Merge branch 'release/2.2'

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/IntegrationTests/InstrumentationPassIntegrationTest.cs

@@ -52,7 +52,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.IntegrationTests
                 b.AddTargetExtension(new TemplateTargetExtension());
             });
 
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var document = engine.Process(projectItem);

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/InheritsWithViewImports_DesignTime.ir.txt

@@ -10,7 +10,6 @@ Document -
         UsingDirective - (178:6,1 [43] ) - Microsoft.AspNetCore.Mvc.ViewFeatures
         ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_InheritsWithViewImports - MyPageModel<MyModel> - 
             DesignTimeDirective - 
-                DirectiveToken - (10:0,10 [19] InheritsWithViewImports_Imports0.cshtml) - MyPageModel<TModel>
                 DirectiveToken - (231:7,8 [62] ) - global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<TModel>
                 DirectiveToken - (294:7,71 [4] ) - Html
                 DirectiveToken - (308:8,8 [54] ) - global::Microsoft.AspNetCore.Mvc.Rendering.IJsonHelper
@@ -24,6 +23,7 @@ Document -
                 DirectiveToken - (617:12,14 [96] ) - Microsoft.AspNetCore.Mvc.Razor.TagHelpers.UrlResolutionTagHelper, Microsoft.AspNetCore.Mvc.Razor
                 DirectiveToken - (729:13,14 [87] ) - Microsoft.AspNetCore.Mvc.Razor.TagHelpers.HeadTagHelper, Microsoft.AspNetCore.Mvc.Razor
                 DirectiveToken - (832:14,14 [87] ) - Microsoft.AspNetCore.Mvc.Razor.TagHelpers.BodyTagHelper, Microsoft.AspNetCore.Mvc.Razor
+                DirectiveToken - (10:0,10 [19] TestFiles\IntegrationTests\CodeGenerationIntegrationTest\_ViewImports.cshtml) - MyPageModel<TModel>
                 DirectiveToken - (14:1,7 [7] InheritsWithViewImports.cshtml) - MyModel
             CSharpCode - 
                 IntermediateToken -  - CSharp - #pragma warning disable 0414

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/InheritsWithViewImports_Imports0.cshtml

@@ -1 +0,0 @@
-@inherits MyPageModel<TModel>

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/InheritsWithViewImports_Runtime.codegen.cs

@@ -14,7 +14,7 @@ namespace AspNetCore
     using Microsoft.AspNetCore.Mvc.Rendering;
     using Microsoft.AspNetCore.Mvc.ViewFeatures;
     [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"d196fc1c66d46d35e35af9b01c737e12bcce6782", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/InheritsWithViewImports.cshtml")]
-    [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"30a9e14edcefbf4970c45de29d8870cf1a9b90b5", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/InheritsWithViewImports_Imports0.cshtml")]
+    [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"f311ecbb5c4d63980a59c24af5ffe8baa1c3f99a", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/_ViewImports.cshtml")]
     public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_InheritsWithViewImports : MyPageModel<MyModel>
     {
         #pragma warning disable 1998

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X.Test/IntegrationTests/CodeGenerationIntegrationTest.cs

@@ -1,55 +1,78 @@
 // 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.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Reflection;
-using System.Text.RegularExpressions;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.Language.IntegrationTests;
 using Microsoft.AspNetCore.Razor.TagHelpers;
-using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
-using Microsoft.CodeAnalysis.Emit;
-using Microsoft.CodeAnalysis.Razor;
-using Microsoft.Extensions.DependencyModel;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X.IntegrationTests
 {
     public class CodeGenerationIntegrationTest : IntegrationTestBase
     {
-        private static readonly RazorSourceDocument DefaultImports = MvcRazorTemplateEngine.GetDefaultImports();
+        private readonly static CSharpCompilation DefaultBaseCompilation = MvcShim.BaseCompilation.WithAssemblyName("AppCode");
 
-        private CSharpCompilation BaseCompilation => MvcShim.BaseCompilation.WithAssemblyName("AppCode");
+        public CodeGenerationIntegrationTest()
+            : base(generateBaselines: null)
+        {
+            Configuration = RazorConfiguration.Create(
+                RazorLanguageVersion.Version_1_1,
+                "MVC-1.1",
+                new[] { new AssemblyExtension("MVC-1.1", typeof(ExtensionInitializer).Assembly) });
+        }
+
+        protected override CSharpCompilation BaseCompilation => DefaultBaseCompilation;
+
+        protected override RazorConfiguration Configuration { get; }
 
         [Fact]
         public void InvalidNamespaceAtEOF_DesignTime()
         {
-            var compilation = BaseCompilation;
+            // Arrange
-            RunDesignTimeTest(compilation);
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToCSharp(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
+
+            var diagnotics = compiled.CodeDocument.GetCSharpDocument().Diagnostics;
+            Assert.Equal("RZ1007", Assert.Single(diagnotics).Id);
         }
 
         [Fact]
         public void IncompleteDirectives_DesignTime()
         {
-            var appCode = @"
+            // Arrange
+            AddCSharpSyntaxTree(@"
 public class MyService<TModel>
 {
     public string Html { get; set; }
-}
+}");
-";
 
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+            var projectItem = CreateProjectItemFromFile();
-            RunDesignTimeTest(compilation);
+
+            // Act
+            var compiled = CompileToCSharp(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
+
+            // We expect this test to generate a bunch of errors.
+            Assert.True(compiled.CodeDocument.GetCSharpDocument().Diagnostics.Count > 0);
         }
 
         [Fact]
         public void InheritsViewModel_DesignTime()
         {
-            var appCode = @"
+            // Arrange
+            AddCSharpSyntaxTree(@"
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.Razor;
 
@@ -60,20 +83,28 @@ public class MyBasePageForViews<TModel> : RazorPage
         throw new System.NotImplementedException();
     }
 }
-
 public class MyModel
 {
 
 }
-";
+");
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+
-            RunDesignTimeTest(compilation);
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void InheritsWithViewImports_DesignTime()
         {
-            var appCode = @"
+            // Arrange
+            AddCSharpSyntaxTree(@"
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc.Razor;
 
@@ -88,61 +119,102 @@ public class MyBasePageForViews<TModel> : RazorPage
 public class MyModel
 {
 
-}
+}");
-";
 
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+            AddProjectItemFromText(@"@inherits MyBasePageForViews<TModel>");
-            RunDesignTimeTest(compilation);
+
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void Basic_DesignTime()
         {
-            var compilation = BaseCompilation;
+            // Arrange
-            RunDesignTimeTest(compilation);
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void Sections_DesignTime()
         {
-            var appCode = $@"
+            // Arrange
+            AddCSharpSyntaxTree($@"
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
 
 public class InputTestTagHelper : {typeof(TagHelper).FullName}
 {{
     public ModelExpression For {{ get; set; }}
 }}
-";
+");
 
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+            var projectItem = CreateProjectItemFromFile();
 
-            RunDesignTimeTest(compilation);
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void _ViewImports_DesignTime()
         {
-            var compilation = BaseCompilation;
+            // Arrange
-            RunDesignTimeTest(compilation);
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void Inject_DesignTime()
         {
-            var appCode = @"
+            // Arrange
+            AddCSharpSyntaxTree(@"
 public class MyApp
 {
     public string MyProperty { get; set; }
 }
-";
+");
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+
-            RunDesignTimeTest(compilation);
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void InjectWithModel_DesignTime()
         {
-            var appCode = @"
+            // Arrange
+            AddCSharpSyntaxTree(@"
 public class MyModel
 {
 
@@ -156,75 +228,119 @@ public class MyService<TModel>
 public class MyApp
 {
     public string MyProperty { get; set; }
-}
+}");
-";
+
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+            var projectItem = CreateProjectItemFromFile();
-            RunDesignTimeTest(compilation);
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void InjectWithSemicolon_DesignTime()
         {
-            var appCode = @"
+            // Arrange
+            AddCSharpSyntaxTree(@"
 public class MyModel
 {
 
 }
 
-public class MyService<TModel>
-{
-    public string Html { get; set; }
-}
-
 public class MyApp
 {
     public string MyProperty { get; set; }
 }
-";
+
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+public class MyService<TModel>
-            RunDesignTimeTest(compilation);
+{
+    public string Html { get; set; }
+}
+");
+
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void Model_DesignTime()
         {
-            var compilation = BaseCompilation;
+            // Arrange
-            RunDesignTimeTest(compilation);
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void MultipleModels_DesignTime()
         {
-            var appCode = @"
+            // Arrange
+            AddCSharpSyntaxTree(@"
 public class ThisShouldBeGenerated
 {
 
-}";
+}");
 
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+            var projectItem = CreateProjectItemFromFile();
-            RunDesignTimeTest(compilation);
+
+            // Act
+            var compiled = CompileToCSharp(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
+
+            var diagnotics = compiled.CodeDocument.GetCSharpDocument().Diagnostics;
+            Assert.Equal("RZ2001", Assert.Single(diagnotics).Id);
         }
         
         [Fact]
         public void ModelExpressionTagHelper_DesignTime()
         {
-            var appCode = $@"
+            // Arrange
+            AddCSharpSyntaxTree($@"
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
 
 public class InputTestTagHelper : {typeof(TagHelper).FullName}
 {{
     public ModelExpression For {{ get; set; }}
 }}
-";
+");
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
 
-            RunDesignTimeTest(compilation);
+            var projectItem = CreateProjectItemFromFile();
+
+            // Act
+            var compiled = CompileToAssembly(projectItem, designTime: true);
+
+            // Assert
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
         }
 
         [Fact]
         public void ViewComponentTagHelper_DesignTime()
         {
-            var appCode = $@"
+            // Arrange
+            AddCSharpSyntaxTree($@"
 public class TestViewComponent
 {{
     public string Invoke(string firstName)
@@ -238,126 +354,17 @@ public class AllTagHelper : {typeof(TagHelper).FullName}
 {{
     public string Bar {{ get; set; }}
 }}
-";
+");
 
-            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(appCode));
+            var projectItem = CreateProjectItemFromFile();
-
-            RunDesignTimeTest(compilation);
-        }
-
-        private void RunDesignTimeTest(
-            CSharpCompilation baseCompilation,
-            IEnumerable<string> expectedErrors = null)
-        {
-            Assert.Empty(baseCompilation.GetDiagnostics());
-            
-            // Arrange
-            var engine = CreateEngine(baseCompilation);
-            var projectItem = CreateProjectItem();
 
             // Act
-            var document = engine.ProcessDesignTime(projectItem);
+            var compiled = CompileToAssembly(projectItem, designTime: true);
 
             // Assert
-            AssertDocumentNodeMatchesBaseline(document.GetDocumentIntermediateNode());
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
-            AssertCSharpDocumentMatchesBaseline(document.GetCSharpDocument());
+            AssertCSharpDocumentMatchesBaseline(compiled.CodeDocument.GetCSharpDocument());
-            AssertSourceMappingsMatchBaseline(document);
+            AssertSourceMappingsMatchBaseline(compiled.CodeDocument);
-            AssertDocumentCompiles(document, baseCompilation, expectedErrors);
-        }
-
-        private void AssertDocumentCompiles(
-            RazorCodeDocument document,
-            CSharpCompilation baseCompilation,
-            IEnumerable<string> expectedErrors = null)
-        {
-            var cSharp = document.GetCSharpDocument().GeneratedCode;
-
-            var syntaxTree = CSharpSyntaxTree.ParseText(cSharp);
-            var options = new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary);
-
-            var references = baseCompilation.References.Concat(new[] { baseCompilation.ToMetadataReference() });
-            var compilation = CSharpCompilation.Create("CodeGenerationTestAssembly", new[] { syntaxTree }, references, options);
-
-            var diagnostics = compilation.GetDiagnostics();
-
-            var errors = diagnostics.Where(d => d.Severity >= DiagnosticSeverity.Warning);
-
-            if (expectedErrors == null)
-            {
-                Assert.Empty(errors.Select(e => e.GetMessage()));
-            }
-            else
-            {
-                Assert.Equal(expectedErrors, errors.Select(e => e.GetMessage()));
-            }
-        }
-
-        protected RazorProjectEngine CreateEngine(CSharpCompilation compilation)
-        {
-            var references = compilation.References.Concat(new[] { compilation.ToMetadataReference() });
-
-            return CreateProjectEngine(b =>
-            {
-                RazorExtensions.Register(b);
-                RazorExtensions.RegisterViewComponentTagHelpers(b);
-
-                var existingImportFeature = b.Features.OfType<IImportProjectFeature>().Single();
-                b.SetImportFeature(new NormalizedDefaultImportFeature(existingImportFeature));
-
-                b.Features.Add(GetMetadataReferenceFeature(references));
-                b.Features.Add(new CompilationTagHelperFeature());
-            });
-        }
-
-        private static IRazorEngineFeature GetMetadataReferenceFeature(IEnumerable<MetadataReference> references)
-        {
-            return new DefaultMetadataReferenceFeature()
-            {
-                References = references.ToList()
-            };
-        }
-
-        private class NormalizedDefaultImportFeature : RazorProjectEngineFeatureBase, IImportProjectFeature
-        {
-            private IImportProjectFeature _existingFeature;
-
-            public NormalizedDefaultImportFeature(IImportProjectFeature existingFeature)
-            {
-                _existingFeature = existingFeature;
-            }
-
-            protected override void OnInitialized()
-            {
-                _existingFeature.ProjectEngine = ProjectEngine;
-            }
-
-            public IReadOnlyList<RazorProjectItem> GetImports(RazorProjectItem projectItem)
-            {
-                var normalizedImports = new List<RazorProjectItem>();
-                var imports = _existingFeature.GetImports(projectItem);
-                foreach (var import in imports)
-                {
-                    var text = string.Empty;
-                    using (var stream = import.Read())
-                    using (var reader = new StreamReader(stream))
-                    {
-                        text = reader.ReadToEnd().Trim();
-                    }
-
-                    // It's important that we normalize the newlines in the default imports. The default imports will
-                    // be created with Environment.NewLine, but we need to normalize to `\r\n` so that the indices
-                    // are the same on xplat.
-                    var normalizedText = Regex.Replace(text, "(?<!\r)\n", "\r\n", RegexOptions.None, TimeSpan.FromSeconds(10));
-                    var normalizedImport = new TestRazorProjectItem(import.FilePath, import.PhysicalPath, import.RelativePhysicalPath, import.BasePath)
-                    {
-                        Content = normalizedText
-                    };
-
-                    normalizedImports.Add(normalizedImport);
-                }
-
-                return normalizedImports;
-            }
         }
     }
 }

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/InheritsWithViewImports_DesignTime.ir.txt

@@ -10,7 +10,6 @@ Document -
         UsingDirective - (178:6,1 [43] ) - Microsoft.AspNetCore.Mvc.ViewFeatures
         ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_InheritsWithViewImports - MyBasePageForViews<MyModel> - 
             DesignTimeDirective - 
-                DirectiveToken - (10:0,10 [26] InheritsWithViewImports_Imports0.cshtml) - MyBasePageForViews<TModel>
                 DirectiveToken - (231:7,8 [62] ) - global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<TModel>
                 DirectiveToken - (294:7,71 [4] ) - Html
                 DirectiveToken - (308:8,8 [54] ) - global::Microsoft.AspNetCore.Mvc.Rendering.IJsonHelper
@@ -22,6 +21,7 @@ Document -
                 DirectiveToken - (507:11,8 [70] ) - global::Microsoft.AspNetCore.Mvc.ViewFeatures.IModelExpressionProvider
                 DirectiveToken - (578:11,79 [23] ) - ModelExpressionProvider
                 DirectiveToken - (617:12,14 [96] ) - Microsoft.AspNetCore.Mvc.Razor.TagHelpers.UrlResolutionTagHelper, Microsoft.AspNetCore.Mvc.Razor
+                DirectiveToken - (10:0,10 [26] TestFiles\IntegrationTests\CodeGenerationIntegrationTest\_ViewImports.cshtml) - MyBasePageForViews<TModel>
                 DirectiveToken - (7:0,7 [7] InheritsWithViewImports.cshtml) - MyModel
             CSharpCode - 
                 IntermediateToken -  - CSharp - #pragma warning disable 0414

test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/InheritsWithViewImports_Imports0.cshtml

@@ -1 +0,0 @@
-@inherits MyBasePageForViews<TModel>

test/Microsoft.AspNetCore.Razor.Language.Test/IntegrationTests/BasicIntegrationTest.cs

@@ -13,7 +13,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
         {
             // Arrange
             var projectEngine = CreateProjectEngine();
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);
@@ -27,7 +27,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
         {
             // Arrange
             var projectEngine = CreateProjectEngine();
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);
@@ -45,7 +45,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
                 b.AddDirective(DirectiveDescriptor.CreateDirective("test", DirectiveKind.SingleLine));
             });
 
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);
@@ -53,65 +53,5 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
             // Assert
             AssertDocumentNodeMatchesBaseline(codeDocument.GetDocumentIntermediateNode());
         }
-
-        [Fact]
-        public void BuildEngine_CallProcess()
-        {
-            // Arrange
-            var projectEngine = CreateProjectEngine();
-            var projectItem = new TestRazorProjectItem("Index.cshtml");
-
-            // Act
-            var codeDocument = projectEngine.Process(projectItem);
-
-            // Assert
-            Assert.NotNull(codeDocument.GetSyntaxTree());
-            Assert.NotNull(codeDocument.GetDocumentIntermediateNode());
-        }
-
-        [Fact]
-        public void CSharpDocument_Runtime_PreservesParserErrors()
-        {
-            // Arrange
-            var projectEngine = CreateProjectEngine();
-            var projectItem = new TestRazorProjectItem("test.cshtml")
-            {
-                Content = "@!!!"
-            };
-
-            var expected = RazorDiagnosticFactory.CreateParsing_UnexpectedCharacterAtStartOfCodeBlock(
-                                new SourceSpan(new SourceLocation("test.cshtml", 1, 0, 1), contentLength: 1),
-                                "!");
-
-            // Act
-            var codeDocument = projectEngine.Process(projectItem);
-
-            // Assert
-            var csharpDocument = codeDocument.GetCSharpDocument();
-            var error = Assert.Single(csharpDocument.Diagnostics);
-            Assert.Equal(expected, error);
-        }
-
-        [Fact]
-        public void CSharpDocument_DesignTime_PreservesParserErrors()
-        {
-            // Arrange
-            var projectEngine = CreateProjectEngine();
-            var projectItem = new TestRazorProjectItem("test.cshtml")
-            {
-                Content = "@{"
-            };
-
-            var expected = RazorDiagnosticFactory.CreateParsing_ExpectedEndOfBlockBeforeEOF(
-                new SourceSpan(new SourceLocation("test.cshtml", 1, 0, 1), contentLength: 1), Resources.BlockName_Code, "}", "{");
-
-            // Act
-            var codeDocument = projectEngine.ProcessDesignTime(projectItem);
-
-            // Assert
-            var csharpDocument = codeDocument.GetCSharpDocument();
-            var error = Assert.Single(csharpDocument.Diagnostics);
-            Assert.Equal(expected, error);
-        }
     }
 }

test/Microsoft.AspNetCore.Razor.Language.Test/IntegrationTests/CodeGenerationIntegrationTest.cs

@@ -10,6 +10,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
 {
     public class CodeGenerationIntegrationTest : IntegrationTestBase
     {
+
         #region Runtime
         [Fact]
         public void IncompleteDirectives_Runtime()
@@ -23,12 +24,6 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
             RunTimeTest();
         }
 
-        [Fact]
-        public void BasicImports_Runtime()
-        {
-            RunTimeTest();
-        }
-
         [Fact]
         public void UnfinishedExpressionInCode_Runtime()
         {
@@ -460,12 +455,6 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
             DesignTimeTest();
         }
 
-        [Fact]
-        public void BasicImports_DesignTime()
-        {
-            DesignTimeTest();
-        }
-
         [Fact]
         public void UnfinishedExpressionInCode_DesignTime()
         {
@@ -896,7 +885,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
                 SectionDirective.Register(builder);
             });
 
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.ProcessDesignTime(projectItem);
@@ -922,7 +911,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
                 SectionDirective.Register(builder);
             });
 
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);
@@ -947,7 +936,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
                 SectionDirective.Register(builder);
             });
 
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
             var imports = GetImports(projectEngine, projectItem);
 
             // Act
@@ -973,7 +962,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
                 SectionDirective.Register(builder);
             });
 
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
             var imports = GetImports(projectEngine, projectItem);
 
             // Act

test/Microsoft.AspNetCore.Razor.Language.Test/IntegrationTests/ExtensibleDirectiveTest.cs

@@ -19,7 +19,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
                 builder.AddDirective(DirectiveDescriptor.CreateDirective("custom", DirectiveKind.SingleLine, b => b.AddNamespaceToken()));
             });
 
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = engine.ProcessDesignTime(projectItem);

test/Microsoft.AspNetCore.Razor.Language.Test/IntegrationTests/HtmlAttributeIntegrationTest.cs

@@ -11,28 +11,26 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
         public void HtmlWithDataDashAttribute()
         {
             // Arrange
-            var projectEngine = CreateProjectEngine();
+            var projectItem = CreateProjectItemFromFile();
-            var projectItem = CreateProjectItem();
 
             // Act
-            var codeDocument = projectEngine.Process(projectItem);
+            var compiled = CompileToCSharp(projectItem);
 
             // Assert
-            AssertDocumentNodeMatchesBaseline(codeDocument.GetDocumentIntermediateNode());
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
         }
 
         [Fact]
         public void HtmlWithConditionalAttribute()
         {
             // Arrange
-            var projectEngine = CreateProjectEngine();
+            var projectItem = CreateProjectItemFromFile();
-            var projectItem = CreateProjectItem();
 
             // Act
-            var codeDocument = projectEngine.Process(projectItem);
+            var compiled = CompileToCSharp(projectItem);
 
             // Assert
-            AssertDocumentNodeMatchesBaseline(codeDocument.GetDocumentIntermediateNode());
+            AssertDocumentNodeMatchesBaseline(compiled.CodeDocument.GetDocumentIntermediateNode());
         }
     }
 }

test/Microsoft.AspNetCore.Razor.Language.Test/IntegrationTests/TagHelpersIntegrationTest.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
             };
 
             var projectEngine = CreateProjectEngine(builder => builder.AddTagHelpers(descriptors));
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);
@@ -51,7 +51,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
             };
 
             var projectEngine = CreateProjectEngine(builder => builder.AddTagHelpers(descriptors));
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);
@@ -88,7 +88,7 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
             };
 
             var projectEngine = CreateProjectEngine(builder => builder.AddTagHelpers(descriptors));
-            var projectItem = CreateProjectItem();
+            var projectItem = CreateProjectItemFromFile();
 
             // Act
             var codeDocument = projectEngine.Process(projectItem);

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports.cshtml

@@ -1 +0,0 @@
-<p>Hi there!</p>

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_DesignTime.codegen.cs

@@ -1,37 +0,0 @@
-// <auto-generated/>
-#pragma warning disable 1591
-namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
-{
-    #line hidden
-#line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
-using System.Globalization;
-
-#line default
-#line hidden
-#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
-using System.ComponentModel;
-
-#line default
-#line hidden
-#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports1.cshtml"
-using System.Text;
-
-#line default
-#line hidden
-    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_BasicImports_DesignTime : Hello
-    {
-        #pragma warning disable 219
-        private void __RazorDirectiveTokenHelpers__() {
-        }
-        #pragma warning restore 219
-        #pragma warning disable 0414
-        private static System.Object __o = null;
-        #pragma warning restore 0414
-        #pragma warning disable 1998
-        public async System.Threading.Tasks.Task ExecuteAsync()
-        {
-        }
-        #pragma warning restore 1998
-    }
-}
-#pragma warning restore 1591

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_DesignTime.ir.txt

@@ -1,20 +0,0 @@
-Document - 
-    NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
-        UsingDirective - (1:0,1 [26] BasicImports_Imports0.cshtml) - System.Globalization
-        UsingDirective - (30:1,1 [27] BasicImports_Imports0.cshtml) - System.ComponentModel
-        UsingDirective - (23:1,1 [18] BasicImports_Imports1.cshtml) - System.Text
-        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_BasicImports_DesignTime - Hello - 
-            DesignTimeDirective - 
-                DirectiveToken - (69:2,10 [5] BasicImports_Imports0.cshtml) - Hello
-            CSharpCode - 
-                IntermediateToken -  - CSharp - #pragma warning disable 0414
-            CSharpCode - 
-                IntermediateToken -  - CSharp - private static System.Object __o = null;
-            CSharpCode - 
-                IntermediateToken -  - CSharp - #pragma warning restore 0414
-            MethodDeclaration -  - public async - System.Threading.Tasks.Task - ExecuteAsync
-                HtmlContent - (0:0,0 [18] BasicImports.cshtml)
-                    IntermediateToken - (0:0,0 [3] BasicImports.cshtml) - Html - <p>
-                    IntermediateToken - (3:0,3 [9] BasicImports.cshtml) - Html - Hi there!
-                    IntermediateToken - (12:0,12 [4] BasicImports.cshtml) - Html - </p>
-                    IntermediateToken - (16:0,16 [2] BasicImports.cshtml) - Html - \n

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml

@@ -1,5 +0,0 @@
-@using System.Globalization
-@using System.ComponentModel
-@inherits Hello
-@("And also this")
-<p>This will get ignored</p>

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports1.cshtml

@@ -1,2 +0,0 @@
-@section ignored { }
-@using System.Text;

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Runtime.codegen.cs

@@ -1,36 +0,0 @@
-#pragma checksum "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "d5e5d28c0c504a7b0c5207a5230a5b7327ce5e09"
-// <auto-generated/>
-#pragma warning disable 1591
-[assembly: global::Microsoft.AspNetCore.Razor.Hosting.RazorCompiledItemAttribute(typeof(Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_BasicImports_Runtime), @"default", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports.cshtml")]
-namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
-{
-    #line hidden
-#line 1 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
-using System.Globalization;
-
-#line default
-#line hidden
-#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml"
-using System.ComponentModel;
-
-#line default
-#line hidden
-#line 2 "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports1.cshtml"
-using System.Text;
-
-#line default
-#line hidden
-    [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"d5e5d28c0c504a7b0c5207a5230a5b7327ce5e09", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports.cshtml")]
-    [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"39c22940acc420eb6d46b6ff85ef6d5a2ab35fa1", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports0.cshtml")]
-    [global::Microsoft.AspNetCore.Razor.Hosting.RazorSourceChecksumAttribute(@"SHA1", @"ede697b6fb90aac312d589ae96a93289cdeb506f", @"/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Imports1.cshtml")]
-    public class TestFiles_IntegrationTests_CodeGenerationIntegrationTest_BasicImports_Runtime : Hello
-    {
-        #pragma warning disable 1998
-        public async System.Threading.Tasks.Task ExecuteAsync()
-        {
-            WriteLiteral("<p>Hi there!</p>\r\n");
-        }
-        #pragma warning restore 1998
-    }
-}
-#pragma warning restore 1591

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicImports_Runtime.ir.txt

@@ -1,16 +0,0 @@
-Document - 
-    RazorCompiledItemAttribute - 
-    NamespaceDeclaration -  - Microsoft.AspNetCore.Razor.Language.IntegrationTests.TestFiles
-        UsingDirective - (1:0,1 [28] BasicImports_Imports0.cshtml) - System.Globalization
-        UsingDirective - (30:1,1 [29] BasicImports_Imports0.cshtml) - System.ComponentModel
-        UsingDirective - (23:1,1 [20] BasicImports_Imports1.cshtml) - System.Text
-        RazorSourceChecksumAttribute - 
-        RazorSourceChecksumAttribute - 
-        RazorSourceChecksumAttribute - 
-        ClassDeclaration -  - public - TestFiles_IntegrationTests_CodeGenerationIntegrationTest_BasicImports_Runtime - Hello - 
-            MethodDeclaration -  - public async - System.Threading.Tasks.Task - ExecuteAsync
-                HtmlContent - (0:0,0 [18] BasicImports.cshtml)
-                    IntermediateToken - (0:0,0 [3] BasicImports.cshtml) - Html - <p>
-                    IntermediateToken - (3:0,3 [9] BasicImports.cshtml) - Html - Hi there!
-                    IntermediateToken - (12:0,12 [4] BasicImports.cshtml) - Html - </p>
-                    IntermediateToken - (16:0,16 [2] BasicImports.cshtml) - Html - \n

test/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/CompilationFailedException.cs

@@ -0,0 +1,58 @@
+// 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.Collections.Generic;
+using System.Linq;
+using System.Text;
+using Microsoft.CodeAnalysis;
+using Xunit.Sdk;
+
+namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
+{
+    public class CompilationFailedException : XunitException
+    {
+        public CompilationFailedException(Compilation compilation, Diagnostic[] diagnostics)
+        {
+            Compilation = compilation;
+            Diagnostics = diagnostics;
+        }
+
+        public Compilation Compilation { get; }
+
+        public Diagnostic[] Diagnostics { get; }
+
+        public override string Message
+        {
+            get
+            {
+                var builder = new StringBuilder();
+                builder.AppendLine("Compilation failed: ");
+
+                var syntaxTreesWithErrors = new HashSet<SyntaxTree>();
+                foreach (var diagnostic in Diagnostics)
+                {
+                    builder.AppendLine(diagnostic.ToString());
+
+                    if (diagnostic.Location.IsInSource)
+                    {
+                        syntaxTreesWithErrors.Add(diagnostic.Location.SourceTree);
+                    }
+                }
+
+                if (syntaxTreesWithErrors.Any())
+                {
+                    builder.AppendLine();
+                    builder.AppendLine();
+
+                    foreach (var syntaxTree in syntaxTreesWithErrors)
+                    {
+                        builder.AppendLine($"File {syntaxTree.FilePath ?? "unknown"}:");
+                        builder.AppendLine(syntaxTree.GetText().ToString());
+                    }
+                }
+
+                return builder.ToString();
+            }
+        }
+    }
+}

test/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/CompiledAssembly.cs

@@ -0,0 +1,24 @@
+// 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.Reflection;
+using Microsoft.CodeAnalysis;
+
+namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
+{
+    public class CompiledAssembly
+    {
+        public CompiledAssembly(Compilation compilation, RazorCodeDocument codeDocument, Assembly assembly)
+        {
+            Compilation = compilation;
+            CodeDocument = codeDocument;
+            Assembly = assembly;
+        }
+
+        public Assembly Assembly { get; }
+
+        public RazorCodeDocument CodeDocument { get; }
+
+        public Compilation Compilation { get; }
+    }
+}

test/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/CompiledCSharpCode.cs

@@ -0,0 +1,21 @@
+// 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 Microsoft.CodeAnalysis;
+
+namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
+{
+    public class CompiledCSharpCode
+    {
+        public CompiledCSharpCode(Compilation baseCompilation, RazorCodeDocument codeDocument)
+        {
+            BaseCompilation = baseCompilation;
+            CodeDocument = codeDocument;
+        }
+
+        // A compilation that can be used *with* this code to compile an assembly
+        public Compilation BaseCompilation { get; set; }
+
+        public RazorCodeDocument CodeDocument { get; set; }
+    }
+}

test/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/IntegrationTestBase.cs

@@ -13,11 +13,14 @@ using System.Runtime.Remoting.Messaging;
 #else
 using System.Threading;
 #endif
+using Microsoft.AspNetCore.Razor.Language.Legacy;
 using Microsoft.AspNetCore.Razor.Language.CodeGeneration;
 using Microsoft.AspNetCore.Razor.Language.Intermediate;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Razor;
 using Xunit;
 using Xunit.Sdk;
-using Microsoft.AspNetCore.Razor.Language.Legacy;
 
 namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
 {
@@ -28,15 +31,81 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
         private static readonly AsyncLocal<string> _fileName = new AsyncLocal<string>();
 #endif
 
-        protected IntegrationTestBase()
+        private static readonly CSharpCompilation DefaultBaseCompilation;
+
+        static IntegrationTestBase()
         {
-            TestProjectRoot = TestProject.GetProjectDirectory(GetType());
+            var referenceAssemblyRoots = new[]
+            {
+                typeof(System.Runtime.AssemblyTargetedPatchBandAttribute).Assembly, // System.Runtime
+            };
+
+            var referenceAssemblies = referenceAssemblyRoots
+                .SelectMany(assembly => assembly.GetReferencedAssemblies().Concat(new[] { assembly.GetName() }))
+                .Distinct()
+                .Select(Assembly.Load)
+                .Select(assembly => MetadataReference.CreateFromFile(assembly.Location))
+                .ToList();
+            DefaultBaseCompilation = CSharpCompilation.Create(
+                "TestAssembly",
+                Array.Empty<SyntaxTree>(),
+                referenceAssemblies,
+                new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary));
         }
 
+        protected IntegrationTestBase(bool? generateBaselines = null)
+        {
+            TestProjectRoot = TestProject.GetProjectDirectory(GetType());
+
+            if (generateBaselines.HasValue)
+            {
+                GenerateBaselines = generateBaselines.Value;
+            }
+        }
+
+        /// <summary>
+        /// Gets the <see cref="CSharpCompilation"/> that will be used as the 'app' compilation.
+        /// </summary>
+        protected virtual CSharpCompilation BaseCompilation => DefaultBaseCompilation;
+
+        /// <summary>
+        /// Gets the parse options applied when using <see cref="AddCSharpSyntaxTree(string, string)"/>.
+        /// </summary>
+        protected virtual CSharpParseOptions CSharpParseOptions { get; } = new CSharpParseOptions(LanguageVersion.Latest);
+
+        /// <summary>
+        /// Gets the compilation options applied when compiling assemblies.
+        /// </summary>
+        protected virtual CSharpCompilationOptions CSharpCompilationOptions { get; } = new CSharpCompilationOptions(OutputKind.DynamicallyLinkedLibrary);
+
+        /// <summary>
+        /// Gets a list of CSharp syntax trees used that are considered part of the 'app'.
+        /// </summary>
+        protected virtual List<CSharpSyntaxTree> CSharpSyntaxTrees { get; } = new List<CSharpSyntaxTree>();
+
+        /// <summary>
+        /// Gets the <see cref="RazorConfiguration"/> that will be used for code generation.
+        /// </summary>
+        protected virtual RazorConfiguration Configuration { get; } = RazorConfiguration.Default;
+
+        protected virtual bool DesignTime { get; } = false;
+
+        /// <summary>
+        /// Gets the 
+        /// </summary>
+        internal VirtualRazorProjectFileSystem FileSystem { get; } = new VirtualRazorProjectFileSystem();
+
+        /// <summary>
+        /// Used to force a specific style of line-endings for testing. This matters for the baseline tests that exercise line mappings. 
+        /// Even though we normalize newlines for testing, the difference between platforms affects the data through the *count* of 
+        /// characters written.
+        /// </summary>
+        protected virtual string LineEnding { get; } = "\r\n";
+
 #if GENERATE_BASELINES
-        protected bool GenerateBaselines { get; set; } = true;
+        protected bool GenerateBaselines { get; } = true;
 #else
-        protected bool GenerateBaselines { get; set; } = false;
+        protected bool GenerateBaselines { get; } = false;
 #endif
 
         protected string TestProjectRoot { get; }
@@ -60,34 +129,62 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
 #endif
         }
 
-        protected virtual RazorProjectEngine CreateProjectEngine() => CreateProjectEngine(configure: null);
+        protected virtual void ConfigureProjectEngine(RazorProjectEngineBuilder builder)
-
-        protected virtual RazorProjectEngine CreateProjectEngine(Action<RazorProjectEngineBuilder> configure)
         {
-            if (FileName == null)
-            {
-                var message = $"{nameof(CreateProjectEngine)} should only be called from an integration test, ({nameof(FileName)} is null).";
-                throw new InvalidOperationException(message);
-            }
-
-            var assembly = GetType().GetTypeInfo().Assembly;
-            var projectEngine = RazorProjectEngine.Create(RazorConfiguration.Default, IntegrationTestFileSystem.Default, b =>
-            {
-                configure?.Invoke(b);
-
-                var existingImportFeature = b.Features.OfType<IImportProjectFeature>().Single();
-                b.SetImportFeature(new IntegrationTestImportFeature(assembly, existingImportFeature));
-            });
-            var testProjectEngine = new IntegrationTestProjectEngine(projectEngine);
-
-            return testProjectEngine;
         }
 
-        protected virtual RazorProjectItem CreateProjectItem()
+        protected CSharpSyntaxTree AddCSharpSyntaxTree(string text, string filePath = null)
+        {
+            var syntaxTree = (CSharpSyntaxTree)CSharpSyntaxTree.ParseText(text, CSharpParseOptions, path: filePath);
+            CSharpSyntaxTrees.Add(syntaxTree);
+            return syntaxTree;
+        }
+
+        protected RazorProjectItem AddProjectItemFromText(string text, string filePath = "_ViewImports.cshtml")
+        {
+            var projectItem = CreateProjectItemFromText(text, filePath);
+            FileSystem.Add(projectItem);
+            return projectItem;
+        }
+
+        private RazorProjectItem CreateProjectItemFromText(string text, string filePath)
+        {
+            // Consider the file path to be relative to the 'FileName' of the test.
+            var workingDirectory = Path.GetDirectoryName(FileName);
+
+            // Since these paths are used in baselines, we normalize them to windows style. We
+            // use "" as the base path by convention to avoid baking in an actual file system
+            // path.
+            var basePath = "";
+            var physicalPath = Path.Combine(workingDirectory, filePath).Replace('/', '\\');
+            var relativePhysicalPath = physicalPath;
+
+            // FilePaths in Razor are **always** are of the form '/a/b/c.cshtml'
+            filePath = physicalPath.Replace('\\', '/');
+            if (!filePath.StartsWith("/"))
+            {
+                filePath = '/' + filePath;
+            }
+
+            text = NormalizeNewLines(text);
+
+            var projectItem = new TestRazorProjectItem(
+                basePath: basePath,
+                filePath: filePath,
+                physicalPath: physicalPath,
+                relativePhysicalPath: relativePhysicalPath)
+            {
+                Content = text,
+            };
+            
+            return projectItem;
+        }
+
+        protected RazorProjectItem CreateProjectItemFromFile(string filePath = null)
         {
             if (FileName == null)
             {
-                var message = $"{nameof(CreateProjectItem)} should only be called from an integration test, ({nameof(FileName)} is null).";
+                var message = $"{nameof(CreateProjectItemFromFile)} should only be called from an integration test, ({nameof(FileName)} is null).";
                 throw new InvalidOperationException(message);
             }
 
@@ -102,12 +199,149 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
             var fileContent = testFile.ReadAllText();
             var normalizedContent = NormalizeNewLines(fileContent);
 
-            var projectItem = new TestRazorProjectItem(sourceFileName)
+            var workingDirectory = Path.GetDirectoryName(FileName);
+            var fullPath = sourceFileName;
+
+            // Normalize to forward-slash - these strings end up in the baselines.
+            fullPath = fullPath.Replace('\\', '/');
+            sourceFileName = sourceFileName.Replace('\\', '/');
+
+            // FilePaths in Razor are **always** are of the form '/a/b/c.cshtml'
+            filePath = filePath ?? sourceFileName;
+            if (!filePath.StartsWith("/"))
             {
-                Content = normalizedContent,
+                filePath = '/' + filePath;
+            }
+
+            var projectItem = new TestRazorProjectItem(
+                basePath: workingDirectory,
+                filePath: filePath,
+                physicalPath: fullPath,
+                relativePhysicalPath: sourceFileName)
+            {
+                Content = fileContent,
+            };
+            
+            return projectItem;
+        }
+
+        protected CompiledCSharpCode CompileToCSharp(string text, string path = "test.cshtml", bool? designTime = null)
+        {
+            var projectItem = CreateProjectItemFromText(text, path);
+            return CompileToCSharp(projectItem, designTime);
+        }
+
+        protected CompiledCSharpCode CompileToCSharp(RazorProjectItem projectItem, bool? designTime = null)
+        {
+            var compilation = CreateCompilation();
+            var references = compilation.References.Concat(new[] { compilation.ToMetadataReference(), }).ToArray();
+
+            var projectEngine = CreateProjectEngine(Configuration, references, ConfigureProjectEngine);
+            var codeDocument = (designTime ?? DesignTime) ? projectEngine.ProcessDesignTime(projectItem) : projectEngine.Process(projectItem);
+
+            return new CompiledCSharpCode(CSharpCompilation.Create(compilation.AssemblyName + ".Views", references: references, options: CSharpCompilationOptions), codeDocument);
+        }
+
+        protected CompiledAssembly CompileToAssembly(string text, string path = "test.cshtml", bool? designTime = null, bool throwOnFailure = true)
+        {
+            var compiled = CompileToCSharp(text, path, designTime);
+            return CompileToAssembly(compiled);
+        }
+
+        protected CompiledAssembly CompileToAssembly(RazorProjectItem projectItem, bool? designTime = null, bool throwOnFailure = true)
+        {
+            var compiled = CompileToCSharp(projectItem, designTime);
+            return CompileToAssembly(compiled, throwOnFailure: throwOnFailure);
+        }
+
+        protected CompiledAssembly CompileToAssembly(CompiledCSharpCode code, bool throwOnFailure = true)
+        {
+            var cSharpDocument = code.CodeDocument.GetCSharpDocument();
+            if (cSharpDocument.Diagnostics.Any())
+            {
+                var diagnosticsLog = string.Join(Environment.NewLine, cSharpDocument.Diagnostics.Select(d => d.ToString()).ToArray());
+                throw new InvalidOperationException($"Aborting compilation to assembly because RazorCompiler returned nonempty diagnostics: {diagnosticsLog}");
+            }
+
+            var syntaxTrees = new[]
+            {
+                (CSharpSyntaxTree)CSharpSyntaxTree.ParseText(cSharpDocument.GeneratedCode, CSharpParseOptions, path: code.CodeDocument.Source.FilePath),
             };
 
-            return projectItem;
+            var compilation = code.BaseCompilation.AddSyntaxTrees(syntaxTrees);
+
+            var diagnostics = compilation
+                .GetDiagnostics()
+                .Where(d => d.Severity >= DiagnosticSeverity.Warning)
+                .ToArray();
+
+            if (diagnostics.Length > 0 && throwOnFailure)
+            {
+                throw new CompilationFailedException(compilation, diagnostics);
+            }
+            else if (diagnostics.Any(d => d.Severity == DiagnosticSeverity.Error))
+            {
+                return new CompiledAssembly(compilation, code.CodeDocument, assembly: null);
+            }
+
+            using (var peStream = new MemoryStream())
+            {
+                var emit = compilation.Emit(peStream);
+                diagnostics = emit
+                    .Diagnostics
+                    .Where(d => d.Severity >= DiagnosticSeverity.Warning)
+                    .ToArray();
+                if (diagnostics.Length > 0 && throwOnFailure)
+                {
+                    throw new CompilationFailedException(compilation, diagnostics);
+                }
+
+                return new CompiledAssembly(compilation, code.CodeDocument, Assembly.Load(peStream.ToArray()));
+            }
+        }
+
+        private CSharpCompilation CreateCompilation()
+        {
+            var compilation = BaseCompilation.AddSyntaxTrees(CSharpSyntaxTrees);
+            var diagnostics = compilation.GetDiagnostics().Where(d => d.Severity >= DiagnosticSeverity.Warning).ToArray();
+            if (diagnostics.Length > 0)
+            {
+                throw new CompilationFailedException(compilation, diagnostics);
+            }
+
+            return compilation;
+        }
+
+        protected RazorProjectEngine CreateProjectEngine(Action<RazorProjectEngineBuilder> configure = null)
+        {
+            var compilation = CreateCompilation();
+            var references = compilation.References.Concat(new[] { compilation.ToMetadataReference(), }).ToArray();
+            return CreateProjectEngine(Configuration, references, configure);
+        }
+
+        private RazorProjectEngine CreateProjectEngine(RazorConfiguration configuration, MetadataReference[] references, Action<RazorProjectEngineBuilder> configure)
+        {
+            return RazorProjectEngine.Create(configuration, FileSystem, b =>
+            {
+                b.Phases.Insert(0, new ConfigureCodeRenderingPhase(LineEnding));
+
+                configure?.Invoke(b);
+
+                // Allow the test to do custom things with tag helpers, but do the default thing most of the time.
+                if (!b.Features.OfType<ITagHelperFeature>().Any())
+                {
+                    b.Features.Add(new CompilationTagHelperFeature());
+                    b.Features.Add(new DefaultMetadataReferenceFeature()
+                    {
+                        References = references,
+                    });
+                }
+
+                // Decorate the import feature so we can normalize line endings.
+                var importFeature = b.Features.OfType<IImportProjectFeature>().FirstOrDefault();
+                b.Features.Add(new NormalizedDefaultImportFeature(importFeature, LineEnding));
+                b.Features.Remove(importFeature);
+            });
         }
 
         protected void AssertDocumentNodeMatchesBaseline(DocumentIntermediateNode document)
@@ -318,96 +552,93 @@ namespace Microsoft.AspNetCore.Razor.Language.IntegrationTests
                 .Replace("\t", "\\t");
         }
 
-        private static string NormalizeNewLines(string content)
+        private string NormalizeNewLines(string content)
         {
-            return Regex.Replace(content, "(?<!\r)\n", "\r\n", RegexOptions.None, TimeSpan.FromSeconds(10));
+            return NormalizeNewLines(content, LineEnding);
         }
 
-        private class IntegrationTestProjectEngine : DefaultRazorProjectEngine
+        private static string NormalizeNewLines(string content, string lineEnding)
         {
-            public IntegrationTestProjectEngine(
+            return Regex.Replace(content, "(?<!\r)\n", lineEnding, RegexOptions.None, TimeSpan.FromSeconds(10));
-                RazorProjectEngine innerEngine)
+        }
-                : base(innerEngine.Configuration, innerEngine.Engine, innerEngine.FileSystem, innerEngine.ProjectFeatures)
+
+        // This is to prevent you from accidentally checking in with GenerateBaselines = true
+        [Fact]
+        public void GenerateBaselinesMustBeFalse()
+        {
+            Assert.False(GenerateBaselines, "GenerateBaselines should be set back to false before you check in!");
+        }
+
+        private class ConfigureCodeRenderingPhase : RazorEnginePhaseBase
+        {
+            public ConfigureCodeRenderingPhase(string lineEnding)
             {
+                LineEnding = lineEnding;
             }
 
-            protected override void ProcessCore(RazorCodeDocument codeDocument)
+            public string LineEnding { get; }
+
+            protected override void ExecuteCore(RazorCodeDocument codeDocument)
             {
-                // This will ensure that we're not putting any randomly generated data in a baseline.
                 codeDocument.Items[CodeRenderingContext.SuppressUniqueIds] = "test";
-
+                codeDocument.Items[CodeRenderingContext.NewLineString] = LineEnding;
-                // This is to make tests work cross platform.
-                codeDocument.Items[CodeRenderingContext.NewLineString] = "\r\n";
-
-                base.ProcessCore(codeDocument);
             }
         }
 
-        private class IntegrationTestImportFeature : RazorProjectEngineFeatureBase, IImportProjectFeature
+        // 'Default' imports won't have normalized line-endings, which is unfriendly for testing.
+        private class NormalizedDefaultImportFeature : RazorProjectEngineFeatureBase, IImportProjectFeature
         {
-            private Assembly _assembly;
+            private readonly IImportProjectFeature _inner;
-            private IImportProjectFeature _existingImportFeature;
+            private readonly string _lineEnding;
 
-            public IntegrationTestImportFeature(Assembly assembly, IImportProjectFeature existingImportFeature)
+            public NormalizedDefaultImportFeature(IImportProjectFeature inner, string lineEnding)
             {
-                _assembly = assembly;
+                _inner = inner;
-                _existingImportFeature = existingImportFeature;
+                _lineEnding = lineEnding;
             }
 
             protected override void OnInitialized()
             {
-                _existingImportFeature.ProjectEngine = ProjectEngine;
+                if (_inner != null)
+                {
+                    _inner.ProjectEngine = ProjectEngine;
+                }
             }
 
             public IReadOnlyList<RazorProjectItem> GetImports(RazorProjectItem projectItem)
             {
-                var imports = new List<RazorProjectItem>();
+                if (_inner == null)
-
-                while (true)
                 {
-                    var importsFileName = Path.ChangeExtension(projectItem.FilePathWithoutExtension + "_Imports" + imports.Count.ToString(), ".cshtml");
+                    return Array.Empty<RazorProjectItem>();
-                    var importsFile = TestFile.Create(importsFileName, _assembly);
-                    if (!importsFile.Exists())
-                    {
-                        break;
-                    }
-
-                    var importContent = importsFile.ReadAllText();
-                    var normalizedContent = NormalizeNewLines(importContent);
-                    var importItem = new TestRazorProjectItem(importsFileName)
-                    {
-                        Content = normalizedContent
-                    };
-                    imports.Add(importItem);
                 }
 
-                imports.AddRange(_existingImportFeature.GetImports(projectItem));
+                var normalizedImports = new List<RazorProjectItem>();
+                var imports = _inner.GetImports(projectItem);
+                foreach (var import in imports)
+                {
+                    if (import.Exists)
+                    {
+                        var text = string.Empty;
+                        using (var stream = import.Read())
+                        using (var reader = new StreamReader(stream))
+                        {
+                            text = reader.ReadToEnd().Trim();
+                        }
 
-                return imports;
+                        // It's important that we normalize the newlines in the default imports. The default imports will
-            }
+                        // be created with Environment.NewLine, but we need to normalize to `\r\n` so that the indices
-        }
+                        // are the same on xplat.
+                        var normalizedText = NormalizeNewLines(text, _lineEnding);
+                        var normalizedImport = new TestRazorProjectItem(import.FilePath, import.PhysicalPath, import.RelativePhysicalPath, import.BasePath)
+                        {
+                            Content = normalizedText
+                        };
 
-        private class IntegrationTestFileSystem : RazorProjectFileSystem
+                        normalizedImports.Add(normalizedImport);
-        {
+                    }
-            public static IntegrationTestFileSystem Default = new IntegrationTestFileSystem();
+                }
 
-            private IntegrationTestFileSystem()
+                return normalizedImports;
-            {
-            }
-
-            public override IEnumerable<RazorProjectItem> EnumerateItems(string basePath)
-            {
-                return Enumerable.Empty<RazorProjectItem>();
-            }
-
-            public override RazorProjectItem GetItem(string path)
-            {
-                return new NotFoundProjectItem(string.Empty, path);
-            }
-
-            public override IEnumerable<RazorProjectItem> FindHierarchicalItems(string basePath, string path, string fileName)
-            {
-                return Enumerable.Empty<RazorProjectItem>();
             }
         }
     }

test/Microsoft.AspNetCore.Razor.Test.Common/Microsoft.AspNetCore.Razor.Test.Common.csproj

@@ -9,6 +9,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\..\src\Microsoft.AspNetCore.Razor.Language\Microsoft.AspNetCore.Razor.Language.csproj" />
+    <ProjectReference Include="..\..\src\Microsoft.CodeAnalysis.Razor\Microsoft.CodeAnalysis.Razor.csproj" />
   </ItemGroup>
 
   <ItemGroup>