Add WireMock.Net.AspNetCore.Middleware (#1175)

* Add WireMock.Net.AspNetCore.Middleware

* .

* WireMock.Net.Middleware.Tests

* .

* X-WireMock-Response-Delay

src/WireMock.Net.AspNetCore.Middleware/WireMockBackgroundService.cs

@@ -0,0 +1,39 @@
+// Copyright © WireMock.Net
+
+using Microsoft.Extensions.Hosting;
+using Stef.Validation;
+using WireMock.Server;
+
+namespace WireMock.Net.AspNetCore.Middleware;
+
+/// <summary>
+/// A <see cref="BackgroundService"/> used to start/stop the <see cref="WireMockServer"/>
+/// </summary>
+internal class WireMockBackgroundService : BackgroundService
+{
+    private readonly WireMockServerInstance _serverInstance;
+
+    /// <summary>
+    /// Creates a new <see cref="BackgroundService"/> using an instance
+    /// of <see cref="WireMockServerInstance"/>
+    /// </summary>
+    /// <param name="serverInstance"></param>
+    public WireMockBackgroundService(WireMockServerInstance serverInstance)
+    {
+        _serverInstance = Guard.NotNull(serverInstance);
+    }
+
+    /// <inheritdoc />
+    protected override Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        _serverInstance.Start();
+        return Task.CompletedTask;
+    }
+
+    /// <inheritdoc />
+    public override Task StopAsync(CancellationToken cancellationToken)
+    {
+        _serverInstance.Stop();
+        return base.StopAsync(cancellationToken);
+    }
+}