From 71d3aa3e0936964a24dcad94575da007f8e0f865 Mon Sep 17 00:00:00 2001
From: Doug Bunting <dougbu@microsoft.com>
Date: Thu, 10 Mar 2016 22:07:48 -0800
Subject: [PATCH] Correct HTML and JavaScript encoding of `<link>` and
 `<script>` attribute values - #4083 - `<link>` tag helper did not HTML encode
 `href` values in fallback elements - `<script>` tag helper did not correctly
 encode any attribute value in fallback elements  - e.g. double quotes in
 literal strings would slip through - only needed to change one existing unit
 test (!!); so added a bunch

nit: use `Process()`, not `ProcessAsync()` in `<script>` tag helper tests
---
 .../LinkTagHelper.cs                          |  12 +-
 .../ScriptTagHelper.cs                        |  55 ++++-
 ...Site.HtmlGeneration_Home.Link.Encoded.html |  32 +--
 ...ationWebSite.HtmlGeneration_Home.Link.html |   2 +-
 ...te.HtmlGeneration_Home.Script.Encoded.html |  20 +-
 ...ionWebSite.HtmlGeneration_Home.Script.html |   4 +-
 .../LinkTagHelperTest.cs                      | 192 ++++++++++++++++--
 .../ScriptTagHelperTest.cs                    | 159 ++++++++++++---
 8 files changed, 393 insertions(+), 83 deletions(-)

diff --git a/src/Microsoft.AspNetCore.Mvc.TagHelpers/LinkTagHelper.cs b/src/Microsoft.AspNetCore.Mvc.TagHelpers/LinkTagHelper.cs
index 07c3fdf6af..f3d997d398 100644
--- a/src/Microsoft.AspNetCore.Mvc.TagHelpers/LinkTagHelper.cs
+++ b/src/Microsoft.AspNetCore.Mvc.TagHelpers/LinkTagHelper.cs
@@ -4,14 +4,12 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Text;
 using System.Text.Encodings.Web;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc.Razor.TagHelpers;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.Routing;
 using Microsoft.AspNetCore.Mvc.TagHelpers.Internal;
-using Microsoft.AspNetCore.Mvc.ViewFeatures;
 using Microsoft.AspNetCore.Razor.TagHelpers;
 using Microsoft.Extensions.Caching.Memory;
 
@@ -362,15 +360,21 @@ private void AppendFallbackHrefs(TagHelperContent builder, IReadOnlyList<string>
                     firstAdded = true;
                 }
 
-                // fallbackHrefs come from bound attributes and globbing. Must always be non-null.
+                // fallbackHrefs come from bound attributes (a C# context) and globbing. Must always be non-null.
                 Debug.Assert(fallbackHrefs[i] != null);
+
                 var valueToWrite = fallbackHrefs[i];
                 if (AppendVersion == true)
                 {
                     valueToWrite = _fileVersionProvider.AddFileVersionToPath(fallbackHrefs[i]);
                 }
 
-                builder.AppendHtml(JavaScriptEncoder.Encode(valueToWrite));
+                // Must HTML-encode the href attribute value to ensure the written <link/> element is valid. Must also
+                // JavaScript-encode that value to ensure the doc.write() statement is valid.
+                valueToWrite = HtmlEncoder.Encode(valueToWrite);
+                valueToWrite = JavaScriptEncoder.Encode(valueToWrite);
+
+                builder.AppendHtml(valueToWrite);
                 builder.AppendHtml("\"");
             }
             builder.AppendHtml("]);");
diff --git a/src/Microsoft.AspNetCore.Mvc.TagHelpers/ScriptTagHelper.cs b/src/Microsoft.AspNetCore.Mvc.TagHelpers/ScriptTagHelper.cs
index 96ad174303..799d9d1229 100644
--- a/src/Microsoft.AspNetCore.Mvc.TagHelpers/ScriptTagHelper.cs
+++ b/src/Microsoft.AspNetCore.Mvc.TagHelpers/ScriptTagHelper.cs
@@ -3,8 +3,11 @@
 
 using System;
 using System.Diagnostics;
+using System.IO;
 using System.Text.Encodings.Web;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Html;
+using Microsoft.AspNetCore.Mvc.Razor;
 using Microsoft.AspNetCore.Mvc.Razor.TagHelpers;
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.Routing;
@@ -39,6 +42,7 @@ public class ScriptTagHelper : UrlResolutionTagHelper
         private const string AppendVersionAttributeName = "asp-append-version";
         private static readonly Func<Mode, Mode, int> Compare = (a, b) => a - b;
         private FileVersionProvider _fileVersionProvider;
+        private StringWriter _stringWriter;
 
         private static readonly ModeAttributes<Mode>[] ModeDetails = new[] {
             // Regular src with file version alone
@@ -174,6 +178,20 @@ public override int Order
         // Internal for ease of use when testing.
         protected internal GlobbingUrlBuilder GlobbingUrlBuilder { get; set; }
 
+        // Shared writer for determining the string content of a TagHelperAttribute's Value.
+        private StringWriter StringWriter
+        {
+            get
+            {
+                if (_stringWriter == null)
+                {
+                    _stringWriter = new StringWriter();
+                }
+
+                return _stringWriter;
+            }
+        }
+
         /// <inheritdoc />
         public override void Process(TagHelperContext context, TagHelperOutput output)
         {
@@ -300,7 +318,7 @@ private void BuildFallbackBlock(TagHelperAttributeList attributes, DefaultTagHel
                         if (!attribute.Name.Equals(SrcAttributeName, StringComparison.OrdinalIgnoreCase))
                         {
                             var encodedKey = JavaScriptEncoder.Encode(attribute.Name);
-                            var attributeValue = attribute.Value.ToString();
+                            var attributeValue = GetAttributeValue(attribute.Value);
                             var encodedValue = JavaScriptEncoder.Encode(attributeValue);
 
                             AppendAttribute(builder, encodedKey, encodedValue, escapeQuotes: true);
@@ -324,6 +342,37 @@ private void BuildFallbackBlock(TagHelperAttributeList attributes, DefaultTagHel
             }
         }
 
+        private string GetAttributeValue(object value)
+        {
+            string stringValue;
+            var htmlEncodedString = value as HtmlEncodedString;
+            if (htmlEncodedString != null)
+            {
+                // Value likely came from an HTML context in the .cshtml file but may still contain double quotes
+                // since attribute could have been enclosed in single quotes.
+                stringValue = htmlEncodedString.Value;
+                if (stringValue.Contains("\""))
+                {
+                    stringValue = stringValue.Replace("\"", "&quot;");
+                }
+            }
+            else
+            {
+                var writer = StringWriter;
+                RazorPage.WriteTo(writer, HtmlEncoder, value);
+
+                // Value is now correctly HTML-encoded but may still contain double quotes since attribute could
+                // have been enclosed in single quotes and portions that were HtmlEncodedStrings are not re-encoded.
+                var builder = writer.GetStringBuilder();
+                builder.Replace("\"", "&quot;");
+
+                stringValue = builder.ToString();
+                builder.Clear();
+            }
+
+            return stringValue;
+        }
+
         private void AppendEncodedVersionedSrc(
             string srcName,
             string srcValue,
@@ -337,6 +386,10 @@ private void AppendEncodedVersionedSrc(
 
             if (generateForDocumentWrite)
             {
+                // srcValue comes from a C# context and globbing. Must HTML-encode it to ensure the
+                // written <script/> element is valid. Must also JavaScript-encode that value to ensure
+                // the document.write() statement is valid.
+                srcValue = HtmlEncoder.Encode(srcValue);
                 srcValue = JavaScriptEncoder.Encode(srcValue);
             }
 
diff --git a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
index 27213fd0b4..c87ec590a7 100644
--- a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
+++ b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
@@ -39,63 +39,63 @@
 
     <!-- Fallback to static href -->
     <link href="HtmlEncode[[/styles/site.min.css?a=b&c=d]]" rel="stylesheet" data-extra="test" title="&quot;the&quot; title" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css?a=b&c=d]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css?a=b&c=d]]]]"]);</script>
 
     <!-- Fallback from globbed href to static href -->
     
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback from globbed href with exclude to static href -->
     
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback from globbed and static href to static href -->
     <link href="HtmlEncode[[styles/site.min.css]]" rel="stylesheet" data-extra="test" /><link href="HtmlEncode[[/styles/site.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback from globbed and static href with exclude to static href -->
     <link href="HtmlEncode[[styles/site.min.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback to static href with no primary href -->
     <link rel="stylesheet" data-extra="test">
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback to globbed href -->
     <link href="HtmlEncode[[/styles/site.min.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback to static and globbed href -->
     <link href="HtmlEncode[[/styles/site.min.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]","JavaScriptEncode[[/styles/sub/site2.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]","JavaScriptEncode[[HtmlEncode[[/styles/sub/site2.css]]]]"]);</script>
 
     <!-- Fallback to static and globbed href should dedupe -->
     <link href="HtmlEncode[[/styles/site.min.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback to static and globbed href with exclude -->
     <link href="HtmlEncode[[/styles/site.min.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]","JavaScriptEncode[[/styles/sub/site2.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]","JavaScriptEncode[[HtmlEncode[[/styles/sub/site2.css]]]]"]);</script>
 
     <!-- Fallback from globbed href to glbobed href -->
     
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback from globbed href with exclude to globbed href -->
     
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback from globbed and static href to globbed href -->
     <link href="HtmlEncode[[styles/site.min.css]]" rel="stylesheet" data-extra="test" /><link href="HtmlEncode[[/styles/site.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Fallback from globbed and static href with exclude to globbed href -->
     <link href="HtmlEncode[[styles/site.min.css]]" rel="stylesheet" data-extra="test">
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"]);</script>
 
     <!-- Kitchen sink, all the attributes -->
     <link href="HtmlEncode[[styles/site.min.css]]" rel="stylesheet" data-extra="test" />
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css]]","JavaScriptEncode[[/styles/sub/site2.css]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]","JavaScriptEncode[[HtmlEncode[[/styles/sub/site2.css]]]]"]);</script>
 
     <!-- Fallback to globbed href that doesn't exist -->
     <link href="HtmlEncode[[/styles/site.min.css]]" rel="stylesheet" data-extra="test" />
@@ -120,7 +120,7 @@
 
     <!-- Fallback with file version -->
     <link href="HtmlEncode[[/styles/site.min.css]]" rel="stylesheet" data-extra="test">
-<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]]]"]);</script>
 
     <!-- Globbed link tag with existing file, static href and file version -->
     <link href="HtmlEncode[[/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]" rel="stylesheet" /><link href="HtmlEncode[[/styles/sub/site2.css?v=30cxPex0tA9xEatW7f1Qhnn8tVLAHgE6xwIZhESq0y0]]" rel="stylesheet" /><link href="HtmlEncode[[/styles/sub/site3.css?v=fSxxOr1Q4Dq2uPuzlju5UYGuK0SKABI-ghvaIGEsZDc]]" rel="stylesheet" /><link href="HtmlEncode[[/styles/sub/site3.min.css?v=s8JMmAZxBn0dzuhRtQ0wgOvNBK4XRJRWEC2wfzsVF9M]]" rel="stylesheet" />
diff --git a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
index 585cf17fc6..0384f385c8 100644
--- a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
+++ b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
@@ -39,7 +39,7 @@
 
     <!-- Fallback to static href -->
     <link href="/styles/site.min.css?a=b&amp;c=d" rel="stylesheet" data-extra="test" title="&quot;the&quot; title" />
-<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("visibility","hidden",["\/styles\/site.css?a=b\u0026c=d"]);</script>
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName("SCRIPT"),g=f[f.length-1].previousElementSibling,h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel="stylesheet" href="'+c[d]+'"/>')}("visibility","hidden",["\/styles\/site.css?a=b\u0026amp;c=d"]);</script>
 
     <!-- Fallback from globbed href to static href -->
     
diff --git a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html
index 433539425e..f696105479 100644
--- a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html
+++ b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html
@@ -1,4 +1,4 @@
-<!doctype html>
+<!doctype html>
 <html>
 <head>
     <meta charset="utf-8" />
@@ -13,27 +13,27 @@ <h2>Script tag helper test</h2>
     <script src="HtmlEncode[[/blank.js?a=b&c=d]]" data-foo="foo-data2" title="&lt;the title>">
         // TagHelper script with comment in body, and extra properties.
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js?a=b&c=d]]\" JavaScriptEncode[[data-foo]]=\"JavaScriptEncode[[foo-data2]]\" JavaScriptEncode[[title]]=\"JavaScriptEncode[[&lt;the title>]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js?a=b&c=d]]]]\" JavaScriptEncode[[data-foo]]=\"JavaScriptEncode[[foo-data2]]\" JavaScriptEncode[[title]]=\"JavaScriptEncode[[&lt;the title>]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]" title="&quot;the&quot; title">
         // Fallback to globbed src
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js]]\" JavaScriptEncode[[title]]=\"JavaScriptEncode[["the" title]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js]]]]\" JavaScriptEncode[[title]]=\"JavaScriptEncode[[&quot;the&quot; title]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to globbed src with exclude
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js]]\"><\/script><script src=\"JavaScriptEncode[[/styles/sub/site2.js]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js]]]]\"><\/script><script src=\"JavaScriptEncode[[HtmlEncode[[/styles/sub/site2.js]]]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to globbed and static src
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js]]\"><\/script><script src=\"JavaScriptEncode[[/styles/sub/site2.js]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js]]]]\"><\/script><script src=\"JavaScriptEncode[[HtmlEncode[[/styles/sub/site2.js]]]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to globbed and static src should de-dupe
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js]]]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to globbed src with missing include
@@ -42,7 +42,7 @@ <h2>Script tag helper test</h2>
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to static and globbed src with missing include
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js]]]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to globbed src outside of webroot
@@ -55,7 +55,7 @@ <h2>Script tag helper test</h2>
     <script data-foo="foo-data3">
         // Valid TagHelper (although no src is provided) script with comment in body, and extra properties.
     </script>
-<script>(false||document.write("<script JavaScriptEncode[[data-foo]]=\"JavaScriptEncode[[foo-data3]]\" src=\"JavaScriptEncode[[/styles/site.js]]\"><\/script>"));</script>
+<script>(false||document.write("<script JavaScriptEncode[[data-foo]]=\"JavaScriptEncode[[foo-data3]]\" src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js]]]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Invalid TagHelper script with comment in body.
@@ -98,12 +98,12 @@ <h2>Script tag helper test</h2>
     <script src="HtmlEncode[[/blank.js]]">
         // TagHelper script with comment in body, and file version.
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js?v=jx1PJjLX32-xgQQx2BxnckU9QH9DVKkm4-M5bSK869I]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js?v=jx1PJjLX32-xgQQx2BxnckU9QH9DVKkm4-M5bSK869I]]]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to globbed src with file version.
     </script>
-<script>(false||document.write("<script src=\"JavaScriptEncode[[/styles/site.js?v=jx1PJjLX32-xgQQx2BxnckU9QH9DVKkm4-M5bSK869I]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[HtmlEncode[[/styles/site.js?v=jx1PJjLX32-xgQQx2BxnckU9QH9DVKkm4-M5bSK869I]]]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/styles/site.js?v=jx1PJjLX32-xgQQx2BxnckU9QH9DVKkm4-M5bSK869I]]">
         // Regular script with comment in body, and file version.
diff --git a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html
index 69adf8e151..823c1f2e00 100644
--- a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html
+++ b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html
@@ -13,12 +13,12 @@ <h2>Script tag helper test</h2>
     <script src="/blank.js?a=b&amp;c=d" data-foo="foo-data2" title="&lt;the title>">
         // TagHelper script with comment in body, and extra properties.
     </script>
-<script>(false||document.write("<script src=\"\/styles\/site.js?a=b\u0026c=d\" data-foo=\"foo-data2\" title=\"\u0026lt;the title\u003E\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"\/styles\/site.js?a=b\u0026amp;c=d\" data-foo=\"foo-data2\" title=\"\u0026lt;the title\u003E\"><\/script>"));</script>
 
     <script src="/blank.js" title="&quot;the&quot; title">
         // Fallback to globbed src
     </script>
-<script>(false||document.write("<script src=\"\/styles\/site.js\" title=\"\u0022the\u0022 title\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"\/styles\/site.js\" title=\"\u0026quot;the\u0026quot; title\"><\/script>"));</script>
 
     <script src="/blank.js">
         // Fallback to globbed src with exclude
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
index 5d55379a80..acc6eaefb8 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
@@ -16,6 +16,7 @@
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.Routing;
 using Microsoft.AspNetCore.Mvc.TagHelpers.Internal;
+using Microsoft.AspNetCore.Mvc.TestCommon;
 using Microsoft.AspNetCore.Mvc.ViewEngines;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
 using Microsoft.AspNetCore.Razor.TagHelpers;
@@ -403,6 +404,7 @@ public void RunsWhenRequiredAttributesArePresent_NoHref(
             // Assert
             Assert.Null(output.TagName);
             Assert.True(output.IsContentModified);
+            Assert.True(output.Content.IsEmpty);
             Assert.True(output.PostElement.IsModified);
         }
 
@@ -595,6 +597,8 @@ public void DoesNotRunWhenAllRequiredAttributesAreMissing()
         public void RendersLinkTagsForGlobbedHrefResults()
         {
             // Arrange
+            var expectedContent = "<link rel=\"stylesheet\" href=\"HtmlEncode[[/css/site.css]]\" />" +
+                "<link rel=\"stylesheet\" href=\"HtmlEncode[[/base.css]]\" />";
             var context = MakeTagHelperContext(
                 attributes: new TagHelperAttributeList
                 {
@@ -634,24 +638,41 @@ public void RendersLinkTagsForGlobbedHrefResults()
             // Assert
             Assert.Equal("link", output.TagName);
             Assert.Equal("/css/site.css", output.Attributes["href"].Value);
-            Assert.Equal("<link rel=\"stylesheet\" href=\"HtmlEncode[[/base.css]]\" />", output.PostElement.GetContent());
+            var content = HtmlContentUtilities.HtmlContentToString(output, new HtmlTestEncoder());
+            Assert.Equal(expectedContent, content);
         }
 
         [Fact]
-        public void RendersLinkTagsForGlobbedHrefResults_UsingProvidedEncoder()
+        public void RendersLinkTagsForGlobbedHrefResults_EncodesAsExpected()
         {
             // Arrange
+            var expectedContent =
+                "<link encoded=\"contains &quot;quotes&quot;\" href=\"HtmlEncode[[/css/site.css]]\" " +
+                "literal=\"HtmlEncode[[all HTML encoded]]\" " +
+                "mixed=\"HtmlEncode[[HTML encoded]] and contains &quot;quotes&quot;\" />" +
+                "<link encoded=\"contains &quot;quotes&quot;\" href=\"HtmlEncode[[/base.css]]\" " +
+                "literal=\"HtmlEncode[[all HTML encoded]]\" " +
+                "mixed=\"HtmlEncode[[HTML encoded]] and contains &quot;quotes&quot;\" />";
+            var mixed = new DefaultTagHelperContent();
+            mixed.Append("HTML encoded");
+            mixed.AppendHtml(" and contains \"quotes\"");
             var context = MakeTagHelperContext(
                 attributes: new TagHelperAttributeList
                 {
-                    new TagHelperAttribute("rel", "stylesheet"),
-                    new TagHelperAttribute("href", "/css/site.css"),
-                    new TagHelperAttribute("asp-href-include", "**/*.css")
+                    { "asp-href-include", "**/*.css" },
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "href", "/css/site.css" },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                });
+            var output = MakeTagHelperOutput(
+                "link",
+                attributes: new TagHelperAttributeList
+                {
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
                 });
-            var output = MakeTagHelperOutput("link", attributes: new TagHelperAttributeList
-            {
-                new TagHelperAttribute("rel", "stylesheet"),
-            });
             var hostingEnvironment = MakeHostingEnvironment();
             var viewContext = MakeViewContext();
             var globbingUrlBuilder = new Mock<GlobbingUrlBuilder>(
@@ -669,9 +690,9 @@ public void RendersLinkTagsForGlobbedHrefResults_UsingProvidedEncoder()
                 MakeUrlHelperFactory())
             {
                 GlobbingUrlBuilder = globbingUrlBuilder.Object,
-                ViewContext = viewContext,
                 Href = "/css/site.css",
                 HrefInclude = "**/*.css",
+                ViewContext = viewContext,
             };
 
             // Act
@@ -680,12 +701,12 @@ public void RendersLinkTagsForGlobbedHrefResults_UsingProvidedEncoder()
             // Assert
             Assert.Equal("link", output.TagName);
             Assert.Equal("/css/site.css", output.Attributes["href"].Value);
-            Assert.Equal("<link rel=\"HtmlEncode[[stylesheet]]\" href=\"HtmlEncode[[/base.css]]\" />",
-                output.PostElement.GetContent());
+            var content = HtmlContentUtilities.HtmlContentToString(output, new HtmlTestEncoder());
+            Assert.Equal(expectedContent, content);
         }
 
         [Fact]
-        public void RendersLinkTags_AddsFileVersion()
+        public void RendersLinkTags_WithFileVersion()
         {
             // Arrange
             var context = MakeTagHelperContext(
@@ -723,7 +744,7 @@ public void RendersLinkTags_AddsFileVersion()
         }
 
         [Fact]
-        public void RendersLinkTags_AddsFileVersion_WithRequestPathBase()
+        public void RendersLinkTags_WithFileVersion_AndRequestPathBase()
         {
             // Arrange
             var context = MakeTagHelperContext(
@@ -761,7 +782,143 @@ public void RendersLinkTags_AddsFileVersion_WithRequestPathBase()
         }
 
         [Fact]
-        public void RendersLinkTags_GlobbedHref_AddsFileVersion()
+        public void RenderLinkTags_FallbackHref_WithFileVersion()
+        {
+            // Arrange
+            var expectedPostElement = Environment.NewLine +
+                "<meta name=\"x-stylesheet-fallback-test\" content=\"\" class=\"hidden\" />" +
+                "<script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName(\"SCRIPT\")," +
+                "g=f[f.length-1].previousElementSibling," +
+                "h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;" +
+                "if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel=\"stylesheet\" href=\"'+c[d]+'\"/>')}(" +
+                "\"JavaScriptEncode[[visibility]]\",\"JavaScriptEncode[[hidden]]\"," +
+                "[\"JavaScriptEncode[[HtmlEncode[[/fallback.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]]]\"]);" +
+                "</script>";
+            var context = MakeTagHelperContext(
+                attributes: new TagHelperAttributeList
+                {
+                    { "asp-append-version", "true" },
+                    { "asp-fallback-href-include", "**/fallback.css" },
+                    { "asp-fallback-test-class", "hidden" },
+                    { "asp-fallback-test-property", "visibility" },
+                    { "asp-fallback-test-value", "hidden" },
+                    { "href", "/css/site.css" },
+                });
+            var output = MakeTagHelperOutput("link", attributes: new TagHelperAttributeList());
+            var hostingEnvironment = MakeHostingEnvironment();
+            var viewContext = MakeViewContext();
+            var globbingUrlBuilder = new Mock<GlobbingUrlBuilder>(
+                new TestFileProvider(),
+                Mock.Of<IMemoryCache>(),
+                PathString.Empty);
+            globbingUrlBuilder.Setup(g => g.BuildUrlList(null, "**/fallback.css", null))
+                .Returns(new[] { "/fallback.css" });
+
+            var helper = new LinkTagHelper(
+                MakeHostingEnvironment(),
+                MakeCache(),
+                new HtmlTestEncoder(),
+                new JavaScriptTestEncoder(),
+                MakeUrlHelperFactory())
+            {
+                AppendVersion = true,
+                Href = "/css/site.css",
+                FallbackHrefInclude = "**/fallback.css",
+                FallbackTestClass = "hidden",
+                FallbackTestProperty = "visibility",
+                FallbackTestValue = "hidden",
+                GlobbingUrlBuilder = globbingUrlBuilder.Object,
+                ViewContext = viewContext,
+            };
+
+            // Act
+            helper.Process(context, output);
+
+            // Assert
+            Assert.Equal("link", output.TagName);
+            Assert.Equal("/css/site.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk", output.Attributes["href"].Value);
+            Assert.Equal(expectedPostElement, output.PostElement.GetContent());
+        }
+
+        [Fact]
+        public void RenderLinkTags_FallbackHref_WithFileVersion_EncodesAsExpected()
+        {
+            // Arrange
+            var expectedContent = "<link encoded=\"contains &quot;quotes&quot;\" " +
+                "href=\"HtmlEncode[[/css/site.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]\" " +
+                "literal=\"HtmlEncode[[all HTML encoded]]\" " +
+                "mixed=\"HtmlEncode[[HTML encoded]] and contains &quot;quotes&quot;\" />" +
+                Environment.NewLine +
+                "<meta name=\"x-stylesheet-fallback-test\" content=\"\" class=\"HtmlEncode[[hidden]]\" />" +
+                "<script>!function(a,b,c){var d,e=document,f=e.getElementsByTagName(\"SCRIPT\")," +
+                "g=f[f.length-1].previousElementSibling," +
+                "h=e.defaultView&&e.defaultView.getComputedStyle?e.defaultView.getComputedStyle(g):g.currentStyle;" +
+                "if(h&&h[a]!==b)for(d=0;d<c.length;d++)e.write('<link rel=\"stylesheet\" href=\"'+c[d]+'\"/>')}(" +
+                "\"JavaScriptEncode[[visibility]]\",\"JavaScriptEncode[[hidden]]\"," +
+                "[\"JavaScriptEncode[[HtmlEncode[[/fallback.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]]]\"]);" +
+                "</script>";
+            var mixed = new DefaultTagHelperContent();
+            mixed.Append("HTML encoded");
+            mixed.AppendHtml(" and contains \"quotes\"");
+            var context = MakeTagHelperContext(
+                attributes: new TagHelperAttributeList
+                {
+                    { "asp-append-version", "true" },
+                    { "asp-fallback-href-include", "**/fallback.css" },
+                    { "asp-fallback-test-class", "hidden" },
+                    { "asp-fallback-test-property", "visibility" },
+                    { "asp-fallback-test-value", "hidden" },
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "href", "/css/site.css" },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                });
+            var output = MakeTagHelperOutput(
+                "link",
+                attributes: new TagHelperAttributeList
+                {
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                });
+            var hostingEnvironment = MakeHostingEnvironment();
+            var viewContext = MakeViewContext();
+            var globbingUrlBuilder = new Mock<GlobbingUrlBuilder>(
+                new TestFileProvider(),
+                Mock.Of<IMemoryCache>(),
+                PathString.Empty);
+            globbingUrlBuilder.Setup(g => g.BuildUrlList(null, "**/fallback.css", null))
+                .Returns(new[] { "/fallback.css" });
+
+            var helper = new LinkTagHelper(
+                MakeHostingEnvironment(),
+                MakeCache(),
+                new HtmlTestEncoder(),
+                new JavaScriptTestEncoder(),
+                MakeUrlHelperFactory())
+            {
+                AppendVersion = true,
+                FallbackHrefInclude = "**/fallback.css",
+                FallbackTestClass = "hidden",
+                FallbackTestProperty = "visibility",
+                FallbackTestValue = "hidden",
+                GlobbingUrlBuilder = globbingUrlBuilder.Object,
+                Href = "/css/site.css",
+                ViewContext = viewContext,
+            };
+
+            // Act
+            helper.Process(context, output);
+
+            // Assert
+            Assert.Equal("link", output.TagName);
+            Assert.Equal("/css/site.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk", output.Attributes["href"].Value);
+            var content = HtmlContentUtilities.HtmlContentToString(output, new HtmlTestEncoder());
+            Assert.Equal(expectedContent, content);
+        }
+
+        [Fact]
+        public void RendersLinkTags_GlobbedHref_WithFileVersion()
         {
             // Arrange
             var context = MakeTagHelperContext(
@@ -848,7 +1005,10 @@ private static TagHelperOutput MakeTagHelperOutput(string tagName, TagHelperAttr
                 tagName,
                 attributes,
                 getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(
-                    new DefaultTagHelperContent()));
+                    new DefaultTagHelperContent()))
+            {
+                TagMode = TagMode.SelfClosing,
+            };
         }
 
         private static IHostingEnvironment MakeHostingEnvironment()
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
index 95286d9a76..05c280f14a 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
@@ -16,6 +16,7 @@
 using Microsoft.AspNetCore.Mvc.Rendering;
 using Microsoft.AspNetCore.Mvc.Routing;
 using Microsoft.AspNetCore.Mvc.TagHelpers.Internal;
+using Microsoft.AspNetCore.Mvc.TestCommon;
 using Microsoft.AspNetCore.Mvc.ViewEngines;
 using Microsoft.AspNetCore.Mvc.ViewFeatures;
 using Microsoft.AspNetCore.Razor.TagHelpers;
@@ -95,7 +96,7 @@ public void Process_SrcDefaultsToTagHelperOutputSrcAttributeAddedByOtherTagHelpe
 
         [Theory]
         [MemberData(nameof(LinkTagHelperTest.MultiAttributeSameNameData), MemberType = typeof(LinkTagHelperTest))]
-        public async Task HandlesMultipleAttributesSameNameCorrectly(TagHelperAttributeList outputAttributes)
+        public void HandlesMultipleAttributesSameNameCorrectly(TagHelperAttributeList outputAttributes)
         {
             // Arrange
             var allAttributes = new TagHelperAttributeList(
@@ -134,7 +135,7 @@ public async Task HandlesMultipleAttributesSameNameCorrectly(TagHelperAttributeL
             expectedAttributes.Add(new TagHelperAttribute("src", "/blank.js"));
 
             // Act
-            await helper.ProcessAsync(tagHelperContext, output);
+            helper.Process(tagHelperContext, output);
 
             // Assert
             Assert.Equal(expectedAttributes, output.Attributes);
@@ -265,7 +266,7 @@ public static TheoryData RunsWhenRequiredAttributesArePresent_Data
 
         [Theory]
         [MemberData(nameof(RunsWhenRequiredAttributesArePresent_Data))]
-        public async Task RunsWhenRequiredAttributesArePresent(
+        public void RunsWhenRequiredAttributesArePresent(
             TagHelperAttributeList attributes,
             Action<ScriptTagHelper> setProperties)
         {
@@ -294,7 +295,7 @@ public async Task RunsWhenRequiredAttributesArePresent(
             setProperties(helper);
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
 
             // Assert
             Assert.NotNull(output.TagName);
@@ -362,7 +363,7 @@ public static TheoryData RunsWhenRequiredAttributesArePresent_NoSrc_Data
 
         [Theory]
         [MemberData(nameof(RunsWhenRequiredAttributesArePresent_NoSrc_Data))]
-        public async Task RunsWhenRequiredAttributesArePresent_NoSrc(
+        public void RunsWhenRequiredAttributesArePresent_NoSrc(
             TagHelperAttributeList attributes,
             Action<ScriptTagHelper> setProperties)
         {
@@ -391,11 +392,12 @@ public async Task RunsWhenRequiredAttributesArePresent_NoSrc(
             setProperties(helper);
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
 
             // Assert
             Assert.Null(output.TagName);
             Assert.True(output.IsContentModified);
+            Assert.True(output.Content.IsEmpty);
             Assert.True(output.PostElement.IsModified);
         }
 
@@ -498,7 +500,7 @@ public void DoesNotRunWhenARequiredAttributeIsMissing(
         }
 
         [Fact]
-        public async Task DoesNotRunWhenAllRequiredAttributesAreMissing()
+        public void DoesNotRunWhenAllRequiredAttributesAreMissing()
         {
             // Arrange
             var tagHelperContext = MakeTagHelperContext();
@@ -516,7 +518,7 @@ public async Task DoesNotRunWhenAllRequiredAttributesAreMissing()
             };
 
             // Act
-            await helper.ProcessAsync(tagHelperContext, output);
+            helper.Process(tagHelperContext, output);
 
             // Assert
             Assert.Equal("script", output.TagName);
@@ -526,7 +528,7 @@ public async Task DoesNotRunWhenAllRequiredAttributesAreMissing()
         }
 
         [Fact]
-        public async Task PreservesOrderOfNonSrcAttributes()
+        public void PreservesOrderOfNonSrcAttributes()
         {
             // Arrange
             var tagHelperContext = MakeTagHelperContext(
@@ -564,7 +566,7 @@ public async Task PreservesOrderOfNonSrcAttributes()
             };
 
             // Act
-            await helper.ProcessAsync(tagHelperContext, output);
+            helper.Process(tagHelperContext, output);
 
             // Assert
             Assert.Equal("data-extra", output.Attributes[0].Name);
@@ -573,9 +575,11 @@ public async Task PreservesOrderOfNonSrcAttributes()
         }
 
         [Fact]
-        public async Task RendersScriptTagsForGlobbedSrcResults()
+        public void RendersScriptTagsForGlobbedSrcResults()
         {
             // Arrange
+            var expectedContent = "<script src=\"HtmlEncode[[/js/site.js]]\"></script>" +
+                "<script src=\"HtmlEncode[[/common.js]]\"></script>";
             var context = MakeTagHelperContext(
                 attributes: new TagHelperAttributeList
                 {
@@ -606,25 +610,46 @@ public async Task RendersScriptTagsForGlobbedSrcResults()
             };
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
 
             // Assert
             Assert.Equal("script", output.TagName);
             Assert.Equal("/js/site.js", output.Attributes["src"].Value);
-            Assert.Equal("<script src=\"HtmlEncode[[/common.js]]\"></script>", output.PostElement.GetContent());
+            var content = HtmlContentUtilities.HtmlContentToString(output, new HtmlTestEncoder());
+            Assert.Equal(expectedContent, content);
         }
 
         [Fact]
-        public async Task RendersScriptTagsForGlobbedSrcResults_UsesProvidedEncoder()
+        public void RendersScriptTagsForGlobbedSrcResults_EncodesAsExpected()
         {
             // Arrange
+            var expectedContent =
+                "<script encoded=\"contains &quot;quotes&quot;\" literal=\"HtmlEncode[[all HTML encoded]]\" " +
+                "mixed=\"HtmlEncode[[HTML encoded]] and contains &quot;quotes&quot;\" " +
+                "src=\"HtmlEncode[[/js/site.js]]\"></script>" +
+                "<script encoded=\"contains &quot;quotes&quot;\" literal=\"HtmlEncode[[all HTML encoded]]\" " +
+                "mixed=\"HtmlEncode[[HTML encoded]] and contains &quot;quotes&quot;\" " +
+                "src=\"HtmlEncode[[/common.js]]\"></script>";
+            var mixed = new DefaultTagHelperContent();
+            mixed.Append("HTML encoded");
+            mixed.AppendHtml(" and contains \"quotes\"");
             var context = MakeTagHelperContext(
                 attributes: new TagHelperAttributeList
                 {
-                    new TagHelperAttribute("src", "/js/site.js"),
-                    new TagHelperAttribute("asp-src-include", "**/*.js")
+                    { "asp-src-include", "**/*.js" },
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                    { "src", "/js/site.js" },
+                });
+            var output = MakeTagHelperOutput(
+                "script",
+                attributes: new TagHelperAttributeList
+                {
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "literal", "all HTML encoded"},
+                    { "mixed", mixed},
                 });
-            var output = MakeTagHelperOutput("script", attributes: new TagHelperAttributeList());
             var hostingEnvironment = MakeHostingEnvironment();
             var viewContext = MakeViewContext();
             var globbingUrlBuilder = new Mock<GlobbingUrlBuilder>(
@@ -642,22 +667,23 @@ public async Task RendersScriptTagsForGlobbedSrcResults_UsesProvidedEncoder()
                 MakeUrlHelperFactory())
             {
                 GlobbingUrlBuilder = globbingUrlBuilder.Object,
-                ViewContext = viewContext,
                 Src = "/js/site.js",
                 SrcInclude = "**/*.js",
+                ViewContext = viewContext,
             };
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
 
             // Assert
             Assert.Equal("script", output.TagName);
             Assert.Equal("/js/site.js", output.Attributes["src"].Value);
-            Assert.Equal("<script src=\"HtmlEncode[[/common.js]]\"></script>", output.PostElement.GetContent());
+            var content = HtmlContentUtilities.HtmlContentToString(output, new HtmlTestEncoder());
+            Assert.Equal(expectedContent, content);
         }
 
         [Fact]
-        public async Task RenderScriptTags_WithFileVersion()
+        public void RenderScriptTags_WithFileVersion()
         {
             // Arrange
             var context = MakeTagHelperContext(
@@ -684,7 +710,7 @@ public async Task RenderScriptTags_WithFileVersion()
             };
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
 
             // Assert
             Assert.Equal("script", output.TagName);
@@ -692,7 +718,7 @@ public async Task RenderScriptTags_WithFileVersion()
         }
 
         [Fact]
-        public async Task RenderScriptTags_WithFileVersion_AndRequestPathBase()
+        public void RenderScriptTags_WithFileVersion_AndRequestPathBase()
         {
             // Arrange
             var context = MakeTagHelperContext(
@@ -718,7 +744,7 @@ public async Task RenderScriptTags_WithFileVersion_AndRequestPathBase()
             };
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
 
             // Assert
             Assert.Equal("script", output.TagName);
@@ -726,7 +752,7 @@ public async Task RenderScriptTags_WithFileVersion_AndRequestPathBase()
         }
 
         [Fact]
-        public async Task RenderScriptTags_FallbackSrc_WithFileVersion()
+        public void RenderScriptTags_FallbackSrc_WithFileVersion()
         {
             // Arrange
             var context = MakeTagHelperContext(
@@ -756,20 +782,87 @@ public async Task RenderScriptTags_FallbackSrc_WithFileVersion()
             };
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
+
+            // Assert
+            Assert.Equal("script", output.TagName);
+            Assert.Equal("/js/site.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk", output.Attributes["src"].Value);
+            Assert.Equal(Environment.NewLine + "<script>(isavailable()||document.write(\"<script src=" +
+                "\\\"JavaScriptEncode[[HtmlEncode[[fallback.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]]]\\\"" +
+                "><\\/script>\"));</script>", output.PostElement.GetContent());
+        }
+
+        [Fact]
+        public void RenderScriptTags_FallbackSrc_WithFileVersion_EncodesAsExpected()
+        {
+            // Arrange
+            var expectedContent =
+                "<script encoded=\"contains &quot;quotes&quot;\" literal=\"HtmlEncode[[all HTML encoded]]\" " +
+                "mixed=\"HtmlEncode[[HTML encoded]] and contains &quot;quotes&quot;\" " +
+                "src=\"HtmlEncode[[/js/site.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]\"></script>" +
+                Environment.NewLine +
+                "<script>(isavailable()||document.write(\"<script " +
+                "JavaScriptEncode[[encoded]]=\\\"JavaScriptEncode[[contains &quot;quotes&quot;]]\\\" " +
+                "JavaScriptEncode[[literal]]=\\\"JavaScriptEncode[[HtmlEncode[[all HTML encoded]]]]\\\" " +
+                "JavaScriptEncode[[mixed]]=\\\"JavaScriptEncode[[HtmlEncode[[HTML encoded]] and contains &quot;quotes&quot;]]\\\" " +
+                "src=\\\"JavaScriptEncode[[HtmlEncode[[fallback.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]]]\\\">" +
+                "<\\/script>\"));</script>";
+            var mixed = new DefaultTagHelperContent();
+            mixed.Append("HTML encoded");
+            mixed.AppendHtml(" and contains \"quotes\"");
+            var context = MakeTagHelperContext(
+                attributes: new TagHelperAttributeList
+                {
+                    { "asp-append-version", "true" },
+                    { "asp-fallback-src-include", "fallback.js" },
+                    { "asp-fallback-test", "isavailable()" },
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                    { "src", "/js/site.js" },
+                });
+            var output = MakeTagHelperOutput(
+                "script",
+                attributes: new TagHelperAttributeList
+                {
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                });
+            var hostingEnvironment = MakeHostingEnvironment();
+            var viewContext = MakeViewContext();
+
+            var helper = new ScriptTagHelper(
+                MakeHostingEnvironment(),
+                MakeCache(),
+                new HtmlTestEncoder(),
+                new JavaScriptTestEncoder(),
+                MakeUrlHelperFactory())
+            {
+                AppendVersion = true,
+                FallbackSrc = "fallback.js",
+                FallbackTestExpression = "isavailable()",
+                Src = "/js/site.js",
+                ViewContext = viewContext,
+            };
+
+            // Act
+            helper.Process(context, output);
 
             // Assert
             Assert.Equal("script", output.TagName);
             Assert.Equal("/js/site.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk", output.Attributes["src"].Value);
-            Assert.Equal(Environment.NewLine + "<script>(isavailable()||document.write(\"<script " +
-                "src=\\\"JavaScriptEncode[[fallback.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]\\\">" +
-                "<\\/script>\"));</script>", output.PostElement.GetContent());
+            var content = HtmlContentUtilities.HtmlContentToString(output, new HtmlTestEncoder());
+            Assert.Equal(expectedContent, content);
         }
 
         [Fact]
-        public async Task RenderScriptTags_GlobbedSrc_WithFileVersion()
+        public void RenderScriptTags_GlobbedSrc_WithFileVersion()
         {
             // Arrange
+            var expectedContent = "<script " +
+                "src=\"HtmlEncode[[/js/site.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]\"></script>" +
+                "<script src=\"HtmlEncode[[/common.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]\"></script>";
             var context = MakeTagHelperContext(
                 attributes: new TagHelperAttributeList
                 {
@@ -802,13 +895,13 @@ public async Task RenderScriptTags_GlobbedSrc_WithFileVersion()
             };
 
             // Act
-            await helper.ProcessAsync(context, output);
+            helper.Process(context, output);
 
             // Assert
             Assert.Equal("script", output.TagName);
             Assert.Equal("/js/site.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk", output.Attributes["src"].Value);
-            Assert.Equal("<script src=\"HtmlEncode[[/common.js?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]\">" +
-                "</script>", output.PostElement.GetContent());
+            var content = HtmlContentUtilities.HtmlContentToString(output, new HtmlTestEncoder());
+            Assert.Equal(expectedContent, content);
         }
 
         private TagHelperContext MakeTagHelperContext(