Added support for new -SkipDuplicate option in NuGet 5.1 (#85)

* Added support for new -SkipDuplicate option in NuGet 5.1

* removed empty line in NuGetODataController.cs

* DuplicatePackageException now extends Exception instead of InvalidOperationException

* Fixed test ServerPackageRepositoryAddPackageRejectsDuplicatesWithSemVer2 by replacing InvalidOperationException with DuplicatePackageException

* Added test PushDuplicatePackage

Author: jacksga

src/NuGet.Server.Core/Core/DuplicatePackageException.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace NuGet.Server.Core
+{
+    /// <summary>
+    /// This exception is thrown when trying to add a package in a version that already exists on the server 
+    /// and <see cref="NuGet.Server.Core.Infrastructure.ServerPackageRepository.AllowOverrideExistingPackageOnPush"/> is set to false.
+    /// </summary>
+    public class DuplicatePackageException : Exception
+    {
+        public DuplicatePackageException()
+        {
+        }
+
+        public DuplicatePackageException(string message) : base(message)
+        {
+        }
+
+        public DuplicatePackageException(string message, Exception innerException) : base(message, innerException)
+        {
+        }
+
+        protected DuplicatePackageException(SerializationInfo info, StreamingContext context) : base(info, context)
+        {
+        }
+    }
+}

src/NuGet.Server.Core/Infrastructure/ServerPackageRepository.cs

@@ -400,7 +400,7 @@ private bool CanPackageBeAddedWithoutLocking(IPackage package, bool shouldThrow)
 
                 if (shouldThrow)
                 {
-                    throw new InvalidOperationException(message);
+                    throw new DuplicatePackageException(message);
                 }
 
                 return false;

src/NuGet.Server.Core/NuGet.Server.Core.csproj

@@ -60,6 +60,7 @@
       <Link>HashCodeCombiner.cs</Link>
     </Compile>
     <Compile Include="Core\Constants.cs" />
+    <Compile Include="Core\DuplicatePackageException.cs" />
     <Compile Include="Core\FrameworkNameExtensions.cs" />
     <Compile Include="Core\NullFileSystem.cs" />
     <Compile Include="Core\PackageExtensions.cs" />

src/NuGet.Server.V2/Controllers/NuGetODataController.cs

@@ -403,8 +403,15 @@ public virtual async Task<HttpResponseMessage> UploadPackage(CancellationToken t
             HttpResponseMessage retValue;
             if (_authenticationService.IsAuthenticated(User, apiKey, package.Id))
             {
-                await _serverRepository.AddPackageAsync(package, token);
-                retValue = Request.CreateResponse(HttpStatusCode.Created);
+                try
+                {
+                    await _serverRepository.AddPackageAsync(package, token);
+                    retValue = Request.CreateResponse(HttpStatusCode.Created);
+                }
+                catch (DuplicatePackageException ex)
+                {
+                    retValue = CreateStringResponse(HttpStatusCode.Conflict, ex.Message);
+                }
             }
             else
             {

test/NuGet.Server.Core.Tests/ServerPackageRepositoryTest.cs

@@ -203,7 +203,7 @@ public async Task ServerPackageRepository_DuplicateAddAfterClearObservesOverride
                 }
                 else
                 {
-                    await Assert.ThrowsAsync<InvalidOperationException>(async () =>
+                    await Assert.ThrowsAsync<DuplicatePackageException>(async () =>
                         await serverRepository.AddPackageAsync(CreatePackage("test", "1.2"), Token));
                 }
             }
@@ -895,7 +895,7 @@ public async Task ServerPackageRepositoryAddPackageRejectsDuplicatesWithSemVer2(
                 await serverRepository.AddPackageAsync(CreatePackage("Foo", "1.0.0-beta.1+foo"), Token);
 
                 // Act & Assert
-                var actual = await Assert.ThrowsAsync<InvalidOperationException>(async () =>
+                var actual = await Assert.ThrowsAsync<DuplicatePackageException>(async () =>
                     await serverRepository.AddPackageAsync(CreatePackage("Foo", "1.0.0-beta.1+bar"), Token));
                 Assert.Equal(
                     "Package Foo 1.0.0-beta.1 already exists. The server is configured to not allow overwriting packages that already exist.",

test/NuGet.Server.Tests/IntegrationTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -135,6 +135,27 @@ public async Task FilterOnFramework()
             }
         }
 
+        [Fact]
+        public async Task PushDuplicatePackage()
+        {
+            // Arrange
+            using (var tc = new TestContext(_output))
+            {
+                string apiKey = "foobar";
+                tc.SetApiKey(apiKey);
+
+                var packagePath = Path.Combine(tc.TemporaryDirectory, "package.nupkg");
+                TestData.CopyResourceToPath(TestData.PackageResource, packagePath);
+
+                // Act & Assert
+                // 1. Push the package.
+                await tc.PushPackageAsync(apiKey, packagePath);
+
+                // 2. Push the package again expecting a 409 as the Package already exists.
+                await tc.PushPackageAsync(apiKey, packagePath, excepectedStatusCode: HttpStatusCode.Conflict);
+            }
+        }
+
         [Fact]
         public async Task PushPackageThenReadPackages()
         {
@@ -462,7 +483,7 @@ public MultipartContent GetFileUploadContent(params string[] paths)
                 return content;
             }
 
-            public async Task PushPackageAsync(string apiKey, string packagePath, string pushUrl = "/nuget")
+            public async Task PushPackageAsync(string apiKey, string packagePath, string pushUrl = "/nuget", HttpStatusCode excepectedStatusCode = HttpStatusCode.Created)
             {
                 using (var request = new HttpRequestMessage(HttpMethod.Put, pushUrl)
                 {
@@ -474,7 +495,7 @@ public async Task PushPackageAsync(string apiKey, string packagePath, string pus
                 })
                 using (var response = await Client.SendAsync(request))
                 {
-                    Assert.Equal(HttpStatusCode.Created, response.StatusCode);
+                    Assert.Equal(excepectedStatusCode, response.StatusCode);
                 }
             }