Add API for multi-tfm projects (#184)

Project builder supports auto-detecting the framework

src/Microsoft.Extensions.ProjectModel.Sources/MsBuild/MsBuildProjectContext.cs

@@ -35,7 +35,19 @@ namespace Microsoft.Extensions.ProjectModel
         public string ProjectName => FindProperty("ProjectName") ?? _name;
         public string Configuration { get; }
 
-        public NuGetFramework TargetFramework => NuGetFramework.Parse(FindProperty("NuGetTargetMoniker"));
+        public NuGetFramework TargetFramework
+        {
+            get
+            {
+                var tfm = FindProperty("NuGetTargetMoniker") ?? FindProperty("TargetFramework");
+                if (tfm == null)
+                {
+                    return null;
+                }
+                return NuGetFramework.Parse(tfm);
+            }
+        }
+
         public bool IsClassLibrary => FindProperty("OutputType").Equals("Library", StringComparison.OrdinalIgnoreCase);
 
         // TODO get from actual properties according to TFM

src/Microsoft.Extensions.ProjectModel.Sources/MsBuild/MsBuildProjectContextBuilder.cs

@@ -14,6 +14,7 @@ using Microsoft.Extensions.FileProviders;
 using Microsoft.Extensions.FileProviders.Physical;
 using Microsoft.Extensions.ProjectModel.Internal;
 using NuGet.Frameworks;
+using System.Linq;
 
 namespace Microsoft.Extensions.ProjectModel
 {
@@ -23,13 +24,37 @@ namespace Microsoft.Extensions.ProjectModel
         private IFileInfo _fileInfo;
         private string[] _buildTargets;
         private Dictionary<string, string> _globalProperties = new Dictionary<string, string>();
-        private bool _explicitMsBuild;
+        private MsBuildContext _msbuildContext;
 
         public MsBuildProjectContextBuilder()
         {
             Initialize();
         }
 
+        public virtual MsBuildProjectContextBuilder Clone()
+        {
+            var builder = new MsBuildProjectContextBuilder()
+                .WithProperties(_globalProperties)
+                .WithBuildTargets(_buildTargets);
+
+            if (_msbuildContext != null)
+            {
+                builder.UseMsBuild(_msbuildContext);
+            }
+
+            if (_fileInfo != null)
+            {
+                builder.WithProjectFile(_fileInfo);
+            }
+
+            if (_configuration != null)
+            {
+                builder.WithConfiguration(_configuration);
+            }
+
+            return builder;
+        }
+
         public MsBuildProjectContextBuilder WithBuildTargets(string[] targets)
         {
             if (targets == null)
@@ -60,8 +85,27 @@ namespace Microsoft.Extensions.ProjectModel
         // should be needed in most cases, but can be used to override
         public MsBuildProjectContextBuilder UseMsBuild(MsBuildContext context)
         {
-            _explicitMsBuild = true;
+            _msbuildContext = context;
-            SetMsBuildContext(context);
+
+            /*
+            Workaround https://github.com/Microsoft/msbuild/issues/999
+            Error: System.TypeInitializationException : The type initializer for 'BuildEnvironmentHelperSingleton' threw an exception.
+            Could not determine a valid location to MSBuild. Try running this process from the Developer Command Prompt for Visual Studio.
+            */
+
+            Environment.SetEnvironmentVariable("MSBUILD_EXE_PATH", context.MsBuildExecutableFullPath);
+            WithProperty("MSBuildExtensionsPath", context.ExtensionsPath);
+
+            return this;
+        }
+
+        public MsBuildProjectContextBuilder WithProperties(IDictionary<string, string> properties)
+        {
+            foreach (var prop in properties)
+            {
+                _globalProperties[prop.Key] = prop.Value;
+            }
+
             return this;
         }
 
@@ -84,11 +128,11 @@ namespace Microsoft.Extensions.ProjectModel
 
         public MsBuildProjectContextBuilder WithProjectFile(IFileInfo fileInfo)
         {
-            if (!_explicitMsBuild)
+            if (_msbuildContext == null)
             {
                 var projectDir = Path.GetDirectoryName(fileInfo.PhysicalPath);
                 var sdk = DotNetCoreSdkResolver.DefaultResolver.ResolveProjectSdk(projectDir);
-                SetMsBuildContext(MsBuildContext.FromDotNetSdk(sdk));
+                UseMsBuild(MsBuildContext.FromDotNetSdk(sdk));
             }
 
             _fileInfo = fileInfo;
@@ -105,12 +149,41 @@ namespace Microsoft.Extensions.ProjectModel
         {
             var projectCollection = CreateProjectCollection();
             var project = CreateProject(_fileInfo, _configuration, _globalProperties, projectCollection);
+            if (project.GetProperty("TargetFramework") == null)
+            {
+                var frameworks = GetAvailableTargetFrameworks(project).ToList();
+                if (frameworks.Count > 1)
+                {
+                    throw new InvalidOperationException($"Multiple frameworks are available. Either use {nameof(WithTargetFramework)} or {nameof(BuildAllTargetFrameworks)}");
+                }
+
+                if (frameworks.Count == 0)
+                {
+                    throw new InvalidOperationException($"No frameworks are available. Either use {nameof(WithTargetFramework)} or {nameof(BuildAllTargetFrameworks)}");
+                }
+
+                project.SetGlobalProperty("TargetFramework", frameworks.Single());
+            }
+
             var projectInstance = CreateProjectInstance(project, _buildTargets, ignoreBuildErrors);
 
             var name = Path.GetFileNameWithoutExtension(_fileInfo.Name);
             return new MsBuildProjectContext(name, _configuration, projectInstance);
         }
 
+        public IEnumerable<MsBuildProjectContext> BuildAllTargetFrameworks()
+        {
+            var projectCollection = CreateProjectCollection();
+            var project = CreateProject(_fileInfo, _configuration, _globalProperties, projectCollection);
+
+            foreach (var framework in GetAvailableTargetFrameworks(project))
+            {
+                var builder = Clone();
+                builder.WithTargetFramework(framework);
+                yield return builder.Build();
+            }
+        }
+
         protected virtual void Initialize()
         {
             WithBuildTargets(new[] { "ResolveReferences" });
@@ -167,22 +240,20 @@ namespace Microsoft.Extensions.ProjectModel
             throw new InvalidOperationException(sb.ToString());
         }
 
-        private void SetMsBuildContext(MsBuildContext context)
+        private IEnumerable<string> GetAvailableTargetFrameworks(Project project)
         {
-            /*
+            var frameworks = project.GetProperty("TargetFrameworks")?.EvaluatedValue;
-            Workaround https://github.com/Microsoft/msbuild/issues/999
+            if (string.IsNullOrEmpty(frameworks))
-            Error: System.TypeInitializationException : The type initializer for 'BuildEnvironmentHelperSingleton' threw an exception.
+            {
-            Could not determine a valid location to MSBuild. Try running this process from the Developer Command Prompt for Visual Studio.
+                return Enumerable.Empty<string>();
-            */
+            }
-
+            return frameworks.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
-            Environment.SetEnvironmentVariable("MSBUILD_EXE_PATH", context.MsBuildExecutableFullPath);
-            WithProperty("MSBuildExtensionsPath", context.ExtensionsPath);
         }
 
         private class InMemoryLogger : ILogger
         {
             private readonly Stack<Action> _onShutdown = new Stack<Action>();
-            
+
             internal IList<BuildErrorEventArgs> Errors = new List<BuildErrorEventArgs>();
 
             public string Parameters { get; set; }

test/Microsoft.Extensions.ProjectModel.Tests/MsBuild/MsBuildProjectContextBuilderTest.cs

@@ -1,6 +1,7 @@
 // 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;
 using System.IO;
 using System.Linq;
 using Microsoft.DotNet.Cli.Utils;
@@ -11,26 +12,59 @@ using Xunit.Abstractions;
 
 namespace Microsoft.Extensions.ProjectModel
 {
-    public class MsBuildProjectContextBuilderTest : IClassFixture<MsBuildFixture>
+    public class MsBuildProjectContextBuilderTest : IClassFixture<MsBuildFixture>, IDisposable
     {
         private const string SkipReason = "CI doesn't yet have a new enough version of .NET Core SDK";
 
         private readonly MsBuildFixture _fixture;
         private readonly ITestOutputHelper _output;
+        private readonly TemporaryFileProvider _files;
 
         public MsBuildProjectContextBuilderTest(MsBuildFixture fixture, ITestOutputHelper output)
         {
             _fixture = fixture;
             _output = output;
+            _files = new TemporaryFileProvider();
+        }
+
+        public void Dispose()
+        {
+            _files.Dispose();
+        }
+
+        [Fact(Skip = SkipReason)]
+        public void BuildsAllTargetFrameworks()
+        {
+
+            _files.Add("test.proj", @"
+<Project ToolsVersion=""14.0"" xmlns=""http://schemas.microsoft.com/developer/msbuild/2003"">
+  <PropertyGroup>
+    <TargetFrameworks>net451;netstandard1.3</TargetFrameworks>
+  </PropertyGroup>
+</Project>
+");
+            var contexts = new MsBuildProjectContextBuilder()
+                .WithBuildTargets(Array.Empty<string>())
+                .WithProjectFile(_files.GetFileInfo("test.proj"))
+                .BuildAllTargetFrameworks()
+                .ToList();
+
+            Assert.Collection(contexts,
+                context =>
+                {
+                    Assert.Equal(FrameworkConstants.CommonFrameworks.Net451, context.TargetFramework);
+                },
+                context =>
+                {
+                    Assert.Equal(FrameworkConstants.CommonFrameworks.NetStandard13, context.TargetFramework);
+                });
         }
 
         [Fact(Skip = SkipReason)]
         public void ExecutesDesignTimeBuild()
         {
-            using (var fileProvider = new TemporaryFileProvider())
+            // TODO remove when SDK becomes available on other feeds
-            {
+            _files.Add("NuGet.config", @"
-                // TODO remove when SDK becomes available on other feeds
-                fileProvider.Add("NuGet.config", @"
 <configuration>
     <packageSources>
         <clear />
@@ -40,7 +74,7 @@ namespace Microsoft.Extensions.ProjectModel
     </packageSources>
 </configuration>");
 
-                fileProvider.Add("test.csproj", @"
+            _files.Add("test.csproj", @"
 <Project ToolsVersion=""14.0"" xmlns=""http://schemas.microsoft.com/developer/msbuild/2003"">
   <Import Project=""$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props"" />
 
@@ -68,39 +102,37 @@ namespace Microsoft.Extensions.ProjectModel
   <Import Project=""$(MSBuildToolsPath)\Microsoft.CSharp.targets"" />
 </Project>
 ");
-                fileProvider.Add("One.cs", "public class Abc {}");
+            _files.Add("One.cs", "public class Abc {}");
-                fileProvider.Add("Two.cs", "public class Abc2 {}");
+            _files.Add("Two.cs", "public class Abc2 {}");
-                fileProvider.Add("Excluded.cs", "public class Abc {}");
+            _files.Add("Excluded.cs", "public class Abc {}");
 
-                var testContext = _fixture.GetMsBuildContext();
+            var testContext = _fixture.GetMsBuildContext();
 
-                var muxer = Path.Combine(testContext.ExtensionsPath, "../..", "dotnet.exe");
+            var muxer = Path.Combine(testContext.ExtensionsPath, "../..", "dotnet.exe");
-                var result = Command
+            var result = Command
-                    .Create(muxer, new[] { "restore3", Path.Combine(fileProvider.Root, "test.csproj") })
+                .Create(muxer, new[] { "restore3", Path.Combine(_files.Root, "test.csproj") })
-                    .OnErrorLine(l => _output.WriteLine(l))
+                .OnErrorLine(l => _output.WriteLine(l))
-                    .OnOutputLine(l => _output.WriteLine(l))
+                .OnOutputLine(l => _output.WriteLine(l))
-                    .Execute();
+                .Execute();
-                Assert.Equal(0, result.ExitCode);
+            Assert.Equal(0, result.ExitCode);
 
-                var expectedCompileItems = new[] { "One.cs", "Two.cs" }.Select(p => Path.Combine(fileProvider.Root, p)).ToArray();
+            var expectedCompileItems = new[] { "One.cs", "Two.cs" }.Select(p => Path.Combine(_files.Root, p)).ToArray();
-                var builder = new MsBuildProjectContextBuilder()
-                    .AsDesignTimeBuild()
-                    .UseMsBuild(testContext)
-                    .WithTargetFramework(FrameworkConstants.CommonFrameworks.NetCoreApp10)
-                    .WithConfiguration("Debug")
-                    .WithProjectFile(fileProvider.GetFileInfo("test.csproj"));
 
-                var context = builder.Build();
+            var context = new MsBuildProjectContextBuilder()
+                .AsDesignTimeBuild()
+                .UseMsBuild(testContext)
+                .WithConfiguration("Debug")
+                .WithProjectFile(_files.GetFileInfo("test.csproj"))
+                .Build();
 
-                Assert.False(fileProvider.GetFileInfo("bin").Exists);
+            Assert.False(_files.GetFileInfo("bin").Exists);
-                Assert.False(fileProvider.GetFileInfo("obj").Exists);
+            Assert.False(_files.GetFileInfo("obj").Exists);
-                Assert.Equal(expectedCompileItems, context.CompilationItems.OrderBy(i => i).ToArray());
+            Assert.Equal(expectedCompileItems, context.CompilationItems.OrderBy(i => i).ToArray());
-                Assert.Equal(Path.Combine(fileProvider.Root, "bin", "Debug", "netcoreapp1.0", "test.dll"), context.AssemblyFullPath);
+            Assert.Equal(Path.Combine(_files.Root, "bin", "Debug", "netcoreapp1.0", "test.dll"), context.AssemblyFullPath);
-                Assert.True(context.IsClassLibrary);
+            Assert.True(context.IsClassLibrary);
-                Assert.Equal("TestProject", context.ProjectName);
+            Assert.Equal("TestProject", context.ProjectName);
-                Assert.Equal(FrameworkConstants.CommonFrameworks.NetCoreApp10, context.TargetFramework);
+            Assert.Equal(FrameworkConstants.CommonFrameworks.NetCoreApp10, context.TargetFramework);
-                Assert.Equal("Microsoft.TestProject", context.RootNamespace);
+            Assert.Equal("Microsoft.TestProject", context.RootNamespace);
-            }
         }
     }
 }