From 8b13b3e5797dbe37444f99991100da0eb5c1b7a6 Mon Sep 17 00:00:00 2001
From: Daniel Plaisted <daplaist@microsoft.com>
Date: Fri, 5 May 2017 13:13:18 -0700
Subject: [PATCH] Fall back to tools restored for .NET Core 1.x if they haven't
 been restored for .NET Core 2.0

---
 .../ProjectToolsCommandResolver.cs            | 26 ++++++++-
 test/dotnet.Tests/PackagedCommandTests.cs     | 55 ++++++++++++++++++-
 2 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectToolsCommandResolver.cs b/src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectToolsCommandResolver.cs
index 7cd9a6113..8f952c950 100644
--- a/src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectToolsCommandResolver.cs
+++ b/src/Microsoft.DotNet.Cli.Utils/CommandResolution/ProjectToolsCommandResolver.cs
@@ -141,9 +141,33 @@ namespace Microsoft.DotNet.Cli.Utils
                 toolPackageFramework,
                 possiblePackageRoots);
 
+
+            //  NuGet restore in Visual Studio may restore for netcoreapp1.0.  So if that happens, fall back to
+            //  looking for a netcoreapp1.0 or netcoreapp1.1 tool restore.
             if (toolLockFile == null)
             {
-                return null;
+                if (toolPackageFramework.Framework == FrameworkConstants.FrameworkIdentifiers.NetCoreApp &&
+                    toolPackageFramework.Version >= new Version(2, 0, 0))
+                {
+                    foreach (var fallbackFramework in new [] { "netcoreapp1.1", "netcoreapp1.0"})
+                    {
+                        toolPackageFramework = NuGetFramework.Parse(fallbackFramework);
+                        toolLockFile = GetToolLockFile(
+                            toolLibraryRange,
+                            toolPackageFramework,
+                            possiblePackageRoots);
+
+                        if (toolLockFile != null)
+                        {
+                            break;
+                        }
+                    }
+                }
+
+                if (toolLockFile == null)
+                {
+                    return null;
+                }
             }
 
             Reporter.Verbose.WriteLine(string.Format(
diff --git a/test/dotnet.Tests/PackagedCommandTests.cs b/test/dotnet.Tests/PackagedCommandTests.cs
index bb75131d5..d5c83d97a 100644
--- a/test/dotnet.Tests/PackagedCommandTests.cs
+++ b/test/dotnet.Tests/PackagedCommandTests.cs
@@ -16,6 +16,7 @@ using Xunit.Abstractions;
 using Microsoft.Build.Construction;
 using System.Linq;
 using Microsoft.Build.Evaluation;
+using System.Xml.Linq;
 
 namespace Microsoft.DotNet.Tests
 {
@@ -161,10 +162,62 @@ namespace Microsoft.DotNet.Tests
                 .Execute(toolPrefersCLIRuntime ? "portable-v1-prefercli" : "portable-v1");
 
             result.Should().Pass()
-                .And.HaveStdOutContaining("I'm running on shared framework version 1.1.1!");    
+                .And.HaveStdOutContaining("I'm running on shared framework version 1.1.1!");
 
         }
 
+        [RequiresSpecificFrameworkFact("netcoreapp1.1")]
+        public void IfAToolHasNotBeenRestoredForNetCoreApp2_0ItFallsBackToNetCoreApp1_x()
+        {
+            string toolName = "dotnet-portable-v1";
+
+            var toolFolder = Path.Combine(new RepoDirectoriesProvider().NugetPackages,
+                                          ".tools",
+                                          toolName);
+
+            //  Other tests may have restored the tool for netcoreapp2.0, so delete its tools folder
+            if (Directory.Exists(toolFolder))
+            {
+                Directory.Delete(toolFolder, true);
+            }
+
+            var testInstance = TestAssets.Get("AppWithToolDependency")
+                .CreateInstance()
+                .WithSourceFiles()
+                .WithNuGetConfig(new RepoDirectoriesProvider().TestPackages);
+
+            testInstance = testInstance.WithProjectChanges(project =>
+            {
+                var ns = project.Root.Name.Namespace;
+
+                //  Remove reference to tool that won't restore on 1.x
+                project.Descendants(ns + "DotNetCliToolReference")
+                    .Where(tr => tr.Attribute("Include").Value == "dotnet-PreferCliRuntime")
+                    .Remove();
+
+                var toolReference = project.Descendants(ns + "DotNetCliToolReference")
+                    .Where(tr => tr.Attribute("Include").Value == "dotnet-portable")
+                    .Single();
+
+                toolReference.Attribute("Include").Value = toolName;
+
+                //  Restore tools for .NET Core 1.1
+                project.Root.Element(ns + "PropertyGroup")
+                    .Add(new XElement(ns + "DotnetCliToolTargetFramework", "netcoreapp1.1"));
+
+            });
+
+            testInstance = testInstance.WithRestoreFiles();
+
+            var result =
+                    new DotnetCommand(DotnetUnderTest.WithBackwardsCompatibleRuntimes)
+                    .WithWorkingDirectory(testInstance.Root)
+                    .Execute("portable-v1");
+
+            result.Should().Pass()
+                .And.HaveStdOutContaining("I'm running on shared framework version 1.1.1!");
+        }
+
         [Fact]
         public void CanInvokeToolWhosePackageNameIsDifferentFromDllName()
         {