Added requestBodyEmptyContent setting for rest client, Added TryParseError for rest implementations to check for error with success status code

CryptoExchange.Net/CryptoExchange.Net.csproj

@@ -6,12 +6,12 @@
     <PackageId>CryptoExchange.Net</PackageId>
     <Authors>JKorf</Authors>
     <Description>A base package for implementing cryptocurrency exchange API's</Description>
-    <PackageVersion>3.0.7</PackageVersion>
+    <PackageVersion>3.0.8</PackageVersion>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
     <PackageProjectUrl>https://github.com/JKorf/CryptoExchange.Net</PackageProjectUrl>
     <NeutralLanguage>en</NeutralLanguage>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
-    <PackageReleaseNotes>3.0.7 - Added error debug output, Fix for unsubscribe causing possible deadlock</PackageReleaseNotes>
+    <PackageReleaseNotes>3.0.8 - Added empty body content setting, added TryParseError virtual method</PackageReleaseNotes>
     <Nullable>enable</Nullable>
     <LangVersion>8.0</LangVersion>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>

CryptoExchange.Net/CryptoExchange.Net.xml

@@ -2112,6 +2112,11 @@
             Request body content type
             </summary>
         </member>
+        <member name="F:CryptoExchange.Net.RestClient.manualParseError">
+            <summary>
+            Whether or not we need to manually parse an error instead of relying on the http status code
+            </summary>
+        </member>
         <member name="F:CryptoExchange.Net.RestClient.arraySerialization">
             <summary>
             How to serialize array parameters
@@ -2188,6 +2193,14 @@
             <param name="cancellationToken">Cancellation token</param>
             <returns></returns>
         </member>
+        <member name="M:CryptoExchange.Net.RestClient.TryParseError(Newtonsoft.Json.Linq.JToken)">
+            <summary>
+            Can be used to parse an error even though response status indicates success. Some apis always return 200 OK, even though there is an error.
+            This can be used together with ManualParseError to check if it is an error before deserializing to an object
+            </summary>
+            <param name="data">Received data</param>
+            <returns>Null if not an error, Error otherwise</returns>
+        </member>
         <member name="M:CryptoExchange.Net.RestClient.ConstructRequest(System.Uri,System.Net.Http.HttpMethod,System.Collections.Generic.Dictionary{System.String,System.Object},System.Boolean)">
             <summary>
             Creates a request object
@@ -2926,5 +2939,148 @@
         <member name="M:CryptoExchange.Net.Sockets.WebsocketFactory.CreateWebsocket(CryptoExchange.Net.Logging.Log,System.String,System.Collections.Generic.IDictionary{System.String,System.String},System.Collections.Generic.IDictionary{System.String,System.String})">
             <inheritdoc />
         </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.AllowNullAttribute">
+            <summary>
+                Specifies that <see langword="null"/> is allowed as an input even if the
+                corresponding type disallows it.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.AllowNullAttribute.#ctor">
+            <summary>
+                Initializes a new instance of the <see cref="T:System.Diagnostics.CodeAnalysis.AllowNullAttribute"/> class.
+            </summary>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.DisallowNullAttribute">
+            <summary>
+                Specifies that <see langword="null"/> is disallowed as an input even if the
+                corresponding type allows it.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.DisallowNullAttribute.#ctor">
+            <summary>
+                Initializes a new instance of the <see cref="T:System.Diagnostics.CodeAnalysis.DisallowNullAttribute"/> class.
+            </summary>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.DoesNotReturnAttribute">
+            <summary>
+                Specifies that a method that will never return under any circumstance.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.DoesNotReturnAttribute.#ctor">
+            <summary>
+                Initializes a new instance of the <see cref="T:System.Diagnostics.CodeAnalysis.DoesNotReturnAttribute"/> class.
+            </summary>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.DoesNotReturnIfAttribute">
+            <summary>
+                Specifies that the method will not return if the associated <see cref="T:System.Boolean"/>
+                parameter is passed the specified value.
+            </summary>
+        </member>
+        <member name="P:System.Diagnostics.CodeAnalysis.DoesNotReturnIfAttribute.ParameterValue">
+            <summary>
+                Gets the condition parameter value.
+                Code after the method is considered unreachable by diagnostics if the argument
+                to the associated parameter matches this value.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.DoesNotReturnIfAttribute.#ctor(System.Boolean)">
+            <summary>
+                Initializes a new instance of the <see cref="T:System.Diagnostics.CodeAnalysis.DoesNotReturnIfAttribute"/>
+                class with the specified parameter value.
+            </summary>
+            <param name="parameterValue">
+                The condition parameter value.
+                Code after the method is considered unreachable by diagnostics if the argument
+                to the associated parameter matches this value.
+            </param>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.MaybeNullAttribute">
+            <summary>
+                Specifies that an output may be <see langword="null"/> even if the
+                corresponding type disallows it.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.MaybeNullAttribute.#ctor">
+            <summary>
+                Initializes a new instance of the <see cref="T:System.Diagnostics.CodeAnalysis.MaybeNullAttribute"/> class.
+            </summary>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute">
+            <summary>
+                Specifies that when a method returns <see cref="P:System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute.ReturnValue"/>, 
+                the parameter may be <see langword="null"/> even if the corresponding type disallows it.
+            </summary>
+        </member>
+        <member name="P:System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute.ReturnValue">
+            <summary>
+                Gets the return value condition.
+                If the method returns this value, the associated parameter may be <see langword="null"/>.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.MaybeNullWhenAttribute.#ctor(System.Boolean)">
+            <summary>
+                 Initializes the attribute with the specified return value condition.
+            </summary>
+            <param name="returnValue">
+                The return value condition.
+                If the method returns this value, the associated parameter may be <see langword="null"/>.
+            </param>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.NotNullAttribute">
+            <summary>
+                Specifies that an output is not <see langword="null"/> even if the
+                corresponding type allows it.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.NotNullAttribute.#ctor">
+            <summary>
+                Initializes a new instance of the <see cref="T:System.Diagnostics.CodeAnalysis.NotNullAttribute"/> class.
+            </summary>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.NotNullIfNotNullAttribute">
+            <summary>
+                Specifies that the output will be non-<see langword="null"/> if the
+                named parameter is non-<see langword="null"/>.
+            </summary>
+        </member>
+        <member name="P:System.Diagnostics.CodeAnalysis.NotNullIfNotNullAttribute.ParameterName">
+            <summary>
+                Gets the associated parameter name.
+                The output will be non-<see langword="null"/> if the argument to the
+                parameter specified is non-<see langword="null"/>.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.NotNullIfNotNullAttribute.#ctor(System.String)">
+            <summary>
+                Initializes the attribute with the associated parameter name.
+            </summary>
+            <param name="parameterName">
+                The associated parameter name.
+                The output will be non-<see langword="null"/> if the argument to the
+                parameter specified is non-<see langword="null"/>.
+            </param>
+        </member>
+        <member name="T:System.Diagnostics.CodeAnalysis.NotNullWhenAttribute">
+            <summary>
+                Specifies that when a method returns <see cref="P:System.Diagnostics.CodeAnalysis.NotNullWhenAttribute.ReturnValue"/>,
+                the parameter will not be <see langword="null"/> even if the corresponding type allows it.
+            </summary>
+        </member>
+        <member name="P:System.Diagnostics.CodeAnalysis.NotNullWhenAttribute.ReturnValue">
+            <summary>
+                Gets the return value condition.
+                If the method returns this value, the associated parameter will not be <see langword="null"/>.
+            </summary>
+        </member>
+        <member name="M:System.Diagnostics.CodeAnalysis.NotNullWhenAttribute.#ctor(System.Boolean)">
+            <summary>
+                Initializes the attribute with the specified return value condition.
+            </summary>
+            <param name="returnValue">
+                The return value condition.
+                If the method returns this value, the associated parameter will not be <see langword="null"/>.
+            </param>
+        </member>
     </members>
 </doc>

CryptoExchange.Net/RestClient.cs

@@ -6,6 +6,7 @@ using System.Linq;
 using System.Net.Http;
 using System.Net.NetworkInformation;
 using System.Net.Sockets;
+using System.Security.Cryptography;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
@@ -39,11 +40,21 @@ namespace CryptoExchange.Net
         /// </summary>
         protected RequestBodyFormat requestBodyFormat = RequestBodyFormat.Json;
 
+        /// <summary>
+        /// Whether or not we need to manually parse an error instead of relying on the http status code
+        /// </summary>
+        protected bool manualParseError = false;
+
         /// <summary>
         /// How to serialize array parameters
         /// </summary>
         protected ArrayParametersSerialization arraySerialization = ArrayParametersSerialization.Array;
 
+        /// <summary>
+        /// What request body should be when no data is send
+        /// </summary>
+        protected string requestBodyEmptyContent = "{}";
+
         /// <summary>
         /// Timeout for requests
         /// </summary>
@@ -205,11 +216,32 @@ namespace CryptoExchange.Net
                 var responseStream = await response.GetResponseStream().ConfigureAwait(false);
                 if (response.IsSuccessStatusCode)
                 {
-                    var desResult = await Deserialize<T>(responseStream).ConfigureAwait(false);
+                    if (manualParseError)
-                    responseStream.Close();
+                    {
-                    response.Close();
+                        using var reader = new StreamReader(responseStream);
+                        var data = await reader.ReadToEndAsync().ConfigureAwait(false);
+                        responseStream.Close();
+                        response.Close();
+                        log.Write(LogVerbosity.Debug, $"Data received: {data}");
 
-                    return new WebCallResult<T>(statusCode, headers, desResult.Data, desResult.Error);
+                        var parseResult = ValidateJson(data);
+                        if (!parseResult.Success)
+                            return WebCallResult<T>.CreateErrorResult(response.StatusCode, response.ResponseHeaders, new ServerError(data));
+                        var error = await TryParseError(parseResult.Data);
+                        if(error != null)
+                            return WebCallResult<T>.CreateErrorResult(response.StatusCode, response.ResponseHeaders, error);
+
+                        var deserializeResult = Deserialize<T>(parseResult.Data);
+                        return new WebCallResult<T>(response.StatusCode, response.ResponseHeaders, deserializeResult.Data, deserializeResult.Error);
+                    }
+                    else
+                    {
+                        var desResult = await Deserialize<T>(responseStream).ConfigureAwait(false);
+                        responseStream.Close();
+                        response.Close();
+
+                        return new WebCallResult<T>(statusCode, headers, desResult.Data, desResult.Error);
+                    }
                 }
                 else
                 {
@@ -244,6 +276,17 @@ namespace CryptoExchange.Net
             }
         }
 
+        /// <summary>
+        /// Can be used to parse an error even though response status indicates success. Some apis always return 200 OK, even though there is an error.
+        /// This can be used together with ManualParseError to check if it is an error before deserializing to an object
+        /// </summary>
+        /// <param name="data">Received data</param>
+        /// <returns>Null if not an error, Error otherwise</returns>
+        protected virtual Task<ServerError?> TryParseError(JToken data)
+        {
+            return Task.FromResult<ServerError?>(null);
+        }
+
         /// <summary>
         /// Creates a request object
         /// </summary>
@@ -280,7 +323,7 @@ namespace CryptoExchange.Net
                 if(parameters?.Any() == true)
                     WriteParamBody(request, parameters, contentType);
                 else
-                    request.SetContent("{}", contentType);
+                    request.SetContent(requestBodyEmptyContent, contentType);
             }
 
             return request;

README.md

@@ -194,6 +194,10 @@ The order book will automatically reconnect when the connection is lost and resy
 To stop synchronizing an order book use the `Stop` method.
 
 ## Release notes
+* Version 3.0.8 - 02 Jun 2020
+	* Added requestBodyEmptyContent setting for rest client
+	* Added TryParseError for rest implementations to check for error with success status code
+
 * Version 3.0.7 - 20 May 2020
     * Added error debug output
     * Fix for unsubscribe causing possible deadlock