Refactor error handling. Add test for checking for bad username / password scenario

5 files changed, 98 insertions, 62 deletions

diff --git a/SendGrid/SendGridMail/Mail.csproj b/SendGrid/SendGridMail/Mail.csproj
index b1f8f84..998226f 100644
--- a/SendGrid/SendGridMail/Mail.csproj
+++ b/SendGrid/SendGridMail/Mail.csproj
@@ -103,6 +103,7 @@
     <Compile Include="ISendGrid.cs" />

     <Compile Include="Properties\AssemblyInfo.cs" />

     <Compile Include="SendGrid.cs" />

+    <Compile Include="Transport\ErrorChecker.cs" />

     <Compile Include="Transport\ITransport.cs" />

     <Compile Include="Transport\Web.cs" />

   </ItemGroup>

diff --git a/SendGrid/SendGridMail/Transport/ErrorChecker.cs b/SendGrid/SendGridMail/Transport/ErrorChecker.cs
new file mode 100644
index 0000000..035d2b8
--- /dev/null
+++ b/SendGrid/SendGridMail/Transport/ErrorChecker.cs
@@ -0,0 +1,57 @@
+namespace SendGrid
+{
+    using System;
+    using System.IO;
+    using System.Net;
+    using System.Net.Http;
+    using System.Threading.Tasks;
+    using System.Xml;
+
+    using Exceptions;
+
+    public static class ErrorChecker
+    {
+        public static void CheckForErrors(HttpResponseMessage response)
+        {
+            CheckForErrors(response, response.Content.ReadAsStreamAsync().Result);
+        }
+
+        public static async Task CheckForErrorsAsync(HttpResponseMessage response)
+        {
+            CheckForErrors(response, await response.Content.ReadAsStreamAsync());
+        }
+
+        private static void CheckForErrors(HttpResponseMessage response, Stream stream)
+        {
+            if (response.StatusCode != HttpStatusCode.OK)
+            {
+                using (var reader = XmlReader.Create(stream))
+                {
+                    while (reader.Read())
+                    {
+                        if (!reader.IsStartElement())
+                        {
+                            continue;
+                        }
+
+                        switch (reader.Name)
+                        {
+                            case "result":
+                                continue;
+                            case "message":
+                                continue;
+                            case "errors":
+                                reader.ReadToFollowing("error");
+                                var message = reader.ReadElementContentAsString("error", reader.NamespaceURI);
+                                throw new InvalidApiRequestException(response.StatusCode, new[] { message }, response.ReasonPhrase);
+                            case "error":
+                                throw new ProtocolViolationException();
+                            default:
+                                throw new ArgumentException("Unknown element: " + reader.Name);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/SendGrid/SendGridMail/Transport/Web.cs b/SendGrid/SendGridMail/Transport/Web.cs
index 7abf104..a125833 100644
--- a/SendGrid/SendGridMail/Transport/Web.cs
+++ b/SendGrid/SendGridMail/Transport/Web.cs
@@ -66,7 +66,7 @@ namespace SendGrid
 			AttachFormParams(message, content);

 			AttachFiles(message, content);

 			var response = client.PostAsync(Endpoint + ".xml", content).Result;

-			CheckForErrors(response);

+			ErrorChecker.CheckForErrors(response);

 		}

 

 		/// <summary>

@@ -87,7 +87,7 @@ namespace SendGrid
 			AttachFormParams(message, content);

 			AttachFiles(message, content);

 			var response = await client.PostAsync(Endpoint + ".xml", content);

-			await CheckForErrorsAsync(response);

+            await ErrorChecker.CheckForErrorsAsync(response);

 		}

 

 	    #region Support Methods

@@ -136,66 +136,8 @@ namespace SendGrid
 			}

 		}

 

-		private static void CheckForErrors(HttpResponseMessage response)

-		{

-			var content = response.Content.ReadAsStreamAsync().Result;

-			var errors = GetErrorsInResponse(content);

-

-			// API error

-			if (errors.Any())

-				throw new InvalidApiRequestException(response.StatusCode, errors, response.ReasonPhrase);

-

-			// Other error

-			if (response.StatusCode != HttpStatusCode.OK)

-				FindErrorsInResponse(content);

-		}

-

-		private static void FindErrorsInResponse(Stream content)

-		{

-			using (var reader = XmlReader.Create(content))

-			{

-				while (reader.Read())

-				{

-					if (!reader.IsStartElement()) continue;

-					switch (reader.Name)

-					{

-						case "result":

-							break;

-						case "message": // success

-							if (reader.ReadToNextSibling("errors"))

-								throw new ProtocolViolationException();

-							return;

-						case "error": // failure

-							throw new ProtocolViolationException();

-						default:

-							throw new ArgumentException("Unknown element: " + reader.Name);

-					}

-				}

-			}

-		}

-

-		private static string[] GetErrorsInResponse(Stream content)

-		{

-			var xmlDoc = new XmlDocument();

-			xmlDoc.Load(content);

-			return (from XmlNode errorNode in xmlDoc.SelectNodes("//error") select errorNode.InnerText).ToArray();

-		}

-

-		private static async Task CheckForErrorsAsync(HttpResponseMessage response)

-		{

-			var content = await response.Content.ReadAsStreamAsync();

-

-		    var errors = GetErrorsInResponse(content);

-

-            // API error

-            if (errors.Any())

-                throw new InvalidApiRequestException(response.StatusCode, errors, response.ReasonPhrase);

-

-            // Other error

-            if (response.StatusCode != HttpStatusCode.OK)

-                FindErrorsInResponse(content);

-		}

-

+		

+        

 		internal List<KeyValuePair<String, String>> FetchFormParams(ISendGrid message)

 		{

 			var result = new List<KeyValuePair<string, string>>

diff --git a/SendGrid/Tests/Tests.csproj b/SendGrid/Tests/Tests.csproj
index 7a62424..2dba458 100644
--- a/SendGrid/Tests/Tests.csproj
+++ b/SendGrid/Tests/Tests.csproj
@@ -62,10 +62,12 @@
     <Reference Include="System" />

     <Reference Include="System.Core" />

     <Reference Include="System.Net" />

+    <Reference Include="System.Net.Http" />

   </ItemGroup>

   <ItemGroup>

     <Compile Include="Properties\AssemblyInfo.cs" />

     <Compile Include="TestSendgrid.cs" />

+    <Compile Include="Transport\TestErrorChecker.cs" />

     <Compile Include="Transport\TestWebApi.cs" />

   </ItemGroup>

   <ItemGroup>

diff --git a/SendGrid/Tests/Transport/TestErrorChecker.cs b/SendGrid/Tests/Transport/TestErrorChecker.cs
new file mode 100644
index 0000000..f178064
--- /dev/null
+++ b/SendGrid/Tests/Transport/TestErrorChecker.cs
@@ -0,0 +1,34 @@
+namespace Transport
+{
+    #region Using Directives
+
+    using System;
+    using System.Net;
+    using System.Net.Http;
+
+    using Exceptions;
+
+    using NUnit.Framework;
+
+    using SendGrid;
+
+    #endregion
+
+    [TestFixture]
+    public class TestErrorChecker
+    {
+        private const string BadUsernameOrPasswordResponseMessage = "<result><message>error</message><errors><error>Bad username / password</error></errors></result>";
+
+        [Test]
+        [ExpectedException(typeof(InvalidApiRequestException))]
+        public void WhenHttpResponseContainsBadUserErrorItIsDetectedAndAInvalidApiRequestIsThrown()
+        {
+            var response = new HttpResponseMessage(HttpStatusCode.BadRequest)
+            {
+                Content = new StringContent(BadUsernameOrPasswordResponseMessage)
+            };
+
+            ErrorChecker.CheckForErrors(response);
+        }
+    }
+}
\ No newline at end of file