Add response mime type to response (#3198)

This commit is a backport of #3188 that adds the response mime type to ElasticsearchResponse.

Author: russcam

src/Elasticsearch.Net/Connection/HttpConnection-CoreFx.cs

@@ -36,14 +36,14 @@ public class HttpConnection : IConnection
 		protected readonly ConcurrentDictionary<int, HttpClient> Clients = new ConcurrentDictionary<int, HttpClient>();
 
 		private static readonly string CanNotUseStreamResponsesWithCurlHandler =
-				"Using Stream as TReturn does not work as expected on .NET core linux, because we can no longer guarantee this works it will be removed from the client in our 6.0 release"
+				"Using Stream as TReturn does not work as expected on .NET core linux. " +
+				"Because we can no longer guarantee this works it will be removed from the client in our 6.0 release"
 			;
 
 		private HttpClient GetClient(RequestData requestData)
 		{
 			var key = GetClientKey(requestData);
-			HttpClient client;
-			if (this.Clients.TryGetValue(key, out client)) return client;
+			if (this.Clients.TryGetValue(key, out var client)) return client;
 			lock (_lock)
 			{
 				client = this.Clients.GetOrAdd(key, h =>
@@ -64,8 +64,6 @@ private HttpClient GetClient(RequestData requestData)
 
 		public virtual ElasticsearchResponse<TReturn> Request<TReturn>(RequestData requestData) where TReturn : class
 		{
-			//TODO remove Stream response support in 6.0, closing the stream is sufficient on desktop/mono
-			//but not on .NET core on linux HttpClient which proxies to curl.
 			if (typeof(TReturn) == typeof(Stream) && ConnectionConfiguration.IsCurlHandler)
 				throw new Exception(CanNotUseStreamResponsesWithCurlHandler);
 
@@ -78,10 +76,11 @@ public virtual ElasticsearchResponse<TReturn> Request<TReturn>(RequestData reque
 				responseMessage = client.SendAsync(requestMessage).GetAwaiter().GetResult();
 				requestData.MadeItToResponse = true;
 				builder.StatusCode = (int) responseMessage.StatusCode;
-				IEnumerable<string> warnings;
-				if (responseMessage.Headers.TryGetValues("Warning", out warnings))
+				if (responseMessage.Headers.TryGetValues("Warning", out var warnings))
 					builder.DeprecationWarnings = warnings;
 
+				builder.ResponseMimeType = responseMessage.Content.Headers.ContentType?.MediaType;
+
 				if (responseMessage.Content != null)
 					builder.Stream = responseMessage.Content.ReadAsStreamAsync().GetAwaiter().GetResult();
 				// https://github.com/elastic/elasticsearch-net/issues/2311
@@ -107,8 +106,6 @@ public virtual ElasticsearchResponse<TReturn> Request<TReturn>(RequestData reque
 		public virtual async Task<ElasticsearchResponse<TReturn>> RequestAsync<TReturn>(RequestData requestData,
 			CancellationToken cancellationToken) where TReturn : class
 		{
-			//TODO remove Stream response support in 6.0, closing the stream is sufficient on desktop/mono
-			//but not on .NET core on linux HttpClient which proxies to curl.
 			if (typeof(TReturn) == typeof(Stream) && ConnectionConfiguration.IsCurlHandler)
 				throw new Exception(CanNotUseStreamResponsesWithCurlHandler);
 
@@ -121,10 +118,11 @@ public virtual async Task<ElasticsearchResponse<TReturn>> RequestAsync<TReturn>(
 				responseMessage = await client.SendAsync(requestMessage, cancellationToken).ConfigureAwait(false);
 				requestData.MadeItToResponse = true;
 				builder.StatusCode = (int) responseMessage.StatusCode;
-				IEnumerable<string> warnings;
-				if (responseMessage.Headers.TryGetValues("Warning", out warnings))
+				if (responseMessage.Headers.TryGetValues("Warning", out var warnings))
 					builder.DeprecationWarnings = warnings;
 
+				builder.ResponseMimeType = responseMessage.Content.Headers.ContentType?.MediaType;
+
 				if (responseMessage.Content != null)
 					builder.Stream = await responseMessage.Content.ReadAsStreamAsync().ConfigureAwait(false);
 				// https://github.com/elastic/elasticsearch-net/issues/2311
@@ -250,7 +248,7 @@ protected virtual HttpRequestMessage CreateRequestMessage(RequestData requestDat
 			else
 			{
 				// Set content in order to set a Content-Type header.
-				// Content gets diposed so can't be shared instance
+				// Content gets disposed so can't be shared instance
 				requestMessage.Content = new ByteArrayContent(new byte[0]);
 			}
 

src/Elasticsearch.Net/Responses/ElasticsearchResponse.cs

@@ -75,6 +75,8 @@ public class ElasticsearchResponse<T> : IApiCallDetails
 
 		public IEnumerable<string> DeprecationWarnings { get; internal set; } = Enumerable.Empty<string>();
 
+		public string ResponseMimeType { get; internal set; }
+
 		internal bool AllowAllStatusCodes { get; }
 
 		/// <summary>

src/Elasticsearch.Net/Transport/Pipeline/ResponseBuilder.cs

@@ -22,6 +22,7 @@ public class ResponseBuilder<TReturn>
 		public Exception Exception { get; set; }
 		public int? StatusCode { get; set; }
 		public Stream Stream { get; set; }
+		public string ResponseMimeType { get; set; } = RequestData.MimeType;
 
 		public IEnumerable<string> DeprecationWarnings { get; set; }
 
@@ -61,6 +62,7 @@ private ElasticsearchResponse<TReturn> Initialize(int? statusCode, Exception exc
 			response.HttpMethod = this._requestData.Method;
 			response.OriginalException = exception;
 			response.DeprecationWarnings = this.DeprecationWarnings ?? Enumerable.Empty<string>();
+			response.ResponseMimeType = this.ResponseMimeType;
 			return response;
 		}