improved dispatch exception to indicate which values are missing

Author: Mpdreamz

Diff for: src/CodeGeneration/CodeGeneration.LowLevelClient/Views/_LowLevelDispatch.Generated.cshtml

@@ -18,17 +18,6 @@ namespace Nest
 	///<summary>This dispatches highlevel requests into the proper lowlevel client overload method</summary>
 	internal partial class LowLevelDispatch
 	{
-		internal static ElasticsearchClientException InvalidDispatch(string apiCall, IRequest provided, HttpMethod[] methods, params string[] endpoints)
-		{
-			var sb = new StringBuilder();
-			sb.AppendLine($"Dispatching {apiCall}() from NEST into to Elasticsearch.NET failed");
-			sb.AppendLine($"Received a request marked as {provided.HttpMethod.GetStringValue()}");
-			sb.AppendLine($"This endpoint accepts {string.Join(",", methods.Select(p=>p.GetStringValue()))}");
-			sb.AppendLine($"The request might not have enough information provided to make any of these endpoints:");
-			foreach (var endpoint in endpoints)
-				sb.AppendLine($"  - {endpoint}");
-			return new ElasticsearchClientException(sb.ToString());
-		}
 
 	@foreach (var kv in model.Endpoints)
 	{

Diff for: src/Nest/CommonAbstractions/LowLevelDispatch/LowLevelDispatch.cs

@@ -1,4 +1,7 @@
-using System.Linq;
+using System;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
 using Elasticsearch.Net;
 
 namespace Nest
@@ -12,8 +15,53 @@ public LowLevelDispatch(IElasticLowLevelClient rawElasticClient)
 			this._lowLevel = rawElasticClient;
 		}
 
-		internal bool AllSet(params string[] pathVariables) => pathVariables.All(p => !p.IsNullOrEmpty()) && !pathVariables.All(p=>p=="_all");
+		internal bool AllSet(params string[] pathVariables) => pathVariables.All(p => !p.IsNullOrEmpty()) && !pathVariables.All(p => p == "_all");
+
+		internal bool AllSet(params IUrlParameter[] pathVariables) => pathVariables.All(p => p != null);
+
+		internal static Exception InvalidDispatch(string apiCall, IRequest provided, HttpMethod[] methods, params string[] endpoints)
+		{
+			var sb = new StringBuilder();
+			sb.AppendLine($"Dispatching {apiCall}() from NEST into to Elasticsearch.NET failed");
+			sb.AppendLine($"Received a request marked as {provided.HttpMethod.GetStringValue()}");
+			sb.AppendLine($"This endpoint accepts {string.Join(",", methods.Select(p=>p.GetStringValue()))}");
+			sb.AppendLine($"The request might not have enough information provided to make any of these endpoints:");
+			foreach (var endpoint in endpoints)
+				sb.AppendLine($"  - {PrettyPrintEndpoint(provided, endpoint)}");
+
+			return new ArgumentException(sb.ToString());
+		}
+
+		private static Regex ReplaceParams = new Regex(@"\{(.+?)\}");
+
+		internal static string PrettyPrintEndpoint(IRequest request, string endpoint)
+		{
+			var pretty = ReplaceParams.Replace(endpoint, (m) =>
+			{
+				var key = m.Groups[1].Value.ToLowerInvariant(); 
+				switch(key)
+				{
+					case "index" :  return PrettyParam(key, request.RouteValues.Index);
+					case "name" :  return PrettyParam(key, request.RouteValues.Name);
+					case "feature" :  return PrettyParam(key, request.RouteValues.Feature);
+					case "field" :  return PrettyParam(key, request.RouteValues.Field);
+					case "fields" :  return PrettyParam(key, request.RouteValues.Fields);
+					case "id" :  return PrettyParam(key, request.RouteValues.Id);
+					case "index_metric" :  return PrettyParam(key, request.RouteValues.IndexMetric);
+					case "lang" :  return PrettyParam(key, request.RouteValues.Lang);
+					case "metric" :  return PrettyParam(key, request.RouteValues.Metric);
+					case "node_id" :  return PrettyParam(key, request.RouteValues.NodeId);
+					case "repository" :  return PrettyParam(key, request.RouteValues.Repository);
+					case "scroll_id" :  return PrettyParam(key, request.RouteValues.ScrollId);
+					case "snapshot" :  return PrettyParam(key, request.RouteValues.Snapshot);
+					case "type" :  return PrettyParam(key, request.RouteValues.Type);
+					default:  return PrettyParam(key, "<Unknown route variable>");
+				}
+			});
+			return pretty;
+		}
+
+		private static string PrettyParam(string key, string value) => $"{{{key}={(value.IsNullOrEmpty() ? "<NULL>" : value)}}}";
 
-        internal bool AllSet(params IUrlParameter[] pathVariables) => pathVariables.All(p => p != null);
 	}
 }

Diff for: src/Nest/_Generated/_LowLevelDispatch.generated.cs

@@ -15,18 +15,6 @@ namespace Nest
 	///<summary>This dispatches highlevel requests into the proper lowlevel client overload method</summary>
 	internal partial class LowLevelDispatch
 	{
-		internal static ElasticsearchClientException InvalidDispatch(string apiCall, IRequest provided, HttpMethod[] methods, params string[] endpoints)
-		{
-			var sb = new StringBuilder();
-			sb.AppendLine($"Dispatching {apiCall}() from NEST into to Elasticsearch.NET failed");
-			sb.AppendLine($"Received a request marked as {provided.HttpMethod.GetStringValue()}");
-			sb.AppendLine($"This endpoint accepts {string.Join(",", methods.Select(p=>p.GetStringValue()))}");
-			sb.AppendLine($"The request might not have enough information provided to make any of these endpoints:");
-			foreach (var endpoint in endpoints)
-				sb.AppendLine($"  - {endpoint}");
-			return new ElasticsearchClientException(sb.ToString());
-		}
-
 		internal ElasticsearchResponse<T> BulkDispatch<T>(IRequest<BulkRequestParameters> p , PostData<object> body) where T : class
 		{
 			switch(p.HttpMethod)

Diff for: src/Tests/ClientConcepts/Exceptions/ExceptionTests.cs

@@ -83,5 +83,17 @@ public void ClientTestWhenThrowExceptionsDisabled()
 #endif
 			response.CallDetails.ServerError.Should().BeNull();
 		}
+
+		[U]
+		public void DispatchIndicatesMissingRouteValues()
+		{
+			var settings = new ConnectionSettings(new Uri("http://doesntexist:9200"));
+			var client = new ElasticClient(settings);
+			
+			Action dispatch = () => client.Index(new Project());
+			var ce = dispatch.ShouldThrow<ArgumentException>();
+			ce.Should().NotBeNull();
+			ce.Which.Message.Should().Contain("index=<NULL>");
+		}
 	}
 }