
 // Copyright © WireMock.Net
 
-using System.Linq;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
 using Stef.Validation;
 using WireMock.Logging;
 using WireMock.Owin.Mappers;
@@ -57,6 +57,12 @@ internal partial class AspNetCoreSelfHost
         _host = builder
             .UseSetting("suppressStatusMessages", "True") // https://andrewlock.net/suppressing-the-startup-and-shutdown-messages-in-asp-net-core/
             .ConfigureAppConfigurationUsingEnvironmentVariables()
+            .ConfigureLogging(logging =>
+            {
+                logging.ClearProviders();
+                logging.AddProvider(new WireMockAspNetCoreLoggerProvider(_logger));
+                logging.SetMinimumLevel(LogLevel.Warning);
+            })
             .ConfigureServices(services =>
             {
                 services.AddSingleton(_wireMockMiddlewareOptions);
@@ -169,10 +175,10 @@ internal partial class AspNetCoreSelfHost
 
             return _host.RunAsync(token);
         }
-        catch (Exception e)
+        catch (Exception ex)
         {
-            RunningException = e;
+            RunningException = ex;
-            _logger.Error(e.ToString());
+            _logger.Error("Error while RunAsync", ex);
 
             IsStarted = false;
 

src/WireMock.Net.Minimal/Owin/IWireMockMiddlewareOptions.cs

@@ -27,7 +27,7 @@ internal interface IWireMockMiddlewareOptions
 
     ConcurrentDictionary<Guid, IMapping> Mappings { get; }
 
-    ConcurrentDictionary<string, ScenarioState> Scenarios { get; }
+    IScenarioStateStore ScenarioStateStore { get; set; }
 
     ConcurrentObservableCollection<LogEntry> LogEntries { get; }
 

src/WireMock.Net.Minimal/Owin/Mappers/OwinResponseMapper.cs

@@ -1,9 +1,7 @@
 // Copyright © WireMock.Net
 
 using System.Globalization;
-using System.Linq;
 using System.Net;
-using System.Reflection;
 using System.Text;
 using Microsoft.AspNetCore.Http;
 using Newtonsoft.Json;
@@ -88,19 +86,15 @@ namespace WireMock.Owin.Mappers
                     break;
             }
 
-            var statusCodeType = responseMessage.StatusCode?.GetType();
+            if (responseMessage.StatusCode is HttpStatusCode or int)
-            if (statusCodeType != null)
             {
-                if (statusCodeType == typeof(int) || statusCodeType == typeof(int?) || statusCodeType.GetTypeInfo().IsEnum)
+                response.StatusCode = MapStatusCode((int) responseMessage.StatusCode);
-                {
+            }
-                    response.StatusCode = MapStatusCode((int)responseMessage.StatusCode!);
+            else if (responseMessage.StatusCode is string statusCodeAsString)
-                }
+            {
-                else if (statusCodeType == typeof(string))
+                // Note: this case will also match on null
-                {
+                _ = int.TryParse(statusCodeAsString, out var statusCodeTypeAsInt);
-                    // Note: this case will also match on null
+                response.StatusCode = MapStatusCode(statusCodeTypeAsInt);
-                    int.TryParse(responseMessage.StatusCode as string, out var statusCodeTypeAsInt);
-                    response.StatusCode = MapStatusCode(statusCodeTypeAsInt);
-                }
             }
 
             SetResponseHeaders(responseMessage, bytes != null, response);

src/WireMock.Net.Minimal/Owin/MappingMatcher.cs

@@ -89,14 +89,13 @@ internal class MappingMatcher(IWireMockMiddlewareOptions options, IRandomizerDou
 
     private string? GetNextState(IMapping mapping)
     {
-        // If the mapping does not have a scenario or _options.Scenarios does not contain this scenario from the mapping,
+        // If the mapping does not have a scenario or the store does not contain this scenario,
         // just return null to indicate that there is no next state.
-        if (mapping.Scenario == null || !_options.Scenarios.ContainsKey(mapping.Scenario))
+        if (mapping.Scenario == null)
         {
             return null;
         }
 
-        // Else just return the next state
+        return _options.ScenarioStateStore.TryGet(mapping.Scenario, out var state) ? state.NextState : null;
-        return _options.Scenarios[mapping.Scenario].NextState;
     }
 }

src/WireMock.Net.Minimal/Owin/WireMockMiddleware.cs

@@ -81,9 +81,9 @@ internal class WireMockMiddleware(
                 }
 
                 // Set scenario start
-                if (!options.Scenarios.ContainsKey(mapping.Scenario) && mapping.IsStartState)
+                if (!options.ScenarioStateStore.ContainsKey(mapping.Scenario) && mapping.IsStartState)
                 {
-                    options.Scenarios.TryAdd(mapping.Scenario, new ScenarioState
+                    options.ScenarioStateStore.TryAdd(mapping.Scenario, new ScenarioState
                     {
                         Name = mapping.Scenario
                     });
@@ -122,6 +122,14 @@ internal class WireMockMiddleware(
                 }
             }
 
+            // Transition scenario state immediately after matching, before any delay (global or
+            // per-mapping) so that concurrent retries arriving during a delay period see the
+            // updated state and match the correct next mapping instead of re-matching this one.
+            if (targetMapping.Scenario != null)
+            {
+                UpdateScenarioState(targetMapping);
+            }
+
             if (!targetMapping.IsAdminInterface && options.RequestProcessingDelay > TimeSpan.Zero)
             {
                 await Task.Delay(options.RequestProcessingDelay.Value).ConfigureAwait(false);
@@ -147,11 +155,6 @@ internal class WireMockMiddleware(
                 }
             }
 
-            if (targetMapping.Scenario != null)
-            {
-                UpdateScenarioState(targetMapping);
-            }
-
             if (!targetMapping.IsAdminInterface && targetMapping.Webhooks?.Length > 0)
             {
                 await SendToWebhooksAsync(targetMapping, request, response).ConfigureAwait(false);
@@ -233,20 +236,21 @@ internal class WireMockMiddleware(
 
     private void UpdateScenarioState(IMapping mapping)
     {
-        var scenario = options.Scenarios[mapping.Scenario!];
+        options.ScenarioStateStore.Update(mapping.Scenario!, scenario =>
-
-        // Increase the number of times this state has been executed
-        scenario.Counter++;
-
-        // Only if the number of times this state is executed equals the required StateTimes, proceed to next state and reset the counter to 0
-        if (scenario.Counter == (mapping.TimesInSameState ?? 1))
         {
-            scenario.NextState = mapping.NextState;
+            // Increase the number of times this state has been executed
-            scenario.Counter = 0;
+            scenario.Counter++;
-        }
 
-        // Else just update Started and Finished
+            // Only if the number of times this state is executed equals the required StateTimes, proceed to next state and reset the counter to 0
-        scenario.Started = true;
+            if (scenario.Counter == (mapping.TimesInSameState ?? 1))
-        scenario.Finished = mapping.NextState == null;
+            {
+                scenario.NextState = mapping.NextState;
+                scenario.Counter = 0;
+            }
+
+            // Else just update Started and Finished
+            scenario.Started = true;
+            scenario.Finished = mapping.NextState == null;
+        });
     }
-}
+}

src/WireMock.Net.Minimal/Owin/WireMockMiddlewareOptions.cs

@@ -27,7 +27,7 @@ internal class WireMockMiddlewareOptions : IWireMockMiddlewareOptions
 
     public ConcurrentDictionary<Guid, IMapping> Mappings { get; } = new ConcurrentDictionary<Guid, IMapping>();
 
-    public ConcurrentDictionary<string, ScenarioState> Scenarios { get; } = new(StringComparer.OrdinalIgnoreCase);
+    public IScenarioStateStore ScenarioStateStore { get; set; } = new InMemoryScenarioStateStore();
 
     public ConcurrentObservableCollection<LogEntry> LogEntries { get; } = new();
 

src/WireMock.Net.Minimal/Owin/WireMockMiddlewareOptionsHelper.cs

@@ -27,6 +27,7 @@ internal static class WireMockMiddlewareOptionsHelper
         options.FileSystemHandler = settings.FileSystemHandler;
         options.HandleRequestsSynchronously = settings.HandleRequestsSynchronously;
         options.Logger = settings.Logger;
+        options.ScenarioStateStore = settings.ScenarioStateStore;
         options.MaxRequestLogCount = settings.MaxRequestLogCount;
         options.PostWireMockMiddlewareInit = settings.PostWireMockMiddlewareInit;
         options.PreWireMockMiddlewareInit = settings.PreWireMockMiddlewareInit;

src/WireMock.Net.Minimal/Server/WireMockServer.Admin.cs

@@ -672,7 +672,7 @@ public partial class WireMockServer
     #region Scenarios
     private IResponseMessage ScenariosGet(HttpContext _, IRequestMessage requestMessage)
     {
-        var scenariosStates = Scenarios.Values.Select(s => new ScenarioStateModel
+        var scenariosStates = Scenarios.Select(s => new ScenarioStateModel
         {
             Name = s.Name,
             NextState = s.NextState,
@@ -705,7 +705,7 @@ public partial class WireMockServer
     private IResponseMessage ScenariosSetState(HttpContext _, IRequestMessage requestMessage)
     {
         var name = Enumerable.Reverse(requestMessage.Path.Split('/')).Skip(1).First();
-        if (!_options.Scenarios.ContainsKey(name))
+        if (!_options.ScenarioStateStore.ContainsKey(name))
         {
             ResponseMessageBuilder.Create(HttpStatusCode.NotFound, $"No scenario found by name '{name}'.");
         }

src/WireMock.Net.Minimal/Transformers/Scriban/WireMockListAccessor.cs

@@ -19,7 +19,7 @@ internal class WireMockListAccessor : IListAccessor, IObjectAccessor
         return target?.ToString() ?? string.Empty;
     }
 
-    public void SetValue(TemplateContext context, SourceSpan span, object target, int index, object value)
+    public void SetValue(TemplateContext context, SourceSpan span, object target, int index, object? value)
     {
         throw new NotImplementedException();
     }
@@ -46,7 +46,7 @@ internal class WireMockListAccessor : IListAccessor, IObjectAccessor
         throw new NotImplementedException();
     }
 
-    public bool TrySetValue(TemplateContext context, SourceSpan span, object target, string member, object value)
+    public bool TrySetValue(TemplateContext context, SourceSpan span, object target, string member, object? value)
     {
         throw new NotImplementedException();
     }
@@ -56,7 +56,7 @@ internal class WireMockListAccessor : IListAccessor, IObjectAccessor
         throw new NotImplementedException();
     }
 
-    public bool TrySetItem(TemplateContext context, SourceSpan span, object target, object index, object value)
+    public bool TrySetItem(TemplateContext context, SourceSpan span, object target, object index, object? value)
     {
         throw new NotImplementedException();
     }

src/WireMock.Net.Minimal/Transformers/Scriban/WireMockTemplateContext.cs

@@ -8,9 +8,9 @@ namespace WireMock.Transformers.Scriban;
 
 internal class WireMockTemplateContext : TemplateContext
 {
-    protected override IObjectAccessor GetMemberAccessorImpl(object target)
+    protected override IObjectAccessor? GetMemberAccessorImpl(object target)
     {
-        return target?.GetType().GetGenericTypeDefinition() == typeof(WireMockList<>) ?
+        return target.GetType().GetGenericTypeDefinition() == typeof(WireMockList<>) ?
             new WireMockListAccessor() :
             base.GetMemberAccessorImpl(target);
     }

src/WireMock.Net.Minimal/WireMock.Net.Minimal.csproj

@@ -43,7 +43,7 @@
         <PackageReference Include="SimMetrics.Net" Version="1.0.5" />
         <PackageReference Include="TinyMapper.Signed" Version="4.0.0" />
         <PackageReference Include="Microsoft.IdentityModel.Protocols.OpenIdConnect" Version="6.34.0" />
-        <PackageReference Include="Scriban.Signed" Version="5.5.0" />
+        <PackageReference Include="Scriban.Signed" Version="7.0.6" />
     </ItemGroup>
 
     <ItemGroup>

src/WireMock.Net.Shared/Handlers/InMemoryScenarioStateStore.cs

@@ -0,0 +1,68 @@
+// Copyright © WireMock.Net
+
+using System.Collections.Concurrent;
+using System.Diagnostics.CodeAnalysis;
+
+namespace WireMock.Handlers;
+
+/// <summary>
+/// Provides an in-memory implementation of the <see cref="IScenarioStateStore" /> interface for managing scenario state objects by name.
+/// </summary>
+public class InMemoryScenarioStateStore : IScenarioStateStore
+{
+    private readonly ConcurrentDictionary<string, ScenarioState> _scenarios = new(StringComparer.OrdinalIgnoreCase);
+
+    /// <inheritdoc />
+    public bool TryGet(string name, [NotNullWhen(true)] out ScenarioState? state)
+    {
+        return _scenarios.TryGetValue(name, out state);
+    }
+
+    /// <inheritdoc />
+    public IReadOnlyList<ScenarioState> GetAll()
+    {
+        return _scenarios.Values.ToArray();
+    }
+
+    /// <inheritdoc />
+    public bool ContainsKey(string name)
+    {
+        return _scenarios.ContainsKey(name);
+    }
+
+    /// <inheritdoc />
+    public bool TryAdd(string name, ScenarioState scenarioState)
+    {
+        return _scenarios.TryAdd(name, scenarioState);
+    }
+
+    /// <inheritdoc />
+    public ScenarioState AddOrUpdate(string name, Func<string, ScenarioState> addFactory, Func<string, ScenarioState, ScenarioState> updateFactory)
+    {
+        return _scenarios.AddOrUpdate(name, addFactory, updateFactory);
+    }
+
+    /// <inheritdoc />
+    public ScenarioState? Update(string name, Action<ScenarioState> updateAction)
+    {
+        if (_scenarios.TryGetValue(name, out var state))
+        {
+            updateAction(state);
+            return state;
+        }
+
+        return null;
+    }
+
+    /// <inheritdoc />
+    public bool TryRemove(string name)
+    {
+        return _scenarios.TryRemove(name, out _);
+    }
+
+    /// <inheritdoc />
+    public void Clear()
+    {
+        _scenarios.Clear();
+    }
+}

src/WireMock.Net.Shared/Matchers/MatchResult.cs

@@ -1,6 +1,5 @@
 // Copyright © WireMock.Net
 
-using System.Linq;
 using Stef.Validation;
 using WireMock.Extensions;
 using WireMock.Matchers.Request;
@@ -119,7 +118,7 @@ public class MatchResult
         return new MatchDetail
         {
             Name = Name,
-            MatcherType = typeof(MatchResult),
+            MatcherType = typeof(MatchResult).Name,
             Score = Score,
             Exception = Exception,
             MatchDetails = MatchResults?.Select(mr => mr.ToMatchDetail()).ToArray()

src/WireMock.Net.Shared/Settings/WireMockServerSettings.cs

@@ -175,6 +175,17 @@ public class WireMockServerSettings
     [JsonIgnore]
     public IFileSystemHandler FileSystemHandler { get; set; } = null!;
 
+    /// <summary>
+    /// Gets or sets the store used to persist scenario state information.
+    /// </summary>
+    /// <remarks>
+    /// The scenario state store manages the storage and retrieval of state data associated with scenarios.
+    /// By default, an in-memory implementation is used, but this property can be set to a custom implementation to support alternative storage mechanisms such as databases or distributed caches.
+    /// </remarks>
+    [PublicAPI]
+    [JsonIgnore]
+    public IScenarioStateStore ScenarioStateStore { get; set; } = new InMemoryScenarioStateStore();
+
     /// <summary>
     /// Action which can be used to add additional Handlebars registrations. [Optional]
     /// </summary>
@@ -254,7 +265,7 @@ public class WireMockServerSettings
     /// Whether to accept any client certificate
     /// </summary>
     public bool AcceptAnyClientCertificate { get; set; }
-    
+
     /// <summary>
     /// Defines the global IWebhookSettings to use.
     /// </summary>

src/dotnet-WireMock.Net/Json/SourceGenerationContext.cs

@@ -1,6 +1,7 @@
 // Copyright © WireMock.Net
 
 using System.Text.Json.Serialization;
+using Newtonsoft.Json.Linq;
 using WireMock.Admin.Mappings;
 using WireMock.Admin.Requests;
 using WireMock.Types;
@@ -9,10 +10,13 @@ namespace WireMock.Net.Json;
 
 [JsonSourceGenerationOptions(WriteIndented = true)]
 [JsonSerializable(typeof(EncodingModel))]
+[JsonSerializable(typeof(JArray))]
+[JsonSerializable(typeof(JObject))]
 [JsonSerializable(typeof(LogEntryModel))]
 [JsonSerializable(typeof(LogRequestModel))]
 [JsonSerializable(typeof(LogResponseModel))]
 [JsonSerializable(typeof(LogRequestMatchModel))]
+[JsonSerializable(typeof(StatusModel))]
 [JsonSerializable(typeof(WireMockList<string>))]
 internal partial class SourceGenerationContext : JsonSerializerContext
 {

src/dotnet-WireMock.Net/WireMockLogger.cs

@@ -1,6 +1,5 @@
 // Copyright © WireMock.Net
 
-using System;
 using System.Text.Json;
 using Microsoft.Extensions.Logging;
 using WireMock.Admin.Requests;
@@ -11,11 +10,6 @@ namespace WireMock.Net;
 
 public class WireMockLogger : IWireMockLogger
 {
-    private readonly JsonSerializerOptions _options = new()
-    {
-        WriteIndented = true
-    };
-
     private readonly ILogger _logger;
 
     public WireMockLogger(ILogger logger)

test/WireMock.Net.Tests.UsingNuGet/WireMock.Net.Tests.UsingNuGet.csproj

@@ -11,12 +11,12 @@
 
     <ItemGroup>
         <PackageReference Include="AwesomeAssertions" Version="9.4.0" />
-        <PackageReference Include="coverlet.collector" Version="6.0.4">
+        <PackageReference Include="coverlet.collector" Version="8.0.1">
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
-        <PackageReference Include="WireMock.Net" Version="1.25.0" />
+        <PackageReference Include="WireMock.Net" Version="2.1.0" />
         <PackageReference Include="xunit.v3" Version="3.2.2" />
         <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
             <PrivateAssets>all</PrivateAssets>

test/WireMock.Net.Tests/Handlers/FileBasedScenarioStateStoreTests.cs

@@ -0,0 +1,273 @@
+// Copyright © WireMock.Net
+
+using System;
+using System.IO;
+using Newtonsoft.Json;
+using WireMock.Handlers;
+using Xunit;
+
+namespace WireMock.Net.Tests.Handlers;
+
+public class FileBasedScenarioStateStoreTests : IDisposable
+{
+    private readonly string _tempFolder;
+    private readonly string _scenariosFolder;
+
+    public FileBasedScenarioStateStoreTests()
+    {
+        _tempFolder = Path.Combine(Path.GetTempPath(), "WireMock_Tests_" + Guid.NewGuid().ToString("N"));
+        _scenariosFolder = Path.Combine(_tempFolder, "__admin", "scenarios");
+    }
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_tempFolder))
+        {
+            Directory.Delete(_tempFolder, true);
+        }
+    }
+
+    private FileBasedScenarioStateStore CreateSut() => new(_tempFolder);
+
+    // --- Mirror tests from InMemoryScenarioStateStoreTests ---
+
+    [Fact]
+    public void TryAdd_ShouldAddNewScenario()
+    {
+        var sut = CreateSut();
+        var state = new ScenarioState { Name = "scenario1" };
+
+        sut.TryAdd("scenario1", state).Should().BeTrue();
+
+        sut.ContainsKey("scenario1").Should().BeTrue();
+    }
+
+    [Fact]
+    public void TryAdd_ShouldReturnFalse_WhenScenarioAlreadyExists()
+    {
+        var sut = CreateSut();
+        var state = new ScenarioState { Name = "scenario1" };
+        sut.TryAdd("scenario1", state);
+
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" }).Should().BeFalse();
+    }
+
+    [Fact]
+    public void TryGet_ShouldReturnTrue_WhenExists()
+    {
+        var sut = CreateSut();
+        var state = new ScenarioState { Name = "scenario1", NextState = "state2" };
+        sut.TryAdd("scenario1", state);
+
+        sut.TryGet("scenario1", out var result).Should().BeTrue();
+
+        result.Should().NotBeNull();
+        result!.NextState.Should().Be("state2");
+    }
+
+    [Fact]
+    public void TryGet_ShouldReturnFalse_WhenNotExists()
+    {
+        var sut = CreateSut();
+        sut.TryGet("nonexistent", out var result).Should().BeFalse();
+        result.Should().BeNull();
+    }
+
+    [Fact]
+    public void GetAll_ShouldReturnAllScenarios()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+        sut.TryAdd("scenario2", new ScenarioState { Name = "scenario2" });
+
+        var result = sut.GetAll();
+
+        result.Should().HaveCount(2);
+    }
+
+    [Fact]
+    public void GetAll_ShouldReturnEmpty_WhenNoScenarios()
+    {
+        var sut = CreateSut();
+        sut.GetAll().Should().BeEmpty();
+    }
+
+    [Fact]
+    public void Update_ShouldModifyExistingScenario()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1", Counter = 0 });
+
+        var result = sut.Update("scenario1", s => { s.Counter = 5; s.NextState = "state2"; });
+
+        result.Should().NotBeNull();
+        result!.Counter.Should().Be(5);
+        result.NextState.Should().Be("state2");
+    }
+
+    [Fact]
+    public void Update_ShouldReturnNull_WhenNotExists()
+    {
+        var sut = CreateSut();
+        sut.Update("nonexistent", s => { s.Counter = 5; }).Should().BeNull();
+    }
+
+    [Fact]
+    public void AddOrUpdate_ShouldAddNewScenario()
+    {
+        var sut = CreateSut();
+        var result = sut.AddOrUpdate(
+            "scenario1",
+            _ => new ScenarioState { Name = "scenario1", NextState = "added" },
+            (_, current) => { current.NextState = "updated"; return current; }
+        );
+
+        result.NextState.Should().Be("added");
+    }
+
+    [Fact]
+    public void AddOrUpdate_ShouldUpdateExistingScenario()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1", NextState = "initial" });
+
+        var result = sut.AddOrUpdate(
+            "scenario1",
+            _ => new ScenarioState { Name = "scenario1", NextState = "added" },
+            (_, current) => { current.NextState = "updated"; return current; }
+        );
+
+        result.NextState.Should().Be("updated");
+    }
+
+    [Fact]
+    public void TryRemove_ShouldRemoveExistingScenario()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+
+        sut.TryRemove("scenario1").Should().BeTrue();
+        sut.ContainsKey("scenario1").Should().BeFalse();
+    }
+
+    [Fact]
+    public void TryRemove_ShouldReturnFalse_WhenNotExists()
+    {
+        var sut = CreateSut();
+        sut.TryRemove("nonexistent").Should().BeFalse();
+    }
+
+    [Fact]
+    public void Clear_ShouldRemoveAllScenarios()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+        sut.TryAdd("scenario2", new ScenarioState { Name = "scenario2" });
+
+        sut.Clear();
+
+        sut.GetAll().Should().BeEmpty();
+    }
+
+    [Fact]
+    public void ContainsKey_ShouldBeCaseInsensitive()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("Scenario1", new ScenarioState { Name = "Scenario1" });
+
+        sut.ContainsKey("scenario1").Should().BeTrue();
+        sut.ContainsKey("SCENARIO1").Should().BeTrue();
+    }
+
+    [Fact]
+    public void TryGet_ShouldBeCaseInsensitive()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("Scenario1", new ScenarioState { Name = "Scenario1", NextState = "state2" });
+
+        sut.TryGet("scenario1", out var result1).Should().BeTrue();
+        result1!.NextState.Should().Be("state2");
+
+        sut.TryGet("SCENARIO1", out var result2).Should().BeTrue();
+        result2!.NextState.Should().Be("state2");
+    }
+
+    // --- File-persistence-specific tests ---
+
+    [Fact]
+    public void TryAdd_ShouldCreateJsonFileOnDisk()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1", NextState = "state2" });
+
+        var filePath = Path.Combine(_scenariosFolder, "scenario1.json");
+        File.Exists(filePath).Should().BeTrue();
+
+        var json = File.ReadAllText(filePath);
+        var deserialized = JsonConvert.DeserializeObject<ScenarioState>(json);
+        deserialized!.Name.Should().Be("scenario1");
+        deserialized.NextState.Should().Be("state2");
+    }
+
+    [Fact]
+    public void TryRemove_ShouldDeleteJsonFileFromDisk()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+
+        var filePath = Path.Combine(_scenariosFolder, "scenario1.json");
+        File.Exists(filePath).Should().BeTrue();
+
+        sut.TryRemove("scenario1");
+
+        File.Exists(filePath).Should().BeFalse();
+    }
+
+    [Fact]
+    public void Clear_ShouldDeleteAllJsonFilesFromDisk()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+        sut.TryAdd("scenario2", new ScenarioState { Name = "scenario2" });
+
+        Directory.GetFiles(_scenariosFolder, "*.json").Should().HaveCount(2);
+
+        sut.Clear();
+
+        Directory.GetFiles(_scenariosFolder, "*.json").Should().BeEmpty();
+    }
+
+    [Fact]
+    public void Constructor_ShouldLoadExistingScenariosFromDisk()
+    {
+        // Pre-write JSON files before constructing the store
+        Directory.CreateDirectory(_scenariosFolder);
+        var state1 = new ScenarioState { Name = "scenario1", NextState = "loaded1" };
+        var state2 = new ScenarioState { Name = "scenario2", NextState = "loaded2", Counter = 3 };
+        File.WriteAllText(Path.Combine(_scenariosFolder, "scenario1.json"), JsonConvert.SerializeObject(state1));
+        File.WriteAllText(Path.Combine(_scenariosFolder, "scenario2.json"), JsonConvert.SerializeObject(state2));
+
+        var sut = CreateSut();
+
+        sut.GetAll().Should().HaveCount(2);
+        sut.TryGet("scenario1", out var loaded1).Should().BeTrue();
+        loaded1!.NextState.Should().Be("loaded1");
+        sut.TryGet("scenario2", out var loaded2).Should().BeTrue();
+        loaded2!.Counter.Should().Be(3);
+    }
+
+    [Fact]
+    public void Update_ShouldPersistChangesToDisk()
+    {
+        var sut = CreateSut();
+        sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1", Counter = 0 });
+
+        sut.Update("scenario1", s => { s.Counter = 10; s.NextState = "persisted"; });
+
+        var filePath = Path.Combine(_scenariosFolder, "scenario1.json");
+        var json = File.ReadAllText(filePath);
+        var deserialized = JsonConvert.DeserializeObject<ScenarioState>(json);
+        deserialized!.Counter.Should().Be(10);
+        deserialized.NextState.Should().Be("persisted");
+    }
+}

test/WireMock.Net.Tests/Handlers/InMemoryScenarioStateStoreTests.cs

@@ -0,0 +1,157 @@
+// Copyright © WireMock.Net
+
+using WireMock.Handlers;
+using Xunit;
+
+namespace WireMock.Net.Tests.Handlers;
+
+public class InMemoryScenarioStateStoreTests
+{
+    private readonly InMemoryScenarioStateStore _sut = new();
+
+    [Fact]
+    public void TryAdd_ShouldAddNewScenario()
+    {
+        var state = new ScenarioState { Name = "scenario1" };
+
+        _sut.TryAdd("scenario1", state).Should().BeTrue();
+
+        _sut.ContainsKey("scenario1").Should().BeTrue();
+    }
+
+    [Fact]
+    public void TryAdd_ShouldReturnFalse_WhenScenarioAlreadyExists()
+    {
+        var state = new ScenarioState { Name = "scenario1" };
+        _sut.TryAdd("scenario1", state);
+
+        _sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" }).Should().BeFalse();
+    }
+
+    [Fact]
+    public void TryGet_ShouldReturnTrue_WhenExists()
+    {
+        var state = new ScenarioState { Name = "scenario1", NextState = "state2" };
+        _sut.TryAdd("scenario1", state);
+
+        _sut.TryGet("scenario1", out var result).Should().BeTrue();
+
+        result.Should().NotBeNull();
+        result!.NextState.Should().Be("state2");
+    }
+
+    [Fact]
+    public void TryGet_ShouldReturnFalse_WhenNotExists()
+    {
+        _sut.TryGet("nonexistent", out var result).Should().BeFalse();
+        result.Should().BeNull();
+    }
+
+    [Fact]
+    public void GetAll_ShouldReturnAllScenarios()
+    {
+        _sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+        _sut.TryAdd("scenario2", new ScenarioState { Name = "scenario2" });
+
+        var result = _sut.GetAll();
+
+        result.Should().HaveCount(2);
+    }
+
+    [Fact]
+    public void GetAll_ShouldReturnEmpty_WhenNoScenarios()
+    {
+        _sut.GetAll().Should().BeEmpty();
+    }
+
+    [Fact]
+    public void Update_ShouldModifyExistingScenario()
+    {
+        _sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1", Counter = 0 });
+
+        var result = _sut.Update("scenario1", s => { s.Counter = 5; s.NextState = "state2"; });
+
+        result.Should().NotBeNull();
+        result!.Counter.Should().Be(5);
+        result.NextState.Should().Be("state2");
+    }
+
+    [Fact]
+    public void Update_ShouldReturnNull_WhenNotExists()
+    {
+        _sut.Update("nonexistent", s => { s.Counter = 5; }).Should().BeNull();
+    }
+
+    [Fact]
+    public void AddOrUpdate_ShouldAddNewScenario()
+    {
+        var result = _sut.AddOrUpdate(
+            "scenario1",
+            _ => new ScenarioState { Name = "scenario1", NextState = "added" },
+            (_, current) => { current.NextState = "updated"; return current; }
+        );
+
+        result.NextState.Should().Be("added");
+    }
+
+    [Fact]
+    public void AddOrUpdate_ShouldUpdateExistingScenario()
+    {
+        _sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1", NextState = "initial" });
+
+        var result = _sut.AddOrUpdate(
+            "scenario1",
+            _ => new ScenarioState { Name = "scenario1", NextState = "added" },
+            (_, current) => { current.NextState = "updated"; return current; }
+        );
+
+        result.NextState.Should().Be("updated");
+    }
+
+    [Fact]
+    public void TryRemove_ShouldRemoveExistingScenario()
+    {
+        _sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+
+        _sut.TryRemove("scenario1").Should().BeTrue();
+        _sut.ContainsKey("scenario1").Should().BeFalse();
+    }
+
+    [Fact]
+    public void TryRemove_ShouldReturnFalse_WhenNotExists()
+    {
+        _sut.TryRemove("nonexistent").Should().BeFalse();
+    }
+
+    [Fact]
+    public void Clear_ShouldRemoveAllScenarios()
+    {
+        _sut.TryAdd("scenario1", new ScenarioState { Name = "scenario1" });
+        _sut.TryAdd("scenario2", new ScenarioState { Name = "scenario2" });
+
+        _sut.Clear();
+
+        _sut.GetAll().Should().BeEmpty();
+    }
+
+    [Fact]
+    public void ContainsKey_ShouldBeCaseInsensitive()
+    {
+        _sut.TryAdd("Scenario1", new ScenarioState { Name = "Scenario1" });
+
+        _sut.ContainsKey("scenario1").Should().BeTrue();
+        _sut.ContainsKey("SCENARIO1").Should().BeTrue();
+    }
+
+    [Fact]
+    public void TryGet_ShouldBeCaseInsensitive()
+    {
+        _sut.TryAdd("Scenario1", new ScenarioState { Name = "Scenario1", NextState = "state2" });
+
+        _sut.TryGet("scenario1", out var result1).Should().BeTrue();
+        result1!.NextState.Should().Be("state2");
+
+        _sut.TryGet("SCENARIO1", out var result2).Should().BeTrue();
+        result2!.NextState.Should().Be("state2");
+    }
+}

test/WireMock.Net.Tests/Http/HttpRequestMessageHelperTests.cs

@@ -27,7 +27,7 @@ public class HttpRequestMessageHelperTests
         var message = HttpRequestMessageHelper.Create(request, "http://url");
 
         // Assert
-        message.Headers.GetValues("x").Should().Equal(new[] { "value-1" });
+        message.Headers.GetValues("x").Should().Equal(["value-1"]);
     }
 
     [Fact]
@@ -101,7 +101,7 @@ public class HttpRequestMessageHelperTests
 
         // Assert
         (await message.Content!.ReadAsStringAsync(_ct)).Should().Be("{\"x\":42}");
-        message.Content.Headers.GetValues("Content-Type").Should().Equal(new[] { "application/json" });
+        message.Content.Headers.GetValues("Content-Type").Should().Equal(["application/json"]);
     }
 
     [Fact]
@@ -121,7 +121,7 @@ public class HttpRequestMessageHelperTests
 
         // Assert
         (await message.Content!.ReadAsStringAsync(_ct)).Should().Be("{\"x\":42}");
-        message.Content.Headers.GetValues("Content-Type").Should().Equal(new[] { "application/json; charset=utf-8" });
+        message.Content.Headers.GetValues("Content-Type").Should().Equal(["application/json; charset=utf-8"]);
     }
 
     [Fact]
@@ -142,7 +142,7 @@ public class HttpRequestMessageHelperTests
 
         // Assert
         (await message.Content!.ReadAsStringAsync(_ct)).Should().Be("{\"x\":42}");
-        message.Content.Headers.GetValues("Content-Type").Should().Equal(new[] { "multipart/form-data" });
+        message.Content.Headers.GetValues("Content-Type").Should().Equal(["multipart/form-data"]);
     }
 
 
@@ -162,7 +162,7 @@ public class HttpRequestMessageHelperTests
         var message = HttpRequestMessageHelper.Create(request, "http://url");
 
         // Assert
-        message.Content!.Headers.GetValues("Content-Type").Should().Equal(new[] { "application/xml" });
+        message.Content!.Headers.GetValues("Content-Type").Should().Equal(["application/xml"]);
     }
 
     [Fact]
@@ -181,7 +181,7 @@ public class HttpRequestMessageHelperTests
         var message = HttpRequestMessageHelper.Create(request, "http://url");
 
         // Assert
-        message.Content!.Headers.GetValues("Content-Type").Should().Equal(new[] { "application/xml; charset=UTF-8" });
+        message.Content!.Headers.GetValues("Content-Type").Should().Equal(["application/xml; charset=UTF-8"]);
     }
 
     [Fact]
@@ -200,7 +200,7 @@ public class HttpRequestMessageHelperTests
         var message = HttpRequestMessageHelper.Create(request, "http://url");
 
         // Assert
-        message.Content!.Headers.GetValues("Content-Type").Should().Equal(new[] { "application/xml; charset=Ascii" });
+        message.Content!.Headers.GetValues("Content-Type").Should().Equal(["application/xml; charset=Ascii"]);
     }
 
     [Fact]
@@ -242,7 +242,7 @@ public class HttpRequestMessageHelperTests
 
         // Assert
         (await message.Content!.ReadAsStringAsync(_ct)).Should().Be(body);
-        message.Content.Headers.GetValues("Content-Type").Should().Equal(new[] { "multipart/form-data" });
+        message.Content.Headers.GetValues("Content-Type").Should().Equal(["multipart/form-data"]);
     }
 
     [Theory]
@@ -269,7 +269,4 @@ public class HttpRequestMessageHelperTests
         // Assert
         message.Content?.Headers.ContentLength.Should().Be(resultShouldBe ? value : null);
     }
-}
+}
-
-
-

test/WireMock.Net.Tests/Owin/MappingMatcherTests.cs

@@ -2,6 +2,7 @@
 
 using System.Collections.Concurrent;
 using Moq;
+using WireMock.Handlers;
 using WireMock.Logging;
 using WireMock.Matchers.Request;
 using WireMock.Models;
@@ -23,7 +24,7 @@ public class MappingMatcherTests
         _optionsMock.SetupAllProperties();
         _optionsMock.Setup(o => o.Mappings).Returns(new ConcurrentDictionary<Guid, IMapping>());
         _optionsMock.Setup(o => o.LogEntries).Returns([]);
-        _optionsMock.Setup(o => o.Scenarios).Returns(new ConcurrentDictionary<string, ScenarioState>());
+        _optionsMock.Setup(o => o.ScenarioStateStore).Returns(new InMemoryScenarioStateStore());
 
         var loggerMock = new Mock<IWireMockLogger>();
         loggerMock.SetupAllProperties();

test/WireMock.Net.Tests/Owin/WireMockMiddlewareTests.cs

@@ -55,7 +55,7 @@ public class WireMockMiddlewareTests
         _optionsMock.SetupAllProperties();
         _optionsMock.Setup(o => o.Mappings).Returns(_mappings);
         _optionsMock.Setup(o => o.LogEntries).Returns(new ConcurrentObservableCollection<LogEntry>());
-        _optionsMock.Setup(o => o.Scenarios).Returns(new ConcurrentDictionary<string, ScenarioState>());
+        _optionsMock.Setup(o => o.ScenarioStateStore).Returns(new InMemoryScenarioStateStore());
         _optionsMock.Setup(o => o.Logger.Warn(It.IsAny<string>(), It.IsAny<object[]>()));
         _optionsMock.Setup(o => o.Logger.Error(It.IsAny<string>(), It.IsAny<object[]>()));
         _optionsMock.Setup(o => o.Logger.DebugRequestResponse(It.IsAny<LogEntryModel>(), It.IsAny<bool>()));

test/WireMock.Net.Tests/StatefulBehaviorTests.cs

@@ -325,26 +325,26 @@ public class StatefulBehaviorTests
         var getResponse1 = await client.GetStringAsync("/todo/items", cancelationToken);
         getResponse1.Should().Be("Buy milk");
 
-        server.Scenarios["To do list"].Name.Should().Be("To do list");
+        server.Scenarios.First(s => s.Name == "To do list").Name.Should().Be("To do list");
-        server.Scenarios["To do list"].NextState.Should().Be("TodoList State Started");
+        server.Scenarios.First(s => s.Name == "To do list").NextState.Should().Be("TodoList State Started");
-        server.Scenarios["To do list"].Started.Should().BeTrue();
+        server.Scenarios.First(s => s.Name == "To do list").Started.Should().BeTrue();
-        server.Scenarios["To do list"].Finished.Should().BeFalse();
+        server.Scenarios.First(s => s.Name == "To do list").Finished.Should().BeFalse();
 
         var postResponse = await client.PostAsync("/todo/items", new StringContent("Cancel newspaper subscription"), cancelationToken);
         postResponse.StatusCode.Should().Be(HttpStatusCode.Created);
 
-        server.Scenarios["To do list"].Name.Should().Be("To do list");
+        server.Scenarios.First(s => s.Name == "To do list").Name.Should().Be("To do list");
-        server.Scenarios["To do list"].NextState.Should().Be("Cancel newspaper item added");
+        server.Scenarios.First(s => s.Name == "To do list").NextState.Should().Be("Cancel newspaper item added");
-        server.Scenarios["To do list"].Started.Should().BeTrue();
+        server.Scenarios.First(s => s.Name == "To do list").Started.Should().BeTrue();
-        server.Scenarios["To do list"].Finished.Should().BeFalse();
+        server.Scenarios.First(s => s.Name == "To do list").Finished.Should().BeFalse();
 
         string getResponse2 = await client.GetStringAsync("/todo/items", cancelationToken);
         getResponse2.Should().Be("Buy milk;Cancel newspaper subscription");
 
-        server.Scenarios["To do list"].Name.Should().Be("To do list");
+        server.Scenarios.First(s => s.Name == "To do list").Name.Should().Be("To do list");
-        server.Scenarios["To do list"].NextState.Should().BeNull();
+        server.Scenarios.First(s => s.Name == "To do list").NextState.Should().BeNull();
-        server.Scenarios["To do list"].Started.Should().BeTrue();
+        server.Scenarios.First(s => s.Name == "To do list").Started.Should().BeTrue();
-        server.Scenarios["To do list"].Finished.Should().BeTrue();
+        server.Scenarios.First(s => s.Name == "To do list").Finished.Should().BeTrue();
 
         server.Stop();
     }
@@ -372,14 +372,14 @@ public class StatefulBehaviorTests
 
         // Act and Assert
         server.SetScenarioState(scenario, "Buy milk");
-        server.Scenarios[scenario].Should().BeEquivalentTo(new { Name = scenario, NextState = "Buy milk" });
+        server.Scenarios.First(s => s.Name == scenario).Should().BeEquivalentTo(new { Name = scenario, NextState = "Buy milk" });
-        
+
         var getResponse1 = await client.GetStringAsync("/todo/items", cancelationToken);
         getResponse1.Should().Be("Buy milk");
 
         server.SetScenarioState(scenario, "Cancel newspaper");
-        server.Scenarios[scenario].Name.Should().Be(scenario);
+        server.Scenarios.First(s => s.Name == scenario).Name.Should().Be(scenario);
-        server.Scenarios[scenario].Should().BeEquivalentTo(new { Name = scenario, NextState = "Cancel newspaper" });
+        server.Scenarios.First(s => s.Name == scenario).Should().BeEquivalentTo(new { Name = scenario, NextState = "Cancel newspaper" });
 
         var getResponse2 = await client.GetStringAsync("/todo/items", cancelationToken);
         getResponse2.Should().Be("Buy milk;Cancel newspaper subscription");
@@ -413,6 +413,120 @@ public class StatefulBehaviorTests
         action.Should().ThrowAsync<HttpRequestException>();
     }
 
+    [Fact]
+    public async Task Scenarios_FirstRequestWithDelay_StateTransitions_BeforeDelayCompletes()
+    {
+        // Arrange
+        var cancellationToken = TestContext.Current.CancellationToken;
+        var path = $"/foo_{Guid.NewGuid()}";
+        using var server = WireMockServer.Start();
+
+        // Mapping 1: start state, has a 500 ms delay
+        server
+            .Given(Request.Create().WithPath(path).UsingGet())
+            .InScenario("1260")
+            .WillSetStateTo("State1")
+            .RespondWith(Response.Create()
+                .WithBody("delayed response")
+                .WithDelay(TimeSpan.FromMilliseconds(500)));
+
+        // Mapping 2: only matches after state has transitioned to "State1"
+        server
+            .Given(Request.Create().WithPath(path).UsingGet())
+            .InScenario("1260")
+            .WhenStateIs("State1")
+            .RespondWith(Response.Create().WithBody("immediate response"));
+
+        var client = new HttpClient();
+
+        // Act: fire request 1 but don't await it yet — it will sit in a 500 ms delay
+        var request1Task = client.GetStringAsync(server.Url + path, cancellationToken);
+
+        // Give the server a moment to match & transition state before the delay completes
+        await Task.Delay(100, cancellationToken);
+
+        // Request 2 is sent while request 1 is still being delayed.
+        // After the fix the state has already transitioned, so request 2 matches Mapping 2.
+        var response2 = await client.GetStringAsync(server.Url + path, cancellationToken);
+
+        var response1 = await request1Task;
+
+        // Assert
+        response1.Should().Be("delayed response");
+        response2.Should().Be("immediate response");
+    }
+
+    [Fact]
+    public async Task Scenarios_WithGlobalRequestProcessingDelay_StateTransitions_BeforeDelayCompletes()
+    {
+        // Arrange: use the global RequestProcessingDelay instead of a per-mapping delay
+        var cancellationToken = TestContext.Current.CancellationToken;
+        var path = $"/foo_{Guid.NewGuid()}";
+        using var server = WireMockServer.Start();
+        server.AddGlobalProcessingDelay(TimeSpan.FromMilliseconds(500));
+
+        server
+            .Given(Request.Create().WithPath(path).UsingGet())
+            .InScenario("s")
+            .WillSetStateTo("State1")
+            .RespondWith(Response.Create().WithBody("delayed response"));
+
+        server
+            .Given(Request.Create().WithPath(path).UsingGet())
+            .InScenario("s")
+            .WhenStateIs("State1")
+            .RespondWith(Response.Create().WithBody("immediate response"));
+
+        var client = new HttpClient();
+
+        // Act
+        var request1Task = client.GetStringAsync(server.Url + path, cancellationToken);
+        await Task.Delay(100, cancellationToken);
+        var response2 = await client.GetStringAsync(server.Url + path, cancellationToken);
+        var response1 = await request1Task;
+
+        // Assert
+        response1.Should().Be("delayed response");
+        response2.Should().Be("immediate response");
+    }
+
+    [Fact]
+    public async Task Scenarios_WithDelay_And_TimesInSameState_Should_Transition_After_Required_Hits()
+    {
+        // Arrange
+        var cancellationToken = TestContext.Current.CancellationToken;
+        var path = $"/foo_{Guid.NewGuid()}";
+        using var server = WireMockServer.Start();
+
+        // Mapping 1: requires 2 hits before transitioning; has a short delay
+        server
+            .Given(Request.Create().WithPath(path).UsingGet())
+            .InScenario("s")
+            .WillSetStateTo("State1", 2)
+            .RespondWith(Response.Create()
+                .WithBody("first")
+                .WithDelay(TimeSpan.FromMilliseconds(50)));
+
+        // Mapping 2: matches after state is "State1"
+        server
+            .Given(Request.Create().WithPath(path).UsingGet())
+            .InScenario("s")
+            .WhenStateIs("State1")
+            .RespondWith(Response.Create().WithBody("second"));
+
+        var client = new HttpClient();
+
+        // Act
+        var response1 = await client.GetStringAsync(server.Url + path, cancellationToken);
+        var response2 = await client.GetStringAsync(server.Url + path, cancellationToken);
+        var response3 = await client.GetStringAsync(server.Url + path, cancellationToken);
+
+        // Assert: state only transitions after 2 hits, so request 3 is the first to match Mapping 2
+        response1.Should().Be("first");
+        response2.Should().Be("first");
+        response3.Should().Be("second");
+    }
+
     [Fact]
     public async Task Scenarios_Should_process_request_if_equals_state_and_multiple_state_defined()
     {

test/WireMock.Net.Tests/WebSockets/WebSocketIntegrationTests.cs

@@ -706,7 +706,7 @@ public class WebSocketIntegrationTests(ITestOutputHelper output, ITestContextAcc
     public async Task WithWebSocketProxy_Should_Proxy_Multiple_TextMessages()
     {
         // Arrange - Start target echo server
-        using var exampleEchoServer = WireMockServer.Start(new WireMockServerSettings
+        var exampleEchoServer = WireMockServer.Start(new WireMockServerSettings
         {
             Logger = new TestOutputHelperWireMockLogger(output),
             Urls = ["ws://localhost:0"]
@@ -722,7 +722,7 @@ public class WebSocketIntegrationTests(ITestOutputHelper output, ITestContextAcc
             );
 
         // Arrange - Start proxy server
-        using var sut = WireMockServer.Start(new WireMockServerSettings
+        var sut = WireMockServer.Start(new WireMockServerSettings
         {
             Logger = new TestOutputHelperWireMockLogger(output),
             Urls = ["ws://localhost:0"]
@@ -755,13 +755,21 @@ public class WebSocketIntegrationTests(ITestOutputHelper output, ITestContextAcc
         }
 
         await client.CloseAsync(WebSocketCloseStatus.NormalClosure, "Test complete", _ct);
+
+        await Task.Delay(250, _ct);
+
+        sut.Stop();
+        sut.Dispose();
+
+        exampleEchoServer.Stop();
+        exampleEchoServer.Dispose();
     }
 
     [Fact]
     public async Task WithWebSocketProxy_Should_Proxy_Binary_Messages()
     {
         // Arrange - Start target echo server
-        using var exampleEchoServer = WireMockServer.Start(new WireMockServerSettings
+        var exampleEchoServer = WireMockServer.Start(new WireMockServerSettings
         {
             Logger = new TestOutputHelperWireMockLogger(output),
             Urls = ["ws://localhost:0"]
@@ -777,7 +785,7 @@ public class WebSocketIntegrationTests(ITestOutputHelper output, ITestContextAcc
             );
 
         // Arrange - Start proxy server
-        using var sut = WireMockServer.Start(new WireMockServerSettings
+        var sut = WireMockServer.Start(new WireMockServerSettings
         {
             Logger = new TestOutputHelperWireMockLogger(output),
             Urls = ["ws://localhost:0"]
@@ -803,14 +811,22 @@ public class WebSocketIntegrationTests(ITestOutputHelper output, ITestContextAcc
         // Act
         await client.SendAsync(new ArraySegment<byte>(testData), WebSocketMessageType.Binary, true, _ct);
 
-        var receivedData = await client.ReceiveAsBytesAsync(cancellationToken: _ct);
-
         await Task.Delay(500, _ct);
 
+        var receivedData = await client.ReceiveAsBytesAsync(cancellationToken: _ct);
+
         // Assert
         receivedData.Should().BeEquivalentTo(testData, "binary data should be proxied and echoed back");
 
         await client.CloseAsync(WebSocketCloseStatus.NormalClosure, "Test complete", _ct);
+
+        await Task.Delay(250, _ct);
+
+        sut.Stop();
+        sut.Dispose();
+
+        exampleEchoServer.Stop();
+        exampleEchoServer.Dispose();
     }
 
     [Fact]

test/WireMock.Net.Tests/WireMock.Net.Tests.csproj

@@ -64,6 +64,7 @@
         </PackageReference>
         <PackageReference Include="Meziantou.Extensions.Logging.Xunit.v3" Version="1.1.24" />
         <PackageReference Include="Verify.XunitV3" Version="31.13.2" />
+        <PackageReference Include="xRetry.v3" Version="1.0.0-rc3" />
         <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

test/WireMock.Net.Tests/WireMockServerTests.cs

@@ -431,8 +431,13 @@ public partial class WireMockServerTests(ITestOutputHelper testOutputHelper)
         using var server = WireMockServer.Start();
 
         server
-            .Given(Request.Create().WithPath(path).UsingHead())
+            .WhenRequest(r => r
-            .RespondWith(Response.Create().WithHeader(HttpKnownHeaderNames.ContentLength, length));
+                .WithPath(path)
+                .UsingHead()
+            )
+            .ThenRespondWith(r => r
+                .WithHeader(HttpKnownHeaderNames.ContentLength, length)
+            );
 
         // Act
         var httpRequestMessage = new HttpRequestMessage(HttpMethod.Head, path);
@@ -442,6 +447,45 @@ public partial class WireMockServerTests(ITestOutputHelper testOutputHelper)
         response.Content.Headers.GetValues(HttpKnownHeaderNames.ContentLength).Should().Contain(length);
     }
 
+#if NET8_0_OR_GREATER
+    [Theory]
+    [InlineData("DELETE")]
+    [InlineData("GET")]
+    [InlineData("OPTIONS")]
+    [InlineData("PATCH")]
+    [InlineData("POST")]
+    [InlineData("PUT")]
+    [InlineData("TRACE")]
+    public async Task WireMockServer_Should_LogAndThrowExceptionWhenInvalidContentLength(string method)
+    {
+        // Assign
+        const string length = "42";
+        var path = $"/InvalidContentLength_{Guid.NewGuid()}";
+        using var server = WireMockServer.Start(new WireMockServerSettings
+        {
+            Logger = new TestOutputHelperWireMockLogger(testOutputHelper)
+        });
+
+        server
+            .WhenRequest(r => r
+                .WithPath(path)
+                .UsingAnyMethod()
+            )
+            .ThenRespondWith(r => r
+                .WithStatusCode(HttpStatusCode.OK)
+                .WithHeader(HttpKnownHeaderNames.ContentLength, length)
+            );
+
+        // Act
+        var httpRequestMessage = new HttpRequestMessage(HttpMethod.Parse(method), path);
+        var response = await server.CreateClient().SendAsync(httpRequestMessage, _ct);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.InternalServerError);
+        testOutputHelper.Output.Should().Contain($"Response Content-Length mismatch: too few bytes written (0 of {length}).");
+    }
+#endif
+
     [Theory]
     [InlineData("TRACE")]
     [InlineData("GET")]