From db57a92a7e216b3984e3bb333f9c8664b088c9a4 Mon Sep 17 00:00:00 2001
From: Brendan Forster <brendan@github.com>
Date: Tue, 16 Jun 2015 22:29:02 +0930
Subject: [PATCH] sketching out the exception necessary when raising specific
 merge exceptions

---
 Octokit/Clients/PullRequestsClient.cs         | 19 ++++++-
 .../PullRequestMismatchException.cs           | 52 +++++++++++++++++++
 .../PullRequestNotMergeableException.cs       | 48 +++++++++++++++++
 Octokit/Octokit-Mono.csproj                   |  2 +
 Octokit/Octokit-MonoAndroid.csproj            |  4 +-
 Octokit/Octokit-Monotouch.csproj              |  2 +
 Octokit/Octokit-Portable.csproj               |  2 +
 Octokit/Octokit-netcore45.csproj              |  4 +-
 Octokit/Octokit.csproj                        |  2 +
 9 files changed, 132 insertions(+), 3 deletions(-)
 create mode 100644 Octokit/Exceptions/PullRequestMismatchException.cs
 create mode 100644 Octokit/Exceptions/PullRequestNotMergeableException.cs

diff --git a/Octokit/Clients/PullRequestsClient.cs b/Octokit/Clients/PullRequestsClient.cs
index 3cce9f30..fc1aeb35 100644
--- a/Octokit/Clients/PullRequestsClient.cs
+++ b/Octokit/Clients/PullRequestsClient.cs
@@ -115,7 +115,24 @@ namespace Octokit
             Ensure.ArgumentNotNullOrEmptyString(name, "name");
             Ensure.ArgumentNotNull(mergePullRequest, "mergePullRequest");
 
-            return ApiConnection.Put<PullRequestMerge>(ApiUrls.MergePullRequest(owner, name, number), mergePullRequest);
+            try
+            {
+                return ApiConnection.Put<PullRequestMerge>(ApiUrls.MergePullRequest(owner, name, number), mergePullRequest);
+            }
+            catch (ApiException ex)
+            {
+                if (ex.StatusCode == HttpStatusCode.MethodNotAllowed)
+                {
+                    throw new PullRequestNotMergeableException();
+                }
+
+                if (ex.StatusCode == HttpStatusCode.Conflict)
+                {
+                    throw new PullRequestMismatchException();
+                }
+
+                throw;
+            }
         }
 
         /// <summary>
diff --git a/Octokit/Exceptions/PullRequestMismatchException.cs b/Octokit/Exceptions/PullRequestMismatchException.cs
new file mode 100644
index 00000000..8a77d6dc
--- /dev/null
+++ b/Octokit/Exceptions/PullRequestMismatchException.cs
@@ -0,0 +1,52 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace Octokit
+{
+    /// <summary>
+    /// Represents an error that occurs when the specified SHA
+    /// doesn't match the current pull request's HEAD
+    /// </summary>
+#if !NETFX_CORE
+    [Serializable]
+#endif
+    public class PullRequestMismatchException : Exception
+    {
+        public PullRequestMismatchException()
+            : base("The merge operation specified a SHA which didn't match " +
+                   "the SHA of the pull request's HEAD")
+        {
+        }
+
+        public PullRequestMismatchException(string message)
+            : base(message)
+        {
+        }
+
+
+        public PullRequestMismatchException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+#if !NETFX_CORE
+        /// <summary>
+        /// Constructs an instance of PullRequestNotMergeableException.
+        /// </summary>
+        /// <param name="info">
+        /// The <see cref="SerializationInfo"/> that holds the
+        /// serialized object data about the exception being thrown.
+        /// </param>
+        /// <param name="context">
+        /// The <see cref="StreamingContext"/> that contains
+        /// contextual information about the source or destination.
+        /// </param>
+        protected PullRequestMismatchException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+#endif
+    }
+
+
+}
diff --git a/Octokit/Exceptions/PullRequestNotMergeableException.cs b/Octokit/Exceptions/PullRequestNotMergeableException.cs
new file mode 100644
index 00000000..e24c2d36
--- /dev/null
+++ b/Octokit/Exceptions/PullRequestNotMergeableException.cs
@@ -0,0 +1,48 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace Octokit
+{
+    /// <summary>
+    /// Represents an error that occurs when the pull request is in an
+    /// unmergeable state
+    /// </summary>
+#if !NETFX_CORE
+    [Serializable]
+#endif
+    public class PullRequestNotMergeableException : Exception
+    {
+        public PullRequestNotMergeableException()
+            : base("The pull request is not in a mergeable state")
+        {
+        }
+
+        public PullRequestNotMergeableException(string message)
+            : base(message)
+        {
+        }
+
+        public PullRequestNotMergeableException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+#if !NETFX_CORE
+        /// <summary>
+        /// Constructs an instance of PullRequestNotMergeableException.
+        /// </summary>
+        /// <param name="info">
+        /// The <see cref="SerializationInfo"/> that holds the
+        /// serialized object data about the exception being thrown.
+        /// </param>
+        /// <param name="context">
+        /// The <see cref="StreamingContext"/> that contains
+        /// contextual information about the source or destination.
+        /// </param>
+        protected PullRequestNotMergeableException(SerializationInfo info, StreamingContext context)
+            : base(info, context)
+        {
+        }
+#endif
+    }
+}
diff --git a/Octokit/Octokit-Mono.csproj b/Octokit/Octokit-Mono.csproj
index 3d6206fc..7c25f716 100644
--- a/Octokit/Octokit-Mono.csproj
+++ b/Octokit/Octokit-Mono.csproj
@@ -403,6 +403,8 @@
     <Compile Include="Http\IApiInfoProvider.cs" />
     <Compile Include="Models\Response\Meta.cs" />
     <Compile Include="Models\Common\Committer.cs" />
+    <Compile Include="Exceptions\PullRequestNotMergeableException.cs" />
+    <Compile Include="Exceptions\PullRequestMismatchException.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
 </Project>
diff --git a/Octokit/Octokit-MonoAndroid.csproj b/Octokit/Octokit-MonoAndroid.csproj
index ea68c7d3..97b56f7b 100644
--- a/Octokit/Octokit-MonoAndroid.csproj
+++ b/Octokit/Octokit-MonoAndroid.csproj
@@ -411,6 +411,8 @@
     <Compile Include="Http\IApiInfoProvider.cs" />
     <Compile Include="Models\Response\Meta.cs" />
     <Compile Include="Models\Common\Committer.cs" />
+    <Compile Include="Exceptions\PullRequestNotMergeableException.cs" />
+    <Compile Include="Exceptions\PullRequestMismatchException.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Novell\Novell.MonoDroid.CSharp.targets" />
-</Project>
\ No newline at end of file
+</Project>
diff --git a/Octokit/Octokit-Monotouch.csproj b/Octokit/Octokit-Monotouch.csproj
index 7b228d6d..cd135963 100644
--- a/Octokit/Octokit-Monotouch.csproj
+++ b/Octokit/Octokit-Monotouch.csproj
@@ -407,6 +407,8 @@
     <Compile Include="Http\IApiInfoProvider.cs" />
     <Compile Include="Models\Response\Meta.cs" />
     <Compile Include="Models\Common\Committer.cs" />
+    <Compile Include="Exceptions\PullRequestNotMergeableException.cs" />
+    <Compile Include="Exceptions\PullRequestMismatchException.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.MonoTouch.CSharp.targets" />
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
diff --git a/Octokit/Octokit-Portable.csproj b/Octokit/Octokit-Portable.csproj
index 28280e54..c5f57eb6 100644
--- a/Octokit/Octokit-Portable.csproj
+++ b/Octokit/Octokit-Portable.csproj
@@ -400,6 +400,8 @@
     <Compile Include="Http\IApiInfoProvider.cs" />
     <Compile Include="Models\Response\Meta.cs" />
     <Compile Include="Models\Common\Committer.cs" />
+    <Compile Include="Exceptions\PullRequestNotMergeableException.cs" />
+    <Compile Include="Exceptions\PullRequestMismatchException.cs" />
   </ItemGroup>
   <ItemGroup>
     <CodeAnalysisDictionary Include="..\CustomDictionary.xml">
diff --git a/Octokit/Octokit-netcore45.csproj b/Octokit/Octokit-netcore45.csproj
index 6f98071f..8bf0101a 100644
--- a/Octokit/Octokit-netcore45.csproj
+++ b/Octokit/Octokit-netcore45.csproj
@@ -404,6 +404,8 @@
     <Compile Include="Http\IApiInfoProvider.cs" />
     <Compile Include="Models\Response\Meta.cs" />
     <Compile Include="Models\Common\Committer.cs" />
+    <Compile Include="Exceptions\PullRequestNotMergeableException.cs" />
+    <Compile Include="Exceptions\PullRequestMismatchException.cs" />
   </ItemGroup>
   <ItemGroup>
     <CodeAnalysisDictionary Include="..\CustomDictionary.xml">
@@ -418,4 +420,4 @@
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
\ No newline at end of file
+</Project>
diff --git a/Octokit/Octokit.csproj b/Octokit/Octokit.csproj
index 3708c95b..46462ba3 100644
--- a/Octokit/Octokit.csproj
+++ b/Octokit/Octokit.csproj
@@ -72,6 +72,8 @@
     <Compile Include="Clients\UserKeysClient.cs" />
     <Compile Include="Clients\RepositoryContentsClient.cs" />
     <Compile Include="Exceptions\PrivateRepositoryQuotaExceededException.cs" />
+    <Compile Include="Exceptions\PullRequestMismatchException.cs" />
+    <Compile Include="Exceptions\PullRequestNotMergeableException.cs" />
     <Compile Include="Exceptions\RepositoryExistsException.cs" />
     <Compile Include="Exceptions\RepositoryFormatException.cs" />
     <Compile Include="Exceptions\TwoFactorAuthorizationException.cs" />