[Blazor][Fixes #15155] Clarifies the message to turn on detailed erro… (#15156)

Fixes https://github.com/aspnet/AspNetCore/issues/15155

src/Components/Server/src/Circuits/CircuitHost.cs

@@ -225,7 +225,7 @@ namespace Microsoft.AspNetCore.Components.Server.Circuits
             Log.ConnectionUp(_logger, CircuitId, Client.ConnectionId);
 
             Renderer.Dispatcher.AssertAccess();
-            
+
             List<Exception> exceptions = null;
 
             for (var i = 0; i < _circuitHandlers.Length; i++)
@@ -254,7 +254,7 @@ namespace Microsoft.AspNetCore.Components.Server.Circuits
             Log.ConnectionDown(_logger, CircuitId, Client.ConnectionId);
 
             Renderer.Dispatcher.AssertAccess();
-            
+
             List<Exception> exceptions = null;
 
             for (var i = 0; i < _circuitHandlers.Length; i++)
@@ -545,7 +545,7 @@ namespace Microsoft.AspNetCore.Components.Server.Circuits
             else
             {
                 return $"There was an unhandled exception on the current circuit, so this circuit will be terminated. For more details turn on " +
-                    $"detailed exceptions in '{typeof(CircuitOptions).Name}.{nameof(CircuitOptions.DetailedErrors)}'. {additionalInformation}";
+                    $"detailed exceptions by setting 'DetailedErrors: true' in 'appSettings.Development.json' or set '{typeof(CircuitOptions).Name}.{nameof(CircuitOptions.DetailedErrors)}'. {additionalInformation}";
             }
         }
 

src/Components/test/E2ETest/ServerExecutionTests/ComponentHubInvalidEventTest.cs

@@ -38,7 +38,7 @@ namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
         {
             // Arrange
             var expectedError = $"There was an unhandled exception on the current circuit, so this circuit will be terminated. For more details turn on " +
-                $"detailed exceptions in 'CircuitOptions.DetailedErrors'. Bad input data.";
+                $"detailed exceptions by setting 'DetailedErrors: true' in 'appSettings.Development.json' or set 'CircuitOptions.DetailedErrors'. Bad input data.";
 
             var eventDescriptor = Serialize(new WebEventDescriptor()
             {
@@ -65,7 +65,7 @@ namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
         {
             // Arrange
             var expectedError = $"There was an unhandled exception on the current circuit, so this circuit will be terminated. For more details turn on " +
-                $"detailed exceptions in 'CircuitOptions.DetailedErrors'. Failed to dispatch event.";
+                $"detailed exceptions by setting 'DetailedErrors: true' in 'appSettings.Development.json' or set 'CircuitOptions.DetailedErrors'. Failed to dispatch event.";
 
             var eventDescriptor = Serialize(new WebEventDescriptor()
             {
@@ -105,7 +105,7 @@ namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
         {
             // Arrange
             var expectedError = $"There was an unhandled exception on the current circuit, so this circuit will be terminated. For more details turn on " +
-                $"detailed exceptions in 'CircuitOptions.DetailedErrors'. Failed to complete render batch '1846'.";
+                $"detailed exceptions by setting 'DetailedErrors: true' in 'appSettings.Development.json' or set 'CircuitOptions.DetailedErrors'. Failed to complete render batch '1846'.";
 
 
             Client.ConfirmRenderBatch = false;

src/Components/test/E2ETest/ServerExecutionTests/ComponentHubReliabilityTest.cs

@@ -216,7 +216,7 @@ namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
         {
             // Arrange
             var expectedError = "There was an unhandled exception on the current circuit, so this circuit will be terminated. " +
-                "For more details turn on detailed exceptions in 'CircuitOptions.DetailedErrors'. " +
+                "For more details turn on detailed exceptions by setting 'DetailedErrors: true' in 'appSettings.Development.json' or set 'CircuitOptions.DetailedErrors'. " +
                 "Location change to 'http://example.com' failed.";
 
             var rootUri = ServerFixture.RootUri;
@@ -245,7 +245,7 @@ namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
         {
             // Arrange
             var expectedError = "There was an unhandled exception on the current circuit, so this circuit will be terminated. " +
-                "For more details turn on detailed exceptions in 'CircuitOptions.DetailedErrors'. " +
+                "For more details turn on detailed exceptions by setting 'DetailedErrors: true' in 'appSettings.Development.json' or set 'CircuitOptions.DetailedErrors'. " +
                 "Location change failed.";
 
             var rootUri = ServerFixture.RootUri;

src/ProjectTemplates/Web.ProjectTemplates/content/BlazorServerWeb-CSharp/appsettings.Development.json

@@ -1,9 +1,10 @@
-{
+{
-  "Logging": {
+  "DetailedErrors": true,
-    "LogLevel": {
+  "Logging": {
+    "LogLevel": {
       "Default": "Information",
       "Microsoft": "Warning",
       "Microsoft.Hosting.Lifetime": "Information"
-    }
+    }
-  }
+  }
-}
+}