add missing file

Author: AlessiaYChen

tools/auto-clipper-harness/ResponseCaptureHandler.cs

@@ -0,0 +1,31 @@
+using System.IO;
+using System.Net.Http;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+internal sealed class ResponseCaptureHandler : DelegatingHandler
+{
+    private readonly string _path;
+
+    public ResponseCaptureHandler(string path) : base(new HttpClientHandler())
+    {
+        _path = path;
+    }
+
+    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+    {
+        var response = await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
+        try
+        {
+            var body = await response.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);
+            await File.WriteAllTextAsync(_path, body, cancellationToken).ConfigureAwait(false);
+            response.Content = new StringContent(body, Encoding.UTF8, response.Content.Headers?.ContentType?.MediaType ?? "application/json");
+        }
+        catch
+        {
+        }
+
+        return response;
+    }
+}