[Fixes #961] Disable instrumentation for TagHelper attribute values

src/Microsoft.AspNetCore.Razor.Evolution/DefaultInstrumentationPass.cs

@@ -104,6 +104,16 @@ namespace Microsoft.AspNetCore.Razor.Evolution
 
                 VisitDefault(node);
             }
+
+            public override void VisitAddTagHelperHtmlAttribute(AddTagHelperHtmlAttributeIRNode node)
+            {
+                // We don't want to instrument TagHelper attributes. Do nothing.
+            }
+
+            public override void VisitSetTagHelperProperty(SetTagHelperPropertyIRNode node)
+            {
+                // We don't want to instrument TagHelper attributes. Do nothing.
+            }
         }
     }
 }

test/Microsoft.AspNetCore.Razor.Evolution.Test/DefaultInstrumentationPassTest.cs

@@ -111,6 +111,100 @@ namespace Microsoft.AspNetCore.Razor.Evolution
                 n => CSharpExpression("Hi", n));
         }
 
+        [Fact]
+        public void InstrumentationPass_SkipsCSharpExpression_InsideTagHelperAttribute()
+        {
+            // Arrange
+            var builder = RazorIRBuilder.Document();
+            builder.Push(new TagHelperIRNode()
+            {
+                Source = CreateSource(3)
+            });
+
+            builder.Push(new AddTagHelperHtmlAttributeIRNode());
+
+            builder.Push(new CSharpExpressionIRNode()
+            {
+                Source = CreateSource(5)
+            });
+
+            builder.Add(new CSharpTokenIRNode()
+            {
+                Content = "Hi",
+            });
+
+            var irDocument = (DocumentIRNode)builder.Build();
+
+            var pass = new DefaultInstrumentationPass();
+
+            // Act
+            var result = pass.ExecuteCore(TestRazorCodeDocument.CreateEmpty(), irDocument);
+
+            // Assert
+            Children(
+                irDocument,
+                n =>
+                {
+                    Assert.IsType<TagHelperIRNode>(n);
+                    Children(
+                        n,
+                        c =>
+                        {
+                            Assert.IsType<AddTagHelperHtmlAttributeIRNode>(c);
+                            Children(
+                                c,
+                                s => CSharpExpression("Hi", s));
+                        });
+                });
+        }
+
+        [Fact]
+        public void InstrumentationPass_SkipsCSharpExpression_InsideTagHelperProperty()
+        {
+            // Arrange
+            var builder = RazorIRBuilder.Document();
+            builder.Push(new TagHelperIRNode()
+            {
+                Source = CreateSource(3)
+            });
+
+            builder.Push(new SetTagHelperPropertyIRNode());
+
+            builder.Push(new CSharpExpressionIRNode()
+            {
+                Source = CreateSource(5)
+            });
+
+            builder.Add(new CSharpTokenIRNode()
+            {
+                Content = "Hi",
+            });
+
+            var irDocument = (DocumentIRNode)builder.Build();
+
+            var pass = new DefaultInstrumentationPass();
+
+            // Act
+            var result = pass.ExecuteCore(TestRazorCodeDocument.CreateEmpty(), irDocument);
+
+            // Assert
+            Children(
+                irDocument,
+                n =>
+                {
+                    Assert.IsType<TagHelperIRNode>(n);
+                    Children(
+                        n,
+                        c =>
+                        {
+                            Assert.IsType<SetTagHelperPropertyIRNode>(c);
+                            Children(
+                                c,
+                                s => CSharpExpression("Hi", s));
+                        });
+                });
+        }
+
         [Fact]
         public void InstrumentationPass_InstrumentsExecuteTagHelper_InsideTagHelper()
         {
@@ -172,7 +266,6 @@ namespace Microsoft.AspNetCore.Razor.Evolution
                 });
         }
 
-
         [Fact]
         public void InstrumentationPass_SkipsExecuteTagHelper_MalformedTagHelper()
         {

test/Microsoft.AspNetCore.Razor.Evolution.Test/IntegrationTests/InstrumentationPassIntegrationTest.cs

@@ -36,7 +36,13 @@ namespace Microsoft.AspNetCore.Razor.Evolution.IntegrationTests
                         {
                             Name = "value",
                             PropertyName = "FooProp",
-                            TypeName = "System.String"
+                            TypeName = "System.String"      // Gets preallocated
+                        },
+                        new TagHelperAttributeDescriptor
+                        {
+                            Name = "date",
+                            PropertyName = "BarProp",
+                            TypeName = "System.DateTime"   // Doesn't get preallocated
                         }
                     }
                 }
@@ -55,7 +61,9 @@ namespace Microsoft.AspNetCore.Razor.Evolution.IntegrationTests
 
             // Assert
             AssertIRMatchesBaseline(document.GetIRDocument());
-            AssertCSharpDocumentMatchesBaseline(document.GetCSharpDocument());
+            var csharpDocument = document.GetCSharpDocument();
+            AssertCSharpDocumentMatchesBaseline(csharpDocument);
+            Assert.Empty(csharpDocument.Diagnostics);
         }
     }
 }

test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/InstrumentationPassIntegrationTest/BasicTest.codegen.cs

@@ -1,4 +1,4 @@
-#pragma checksum "TestFiles/IntegrationTests/InstrumentationPassIntegrationTest/BasicTest.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "7e1ceb3e8ebe2125cd44bea5d9f4ac1acf9ec12b"
+#pragma checksum "TestFiles/IntegrationTests/InstrumentationPassIntegrationTest/BasicTest.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "5898df8049fc1522f646a774050e93cbf5cafb84"
 namespace 
 {
     #line hidden
@@ -56,8 +56,14 @@ Write("Hello");
                 __tagHelperExecutionContext.Add(__InputTagHelper);
                 __InputTagHelper.FooProp = (string)__tagHelperAttribute_0.Value;
                 __tagHelperExecutionContext.AddTagHelperAttribute(__tagHelperAttribute_0);
+#line 5 "TestFiles/IntegrationTests/InstrumentationPassIntegrationTest/BasicTest.cshtml"
+__InputTagHelper.BarProp = DateTime.Now;
+
+#line default
+#line hidden
+                __tagHelperExecutionContext.AddTagHelperAttribute("date", __InputTagHelper.BarProp, global::Microsoft.AspNetCore.Razor.TagHelpers.HtmlAttributeValueStyle.DoubleQuotes);
                 __tagHelperExecutionContext.AddHtmlAttribute(__tagHelperAttribute_1);
-                BeginContext(97, 33, false);
+                BeginContext(97, 52, false);
                 await __tagHelperRunner.RunAsync(__tagHelperExecutionContext);
                 if (!__tagHelperExecutionContext.Output.IsContentModified)
                 {
@@ -66,7 +72,7 @@ Write("Hello");
                 Write(__tagHelperExecutionContext.Output);
                 __tagHelperExecutionContext = __tagHelperScopeManager.End();
                 EndContext();
-                BeginContext(130, 2, true);
+                BeginContext(149, 2, true);
                 WriteLiteral("\r\n");
                 EndContext();
             }
@@ -74,7 +80,7 @@ Write("Hello");
             __FormTagHelper = CreateTagHelper<global::FormTagHelper>();
             __tagHelperExecutionContext.Add(__FormTagHelper);
             __tagHelperExecutionContext.AddHtmlAttribute(__tagHelperAttribute_2);
-            BeginContext(71, 68, false);
+            BeginContext(71, 87, false);
             await __tagHelperRunner.RunAsync(__tagHelperExecutionContext);
             if (!__tagHelperExecutionContext.Output.IsContentModified)
             {

test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/InstrumentationPassIntegrationTest/BasicTest.cshtml

@@ -2,5 +2,5 @@
 <span someattr>Hola</span>
 @("Hello")
 <form unbound="foo">
-    <input value=Hello type='text' />
+    <input value=Hello date=@DateTime.Now type='text' />
 </form>

test/Microsoft.AspNetCore.Razor.Evolution.Test/TestFiles/IntegrationTests/InstrumentationPassIntegrationTest/BasicTest.ir.txt

@@ -19,24 +19,27 @@ Document -
                 CSharpStatement -  - BeginContext(69, 2, true);
                 HtmlContent - (69:2,10 [2] BasicTest.cshtml) - \n
                 CSharpStatement -  - EndContext();
-                TagHelper - (71:3,0 [68] BasicTest.cshtml)
+                TagHelper - (71:3,0 [87] BasicTest.cshtml)
                     InitializeTagHelperStructure -  - form - TagMode.StartTagAndEndTag
                         CSharpStatement -  - BeginContext(91, 6, true);
                         HtmlContent - (91:3,20 [6] BasicTest.cshtml) - \n    
                         CSharpStatement -  - EndContext();
-                        TagHelper - (97:4,4 [33] BasicTest.cshtml)
+                        TagHelper - (97:4,4 [52] BasicTest.cshtml)
                             InitializeTagHelperStructure -  - input - TagMode.SelfClosing
                             CreateTagHelper -  - InputTagHelper
                             SetPreallocatedTagHelperProperty -  - __tagHelperAttribute_0 - value - FooProp
+                            SetTagHelperProperty - (121:4,28 [13] BasicTest.cshtml) - date - BarProp - HtmlAttributeValueStyle.DoubleQuotes
+                                CSharpExpression - (122:4,29 [12] BasicTest.cshtml)
+                                    CSharpToken - (122:4,29 [12] BasicTest.cshtml) - DateTime.Now
                             AddPreallocatedTagHelperHtmlAttribute -  - __tagHelperAttribute_1
-                            CSharpStatement -  - BeginContext(97, 33, false);
+                            CSharpStatement -  - BeginContext(97, 52, false);
                             ExecuteTagHelpers - 
                             CSharpStatement -  - EndContext();
-                        CSharpStatement -  - BeginContext(130, 2, true);
+                        CSharpStatement -  - BeginContext(149, 2, true);
-                        HtmlContent - (130:4,37 [2] BasicTest.cshtml) - \n
+                        HtmlContent - (149:4,56 [2] BasicTest.cshtml) - \n
                         CSharpStatement -  - EndContext();
                     CreateTagHelper -  - FormTagHelper
                     AddPreallocatedTagHelperHtmlAttribute -  - __tagHelperAttribute_2
-                    CSharpStatement -  - BeginContext(71, 68, false);
+                    CSharpStatement -  - BeginContext(71, 87, false);
                     ExecuteTagHelpers - 
                     CSharpStatement -  - EndContext();