Add an option to log unsupported route

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Logging/HttpLoggingRedactionInterceptor.cs

@@ -33,6 +33,7 @@ internal sealed class HttpLoggingRedactionInterceptor : IHttpLoggingInterceptor
     private readonly HeaderReader _responseHeadersReader;
     private readonly string[] _excludePathStartsWith;
     private readonly FrozenDictionary<string, DataClassification> _parametersToRedactMap;
+    private readonly bool _reportUnmatchedRoutes;
 
     public HttpLoggingRedactionInterceptor(
         IOptions<LoggingRedactionOptions> options,
@@ -59,6 +60,7 @@ public HttpLoggingRedactionInterceptor(
         _responseHeadersReader = new(optionsValue.ResponseHeadersDataClasses, redactorProvider, HttpLoggingTagNames.ResponseHeaderPrefix);
 
         _excludePathStartsWith = optionsValue.ExcludePathStartsWith.ToArray();
+        _reportUnmatchedRoutes = optionsValue.ReportUnmatchedRoutes;
     }
 
     public ValueTask OnRequestAsync(HttpLoggingInterceptorContext logContext)
@@ -115,6 +117,10 @@ public ValueTask OnRequestAsync(HttpLoggingInterceptorContext logContext)
                         }
                     }
                 }
+                else if (_reportUnmatchedRoutes)
+                {
+                    path = context.Request.Path.ToString();
+                }
             }
             else if (request.Path.HasValue)
             {

src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Logging/LoggingRedactionOptions.cs

@@ -100,6 +100,11 @@
 #pragma warning disable CA2227 // Collection properties should be read only
     public ISet<string> ExcludePathStartsWith { get; set; } = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
 #pragma warning restore CA2227 // Collection properties should be read only
+
+    /// <summary>
+    /// Gets or sets a value indicating whether to report unmatched routes.
+    /// </summary>
+    public bool ReportUnmatchedRoutes { get; set; } = false;
 }
 
 #endif

test/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware.Tests/Logging/AcceptanceTests.cs

@@ -224,13 +224,13 @@ await RunAsync(
                 x.MediaTypeOptions.Clear();
                 x.MediaTypeOptions.AddText("text/*");
                 x.LoggingFields |= HttpLoggingFields.RequestBody;
-            }).AddHttpLoggingRedaction(),
+            }).AddHttpLoggingRedaction(options => options.ReportUnmatchedRoutes = true),
             async (logCollector, client) =>
             {
                 const string Content = "Client: hello!";
 
                 using var content = new StringContent(Content, null, requestContentType);
-                using var response = await client.PostAsync("/", content).ConfigureAwait(false);
+                using var response = await client.PostAsync("/myroute/123", content).ConfigureAwait(false);
                 Assert.True(response.IsSuccessStatusCode);
 
                 await WaitForLogRecordsAsync(logCollector, _defaultLogTimeout);
@@ -247,7 +247,7 @@ await RunAsync(
                 Assert.DoesNotContain(state, x => x.Key.StartsWith(HttpLoggingTagNames.RequestHeaderPrefix));
                 Assert.DoesNotContain(state, x => x.Key.StartsWith(HttpLoggingTagNames.ResponseHeaderPrefix));
                 Assert.Single(state, x => x.Key == HttpLoggingTagNames.Host && !string.IsNullOrEmpty(x.Value));
-                Assert.Single(state, x => x.Key == HttpLoggingTagNames.Path && x.Value == TelemetryConstants.Unknown);
+                Assert.Single(state, x => x.Key == HttpLoggingTagNames.Path && x.Value == "/myroute/123");
                 Assert.Single(state, x => x.Key == HttpLoggingTagNames.StatusCode && x.Value == responseStatus);
                 Assert.Single(state, x => x.Key == HttpLoggingTagNames.Method && x.Value == HttpMethod.Post.ToString());
                 Assert.Single(state, x => x.Key == HttpLoggingTagNames.Duration &&