From f66003c8118cc8c7ca21df09c060e08151a3672c Mon Sep 17 00:00:00 2001
From: Sergey Kalinichenko <dasblinkenlight@outlook.com>
Date: Sun, 15 Oct 2023 19:47:12 -0400
Subject: [PATCH 1/4] Supporting pseudo-element attribute in css link fallback
 (#38146)

---
 src/Mvc/Mvc.TagHelpers/src/LinkTagHelper.cs   |  28 +-
 .../src/PublicAPI.Unshipped.txt               |   2 +
 ...kTagHelper_FallbackWithPseudoJavaScript.js |   1 +
 .../Mvc.TagHelpers/test/LinkTagHelperTest.cs  | 313 ++++++++++++++++++
 ...Site.HtmlGeneration_Home.Link.Encoded.html |  75 +++++
 ...ationWebSite.HtmlGeneration_Home.Link.html |  76 +++++
 .../Views/HtmlGeneration_Home/Link.cshtml     | 167 ++++++++++
 7 files changed, 659 insertions(+), 3 deletions(-)
 create mode 100644 src/Mvc/Mvc.TagHelpers/src/compiler/resources/LinkTagHelper_FallbackWithPseudoJavaScript.js

diff --git a/src/Mvc/Mvc.TagHelpers/src/LinkTagHelper.cs b/src/Mvc/Mvc.TagHelpers/src/LinkTagHelper.cs
index f7950deae6d6..f5535b7745cd 100644
--- a/src/Mvc/Mvc.TagHelpers/src/LinkTagHelper.cs
+++ b/src/Mvc/Mvc.TagHelpers/src/LinkTagHelper.cs
@@ -29,12 +29,15 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers;
 [HtmlTargetElement("link", Attributes = FallbackHrefExcludeAttributeName, TagStructure = TagStructure.WithoutEndTag)]
 [HtmlTargetElement("link", Attributes = FallbackTestClassAttributeName, TagStructure = TagStructure.WithoutEndTag)]
 [HtmlTargetElement("link", Attributes = FallbackTestPropertyAttributeName, TagStructure = TagStructure.WithoutEndTag)]
+[HtmlTargetElement("link", Attributes = FallbackTestPseudoElementAttributeName, TagStructure = TagStructure.WithoutEndTag)]
 [HtmlTargetElement("link", Attributes = FallbackTestValueAttributeName, TagStructure = TagStructure.WithoutEndTag)]
 [HtmlTargetElement("link", Attributes = AppendVersionAttributeName, TagStructure = TagStructure.WithoutEndTag)]
 public class LinkTagHelper : UrlResolutionTagHelper
 {
     private static readonly string FallbackJavaScriptResourceName =
         typeof(LinkTagHelper).Namespace + ".compiler.resources.LinkTagHelper_FallbackJavaScript.js";
+    private static readonly string FallbackWithPseudoJavaScriptResourceName =
+        typeof(LinkTagHelper).Namespace + ".compiler.resources.LinkTagHelper_FallbackWithPseudoJavaScript.js";
 
     private const string HrefIncludeAttributeName = "asp-href-include";
     private const string HrefExcludeAttributeName = "asp-href-exclude";
@@ -44,6 +47,7 @@ public class LinkTagHelper : UrlResolutionTagHelper
     private const string FallbackHrefExcludeAttributeName = "asp-fallback-href-exclude";
     private const string FallbackTestClassAttributeName = "asp-fallback-test-class";
     private const string FallbackTestPropertyAttributeName = "asp-fallback-test-property";
+    private const string FallbackTestPseudoElementAttributeName = "asp-fallback-test-pseudo-element";
     private const string FallbackTestValueAttributeName = "asp-fallback-test-value";
     private const string AppendVersionAttributeName = "asp-append-version";
     private const string HrefAttributeName = "href";
@@ -199,6 +203,14 @@ public LinkTagHelper(
     [HtmlAttributeName(FallbackTestPropertyAttributeName)]
     public string FallbackTestProperty { get; set; }
 
+    /// <summary>
+    /// The CSS pseudo-element name to use for the fallback test.
+    /// May be used in conjunction with <see cref="FallbackTestClass"/> and <see cref="FallbackTestValue"/>,
+    /// and either <see cref="FallbackHref"/> or <see cref="FallbackHrefInclude"/>.
+    /// </summary>
+    [HtmlAttributeName(FallbackTestPseudoElementAttributeName)]
+    public string FallbackTestPseudoElement { get; set; }
+
     /// <summary>
     /// The CSS property value to use for the fallback test.
     /// Must be used in conjunction with <see cref="FallbackTestClass"/> and <see cref="FallbackTestProperty"/>,
@@ -358,9 +370,12 @@ private void BuildFallbackBlock(TagHelperAttributeList attributes, TagHelperCont
         // <link /> tag to load the fallback stylesheet if the test CSS property value is found to be false,
         // indicating that the primary stylesheet failed to load.
         // GetEmbeddedJavaScript returns JavaScript to which we add '"{0}","{1}",{2});'
+        // or '"{0}","{1}",{2},{3});' depending an optional pseudo-element parameter.
+        var usePseudoElement = FallbackTestPseudoElement != null;
         builder
             .AppendHtml("<script>")
-            .AppendHtml(JavaScriptResources.GetEmbeddedJavaScript(FallbackJavaScriptResourceName))
+            .AppendHtml(JavaScriptResources.GetEmbeddedJavaScript(usePseudoElement ?
+                FallbackWithPseudoJavaScriptResourceName : FallbackJavaScriptResourceName))
             .AppendHtml("\"")
             .AppendHtml(JavaScriptEncoder.Encode(FallbackTestProperty))
             .AppendHtml("\",\"")
@@ -395,8 +410,15 @@ private void BuildFallbackBlock(TagHelperAttributeList attributes, TagHelperCont
         stringBuilder.Clear();
         var encodedScriptTags = JavaScriptEncoder.Encode(scriptTags);
         builder.AppendHtml(encodedScriptTags);
-
-        builder.AppendHtml("\");</script>");
+        builder.AppendHtml("\"");
+        if (usePseudoElement)
+        {
+            builder
+                .AppendHtml(", \"")
+                .AppendHtml(JavaScriptEncoder.Encode(FallbackTestPseudoElement))
+                .AppendHtml("\"");
+        }
+        builder.AppendHtml(");</script>");
     }
 
     private bool HasStyleSheetLinkType(TagHelperAttributeList attributes)
diff --git a/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt b/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt
index 3b900f5c4f03..dc241f896473 100644
--- a/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt
+++ b/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt
@@ -1,3 +1,5 @@
 #nullable enable
 ~Microsoft.AspNetCore.Mvc.TagHelpers.InputTagHelper.FormName.get -> string
 ~Microsoft.AspNetCore.Mvc.TagHelpers.InputTagHelper.FormName.set -> void
+~Microsoft.AspNetCore.Mvc.TagHelpers.LinkTagHelper.FallbackTestPseudoElement.get -> string
+~Microsoft.AspNetCore.Mvc.TagHelpers.LinkTagHelper.FallbackTestPseudoElement.set -> void
diff --git a/src/Mvc/Mvc.TagHelpers/src/compiler/resources/LinkTagHelper_FallbackWithPseudoJavaScript.js b/src/Mvc/Mvc.TagHelpers/src/compiler/resources/LinkTagHelper_FallbackWithPseudoJavaScript.js
new file mode 100644
index 000000000000..e987f3a1e991
--- /dev/null
+++ b/src/Mvc/Mvc.TagHelpers/src/compiler/resources/LinkTagHelper_FallbackWithPseudoJavaScript.js
@@ -0,0 +1 @@
+!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}();
\ No newline at end of file
diff --git a/src/Mvc/Mvc.TagHelpers/test/LinkTagHelperTest.cs b/src/Mvc/Mvc.TagHelpers/test/LinkTagHelperTest.cs
index 9126be503d75..9539c0ac5e81 100644
--- a/src/Mvc/Mvc.TagHelpers/test/LinkTagHelperTest.cs
+++ b/src/Mvc/Mvc.TagHelpers/test/LinkTagHelperTest.cs
@@ -285,6 +285,130 @@ public static TheoryData RunsWhenRequiredAttributesArePresent_Data
                             tagHelper.SuppressFallbackIntegrity = false;
                         }
                     },
+                    // asp-fallback-test-pseudo-element Attribute is present
+                    {
+                        new TagHelperAttributeList
+                        {
+                            new TagHelperAttribute("asp-fallback-href", "test.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden")
+                        },
+                        tagHelper =>
+                        {
+                            tagHelper.FallbackHref = "test.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                        }
+                    },
+                    {
+                        new TagHelperAttributeList
+                        {
+                            new TagHelperAttribute("asp-fallback-href-include", "*.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden")
+                        },
+                        tagHelper =>
+                        {
+                            tagHelper.FallbackHrefInclude = "*.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                        }
+                    },
+                    // File Version
+                    {
+                        new TagHelperAttributeList
+                        {
+                            new TagHelperAttribute("asp-fallback-href", "test.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden"),
+                            new TagHelperAttribute("asp-append-version", "true")
+                        },
+                        tagHelper =>
+                        {
+                            tagHelper.FallbackHref = "test.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                            tagHelper.AppendVersion = true;
+                        }
+                    },
+                    {
+                        new TagHelperAttributeList
+                        {
+                            new TagHelperAttribute("asp-fallback-href-include", "*.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden"),
+                            new TagHelperAttribute("asp-append-version", "true")
+                        },
+                        tagHelper =>
+                        {
+                            tagHelper.FallbackHrefInclude = "*.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                            tagHelper.AppendVersion = true;
+                        }
+                    },
+                    // asp-suppress-fallback-integrity Attribute true
+                    {
+                        new TagHelperAttributeList
+                        {
+                            new TagHelperAttribute("asp-fallback-href", "test.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden"),
+                            new TagHelperAttribute("asp-append-version", "true"),
+                            new TagHelperAttribute("asp-suppress-fallback-integrity", "true")
+                        },
+                        tagHelper =>
+                        {
+                            tagHelper.FallbackHref = "test.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                            tagHelper.AppendVersion = true;
+                            tagHelper.SuppressFallbackIntegrity = true;
+                        }
+                    },
+                    // asp-suppress-fallback-integrity Attribute false
+                    {
+                        new TagHelperAttributeList
+                        {
+                            new TagHelperAttribute("asp-fallback-href", "test.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden"),
+                            new TagHelperAttribute("asp-append-version", "true"),
+                            new TagHelperAttribute("asp-suppress-fallback-integrity", "false")
+                        },
+                        tagHelper =>
+                        {
+                            tagHelper.FallbackHref = "test.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                            tagHelper.AppendVersion = true;
+                            tagHelper.SuppressFallbackIntegrity = false;
+                        }
+                    },
                 };
         }
     }
@@ -420,6 +544,7 @@ public void PreservesOrderOfNonHrefAttributes()
                     { "asp-fallback-href", "test.css" },
                     { "asp-fallback-test-class", "hidden" },
                     { "asp-fallback-test-property", "visibility" },
+                    { "asp-fallback-test-pseudo-element", "before" },
                     { "asp-fallback-test-value", "hidden" },
             });
         var output = MakeTagHelperOutput("link",
@@ -433,6 +558,7 @@ public void PreservesOrderOfNonHrefAttributes()
         helper.FallbackHref = "test.css";
         helper.FallbackTestClass = "hidden";
         helper.FallbackTestProperty = "visibility";
+        helper.FallbackTestPseudoElement = "before";
         helper.FallbackTestValue = "hidden";
         helper.Href = "test.css";
 
@@ -515,6 +641,64 @@ public static TheoryData DoesNotRunWhenARequiredAttributeIsMissing_Data
                             tagHelper.FallbackTestProperty = "visibility";
                             tagHelper.FallbackTestValue = "hidden";
                         }
+                    },
+                    {
+                        new TagHelperAttributeList
+                        {
+                            // This is commented out on purpose: new TagHelperAttribute("asp-fallback-href", "test.css"),
+                            // Note asp-href-include attribute isn't included.
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden")
+                        },
+                        tagHelper =>
+                        {
+                            // This is commented out on purpose: tagHelper.FallbackHref = "test.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                        }
+                    },
+                    {
+                        new TagHelperAttributeList
+                        {
+                            new TagHelperAttribute("asp-fallback-href", "test.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            // This is commented out on purpose: new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            // Note asp-href-include attribute isn't included.
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden")
+                        },
+                        tagHelper =>
+                        {
+                            tagHelper.FallbackHref = "test.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            // This is commented out on purpose: tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                        }
+                    },
+                    {
+                        new TagHelperAttributeList
+                        {
+                            // This is commented out on purpose: new TagHelperAttribute("asp-fallback-href-include", "test.css"),
+                            new TagHelperAttribute("asp-fallback-href-exclude", "**/*.min.css"),
+                            new TagHelperAttribute("asp-fallback-test-class", "hidden"),
+                            new TagHelperAttribute("asp-fallback-test-property", "visibility"),
+                            new TagHelperAttribute("asp-fallback-test-pseudo-element", "before"),
+                            new TagHelperAttribute("asp-fallback-test-value", "hidden")
+                        },
+                        tagHelper =>
+                        {
+                            // This is commented out on purpose: tagHelper.FallbackHrefInclude = "test.css";
+                            tagHelper.FallbackHrefExclude = "**/*.min.css";
+                            tagHelper.FallbackTestClass = "hidden";
+                            tagHelper.FallbackTestProperty = "visibility";
+                            tagHelper.FallbackTestPseudoElement = "before";
+                            tagHelper.FallbackTestValue = "hidden";
+                        }
                     }
                 };
         }
@@ -880,6 +1064,135 @@ public void RenderLinkTags_FallbackHref_WithFileVersion_EncodesAsExpected()
         Assert.Equal(expectedContent, content);
     }
 
+    [Fact]
+    public void RenderLinkTags_FallbackHref_WithFileVersionAndPseudoElement()
+    {
+        // Arrange
+        var expectedPostElement = Environment.NewLine +
+            "<meta name=\"x-stylesheet-fallback-test\" content=\"\" class=\"hidden\" /><script>!function" +
+            "(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName(\"SCRIPT\"),h=g[g.length-1]." +
+            "previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView." +
+            "getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link " +
+            "href=\"'+c[e]+'\" '+d+\"/>\")}(\"JavaScriptEncode[[visibility]]\",\"JavaScriptEncode[[hidden]]\"" +
+            ",[\"JavaScriptEncode[[HtmlEncode[[/fallback.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]]]\"]," +
+            " \"JavaScriptEncode[[rel=\"stylesheet\" ]]\", \"JavaScriptEncode[[before]]\");</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-pseudo-element", "before" },
+                    { "asp-fallback-test-value", "hidden" },
+                    { "href", "/css/site.css" },
+                    { "rel", new HtmlString("stylesheet") },
+            });
+        var output = MakeTagHelperOutput(
+            "link",
+            attributes: new TagHelperAttributeList
+            {
+                    { "rel", new HtmlString("stylesheet") },
+            });
+        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 = GetHelper();
+        helper.AppendVersion = true;
+        helper.Href = "/css/site.css";
+        helper.FallbackHrefInclude = "**/fallback.css";
+        helper.FallbackTestClass = "hidden";
+        helper.FallbackTestProperty = "visibility";
+        helper.FallbackTestPseudoElement = "before";
+        helper.FallbackTestValue = "hidden";
+        helper.GlobbingUrlBuilder = globbingUrlBuilder.Object;
+
+        // 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_WithFileVersionAndPseudoElement_EncodesAsExpected()
+    {
+        // Arrange
+        var expectedContent = "<link encoded=\"contains \"quotes\"\" " +
+            "href=\"HtmlEncode[[/css/site.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]\" " +
+            "literal=\"HtmlEncode[[all HTML encoded]]\" " +
+            "mixed=\"HtmlEncode[[HTML encoded]] and contains \"quotes\"\" rel=\"stylesheet\" />" +
+            Environment.NewLine +
+            "<meta name=\"x-stylesheet-fallback-test\" content=\"\" class=\"HtmlEncode[[hidden]]\" /><script>" +
+            "!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName(\"SCRIPT\"),h=g[g.length-1]." +
+            "previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView." +
+            "getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link " +
+            "href=\"'+c[e]+'\" '+d+\"/>\")}(\"JavaScriptEncode[[visibility]]\",\"JavaScriptEncode[[hidden]]\"," +
+            "[\"JavaScriptEncode[[HtmlEncode[[/fallback.css?v=f4OxZX_x_FO5LcGBSKHWXfwtSx-j1ncoSt3SABJtkGk]]]]\"], " +
+            "\"JavaScriptEncode[[encoded=\"contains \"quotes\"\" literal=\"HtmlEncode[[all HTML encoded]]\" " +
+            "mixed=\"HtmlEncode[[HTML encoded]] and contains \"quotes\"\" rel=\"stylesheet\" ]]\", \"JavaScriptEncode[[before]]\");" +
+            "</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-pseudo-element", "before" },
+                    { "asp-fallback-test-value", "hidden" },
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "href", "/css/site.css" },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                    { "rel", new HtmlString("stylesheet") },
+            });
+        var output = MakeTagHelperOutput(
+            "link",
+            attributes: new TagHelperAttributeList
+            {
+                    { "encoded", new HtmlString("contains \"quotes\"") },
+                    { "literal", "all HTML encoded" },
+                    { "mixed", mixed },
+                    { "rel", new HtmlString("stylesheet") },
+            });
+        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 = GetHelper();
+
+        helper.AppendVersion = true;
+        helper.FallbackHrefInclude = "**/fallback.css";
+        helper.FallbackTestClass = "hidden";
+        helper.FallbackTestProperty = "visibility";
+        helper.FallbackTestPseudoElement = "before";
+        helper.FallbackTestValue = "hidden";
+        helper.GlobbingUrlBuilder = globbingUrlBuilder.Object;
+        helper.Href = "/css/site.css";
+
+        // 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()
     {
diff --git a/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html b/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
index 00ae75a1c44b..a386cea5945e 100644
--- a/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
+++ b/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
@@ -140,6 +140,81 @@
     <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,d){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]");</script>
 
+    <!-- Fallback to static href, with pseudo-element -->
+    <link href="HtmlEncode[[/styles/site.min.css?a=b&c=d]]" rel="stylesheet" data-extra="test" title='"the" title' />
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css?a=b&c=d]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" title='"the" title' ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static href with pseudo-element and no asp-suppress-fallback-integrity attribute, default behavior is to keep integrity hash -->
+    <link href="HtmlEncode[[/styles/site.min.css?a=b&c=d]]" rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" />
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css?a=b&c=d]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static href with pseudo-element, and asp-suppress-fallback-integrity set to false, behavior is to keep integrity hash -->
+    <link href="HtmlEncode[[/styles/site.min.css?a=b&c=d]]" rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" />
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css?a=b&c=d]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static href with asp-suppress-fallback-integrity provided, with pseudo-element; removes integrity attribute on fallback so that different CSS can be loaded  -->
+    <link href="HtmlEncode[[/styles/site.min.css?a=b&c=d]]" rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" />
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/siteIntegrity.css?a=b&c=d]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" title='"the" title' crossorigin="anonymous" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static href with dynamic attributes, with pseudo-element -->
+    <link href="HtmlEncode[[/styles/site.min.css?a=b&c=d]]" rel="HtmlEncode[[stylesheet]]" data-extra="HtmlEncode[[test]]" title='HtmlEncode[["the" title]]' />
+
+    <!-- Fallback from globbed href to static href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback from globbed href with exclude to static href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback from globbed and static href to static href, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback from globbed and static href with exclude to static href, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static href with no primary href, with pseudo-element -->
+    <link rel="stylesheet" data-extra="test">
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to globbed href, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static and globbed href, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]","JavaScriptEncode[[HtmlEncode[[/styles/sub/site2.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static and globbed href should dedupe, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback to static and globbed href with exclude, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]","JavaScriptEncode[[HtmlEncode[[/styles/siteIntegrity.css]]]]","JavaScriptEncode[[HtmlEncode[[/styles/sub/site2.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback from globbed href to globbed href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback from globbed href with exclude to globbed href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="HtmlEncode[[hidden]]" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback from globbed and static href to globbed href, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback from globbed and static href with exclude to globbed href, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</script>
+
+    <!-- Fallback with file version, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("JavaScriptEncode[[visibility]]","JavaScriptEncode[[hidden]]",["JavaScriptEncode[[HtmlEncode[[/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]]]"], "JavaScriptEncode[[rel="stylesheet" data-extra="test" ]]", "JavaScriptEncode[[:before]]");</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/siteIntegrity.css?v=2PJDxTb5ea6QWpW5p3vvrvP3bat7l18amFI0M8-xBls]]" 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" />
 </head>
diff --git a/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html b/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
index eeff44b25541..7cf0056a85e9 100644
--- a/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
+++ b/src/Mvc/test/Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
@@ -141,6 +141,82 @@
     <link href="/styles/site.min.css" rel="stylesheet" data-extra="test">
 <meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ");</script>
 
+    <!-- Fallback to static href, with pseudo-element -->
+    <link href="/styles/site.min.css?a=b&amp;c=d" rel="stylesheet" data-extra="test" title='"the" title' />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css?a=b\u0026amp;c=d"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 title=\u0027\u0022the\u0022 title\u0027 ", ":before");</script>
+
+    <!-- Fallback to static href with pseudo-element and no asp-suppress-fallback-integrity attribute, default behavior is to keep integrity hash -->
+    <link href="/styles/site.min.css?a=b&amp;c=d" rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css?a=b\u0026amp;c=d"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 title=\u0027\u0022the\u0022 title\u0027 integrity=\u0022XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh\u002BpQc=\u0022 crossorigin=\u0022anonymous\u0022 ", ":before");</script>
+
+    <!-- Fallback to static href with pseudo-element, and asp-suppress-fallback-integrity set to false, behavior is to keep integrity hash -->
+    <link href="/styles/site.min.css?a=b&amp;c=d" rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css?a=b\u0026amp;c=d"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 title=\u0027\u0022the\u0022 title\u0027 integrity=\u0022XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh\u002BpQc=\u0022 crossorigin=\u0022anonymous\u0022 ", ":before");</script>
+
+    <!-- Fallback to static href with asp-suppress-fallback-integrity provided, with pseudo-element; removes integrity attribute on fallback so that different CSS can be loaded  -->
+    <link href="/styles/site.min.css?a=b&amp;c=d" rel="stylesheet" data-extra="test" title='"the" title' integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc=" crossorigin="anonymous" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/siteIntegrity.css?a=b\u0026amp;c=d"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 title=\u0027\u0022the\u0022 title\u0027 crossorigin=\u0022anonymous\u0022 ", ":before");</script>
+
+    <!-- Fallback to static href with dynamic attributes, with pseudo-element -->
+    <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,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css?a=b\u0026amp;c=d"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 title=\u0027\u0026quot;the\u0026quot; title\u0027 ", ":before");</script>
+
+    <!-- Fallback from globbed href to static href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback from globbed href with exclude to static href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback from globbed and static href to static href, with pseudo-element -->
+    <link href="styles/site.min.css" rel="stylesheet" data-extra="test" /><link href="/styles/site.css" rel="stylesheet" data-extra="test" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback from globbed and static href with exclude to static href, with pseudo-element -->
+    <link href="styles/site.min.css" rel="stylesheet" data-extra="test" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback to static href with no primary href, with pseudo-element -->
+    <link rel="stylesheet" data-extra="test">
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback to globbed href, with pseudo-element -->
+    <link href="/styles/site.min.css" rel="stylesheet" data-extra="test" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback to static and globbed href, with pseudo-element -->
+    <link href="/styles/site.min.css" rel="stylesheet" data-extra="test" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css","/styles/sub/site2.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback to static and globbed href should dedupe, with pseudo-element -->
+    <link href="/styles/site.min.css" rel="stylesheet" data-extra="test" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback to static and globbed href with exclude, with pseudo-element -->
+    <link href="/styles/site.min.css" rel="stylesheet" data-extra="test" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css","/styles/siteIntegrity.css","/styles/sub/site2.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback from globbed href to globbed href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback from globbed href with exclude to globbed href, with pseudo-element -->
+    
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback from globbed and static href to globbed href, with pseudo-element -->
+    <link href="styles/site.min.css" rel="stylesheet" data-extra="test" /><link href="/styles/site.css" rel="stylesheet" data-extra="test" />
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback from globbed and static href with exclude to globbed href, with pseudo-element -->
+    <link href="styles/site.min.css" rel="stylesheet" data-extra="test">
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
+    <!-- Fallback with file version, with pseudo-element -->
+    <link href="/styles/site.min.css" rel="stylesheet" data-extra="test">
+<meta name="x-stylesheet-fallback-test" content="" class="hidden" /><script>!function(a,b,c,d,j){var e,f=document,g=f.getElementsByTagName("SCRIPT"),h=g[g.length-1].previousElementSibling,i=f.defaultView&&f.defaultView.getComputedStyle?f.defaultView.getComputedStyle(h,j):h.currentStyle;if(i&&i[a]!==b)for(e=0;e<c.length;e++)f.write('<link href="'+c[e]+'" '+d+"/>")}("visibility","hidden",["/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc"], "rel=\u0022stylesheet\u0022 data-extra=\u0022test\u0022 ", ":before");</script>
+
     <!-- Globbed link tag with existing file, static href and file version -->
     <link href="/styles/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc" rel="stylesheet" /><link href="/styles/siteIntegrity.css?v=2PJDxTb5ea6QWpW5p3vvrvP3bat7l18amFI0M8-xBls" rel="stylesheet" /><link href="/styles/sub/site2.css?v=30cxPex0tA9xEatW7f1Qhnn8tVLAHgE6xwIZhESq0y0" rel="stylesheet" /><link href="/styles/sub/site3.css?v=fSxxOr1Q4Dq2uPuzlju5UYGuK0SKABI-ghvaIGEsZDc" rel="stylesheet" /><link href="/styles/sub/site3.min.css?v=s8JMmAZxBn0dzuhRtQ0wgOvNBK4XRJRWEC2wfzsVF9M" rel="stylesheet" />
 </head>
diff --git a/src/Mvc/test/WebSites/HtmlGenerationWebSite/Views/HtmlGeneration_Home/Link.cshtml b/src/Mvc/test/WebSites/HtmlGenerationWebSite/Views/HtmlGeneration_Home/Link.cshtml
index 9bc535fd5f10..c84ac48fc83f 100644
--- a/src/Mvc/test/WebSites/HtmlGenerationWebSite/Views/HtmlGeneration_Home/Link.cshtml
+++ b/src/Mvc/test/WebSites/HtmlGenerationWebSite/Views/HtmlGeneration_Home/Link.cshtml
@@ -242,6 +242,173 @@
           asp-fallback-test-value="hidden"
           asp-append-version="true">
 
+    <!-- Fallback to static href, with pseudo-element -->
+    <link href="~/styles/site.min.css?a=b&c=d" rel="stylesheet" data-extra="test" title='"the" title'
+          asp-fallback-href="~/styles/site.css?a=b&c=d"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback to static href with pseudo-element and no asp-suppress-fallback-integrity attribute, default behavior is to keep integrity hash -->
+    <link href="~/styles/site.min.css?a=b&c=d" rel="stylesheet" data-extra="test" title='"the" title'
+          integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc="
+          crossorigin="anonymous"
+          asp-fallback-href="~/styles/site.css?a=b&c=d"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback to static href with pseudo-element, and asp-suppress-fallback-integrity set to false, behavior is to keep integrity hash -->
+    <link href="~/styles/site.min.css?a=b&c=d" rel="stylesheet" data-extra="test" title='"the" title'
+          integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc="
+          crossorigin="anonymous"
+          asp-fallback-href="~/styles/site.css?a=b&c=d"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden"
+          asp-suppress-fallback-integrity="false" />
+
+    <!-- Fallback to static href with asp-suppress-fallback-integrity provided, with pseudo-element; removes integrity attribute on fallback so that different CSS can be loaded  -->
+    <link href="~/styles/site.min.css?a=b&c=d" rel="stylesheet" data-extra="test" title='"the" title'
+          integrity="XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh+pQc="
+          crossorigin="anonymous"
+          asp-fallback-href="~/styles/siteIntegrity.css?a=b&c=d"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden"
+          asp-suppress-fallback-integrity />
+
+    <!-- Fallback to static href with dynamic attributes, with pseudo-element -->
+    <link href="~/styles/site.min.css?a=b&c=d" rel="@("stylesheet")" data-extra="@("test")" title='@(@"""the"" title")'
+          asp-fallback-href="~/styles/site.css?a=b&c=d"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback from globbed href to static href, with pseudo-element -->
+    <link asp-href-include="styles/site.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback from globbed href with exclude to static href, with pseudo-element -->
+    <link asp-href-include="**/*.min.css" asp-href-exclude=" **/site3.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden">
+
+    <!-- Fallback from globbed and static href to static href, with pseudo-element -->
+    <link href="styles/site.min.css" asp-href-include="styles/site.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback from globbed and static href with exclude to static href, with pseudo-element -->
+    <link href="styles/site.min.css" asp-href-include="**/*.min.css" asp-href-exclude="**/site3.min.css"
+          rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback to static href with no primary href, with pseudo-element -->
+    <link rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-value="hidden"
+          asp-fallback-test-pseudo-element=":before">
+
+    <!-- Fallback to globbed href, with pseudo-element -->
+    <link href="~/styles/site.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href-include="**/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback to static and globbed href, with pseudo-element -->
+    <link href="~/styles/site.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-href-include="**/site2.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback to static and globbed href should dedupe, with pseudo-element -->
+    <link href="~/styles/site.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-href-include="**/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback to static and globbed href with exclude, with pseudo-element -->
+    <link href="~/styles/site.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-href-include="**/styles/**/*.css"
+          asp-fallback-href-exclude="**/site3*.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback from globbed href to globbed href, with pseudo-element -->
+    <link asp-href-include="styles/site.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href-include="**/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback from globbed href with exclude to globbed href, with pseudo-element -->
+    <link asp-href-include="**/*.min.css" asp-href-exclude="**/site3.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href-include="**/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback from globbed and static href to globbed href, with pseudo-element -->
+    <link href="styles/site.min.css" asp-href-include="styles/site.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href-include="**/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden" />
+
+    <!-- Fallback from globbed and static href with exclude to globbed href, with pseudo-element -->
+    <link href="styles/site.min.css" asp-href-include="**/*.min.css" asp-href-exclude="**/site3.min.css"
+          rel="stylesheet" data-extra="test"
+          asp-fallback-href-include="**/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden">
+
+    <!-- Fallback with file version, with pseudo-element -->
+    <link href="~/styles/site.min.css" rel="stylesheet" data-extra="test"
+          asp-fallback-href="~/styles/site.css"
+          asp-fallback-test-class="hidden"
+          asp-fallback-test-property="visibility"
+          asp-fallback-test-pseudo-element=":before"
+          asp-fallback-test-value="hidden"
+          asp-append-version="true">
+
     <!-- Globbed link tag with existing file, static href and file version -->
     <link href="~/styles/site.css" asp-href-include="**/styles/**/*.css" rel="stylesheet" asp-append-version="true" />
 </head>

From 30216b13e541d1c20f570a917ebf5997a739cb9d Mon Sep 17 00:00:00 2001
From: Sergey Kalinichenko <dasblinkenlight@outlook.com>
Date: Tue, 17 Oct 2023 22:19:14 -0400
Subject: [PATCH 2/4] Added non-minified version of the fallback script

---
 ...kTagHelper_FallbackWithPseudoJavaScript.js | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js

diff --git a/src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js b/src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js
new file mode 100644
index 000000000000..c27f3eb91bb2
--- /dev/null
+++ b/src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js
@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+(
+ /**
+  * This function finds the previous element (assumed to be meta) and tests its current CSS style using the passed
+  * values and pseudo-element, to determine if a stylesheet was loaded. If not, this function loads
+  * the fallback stylesheet via document.write.
+  *
+  * @param {string} cssTestPropertyName - The name of the CSS property to test.
+  * @param {string} cssTestPropertyValue - The value to test the specified CSS property for.
+  * @param {string[]} fallbackHrefs - The URLs to the stylesheets to load in the case the test fails.
+  * @param {string} extraAttributes - The extra attributes string that should be included on the generated link tags.
+  * @param {string} pseudoElement - A string specifying the pseudo-element to match.
+  */
+ function loadFallbackStylesheet(cssTestPropertyName, cssTestPropertyValue, fallbackHrefs, extraAttributes) {
+    var doc = document,
+        // Find the last script tag on the page which will be this one, as JS executes as it loads
+        scriptElements = doc.getElementsByTagName("SCRIPT"),
+        // Find the meta tag before this script tag, that's the element we're going to test the CSS property on
+        meta = scriptElements[scriptElements.length - 1].previousElementSibling,
+        // Get the current style of the meta tag starting with standards-based API and falling back to <=IE8 API
+        metaStyle = (doc.defaultView && doc.defaultView.getComputedStyle) ?
+            doc.defaultView.getComputedStyle(meta, pseudoElement) : meta.currentStyle,
+        i;
+
+    if (metaStyle && metaStyle[cssTestPropertyName] !== cssTestPropertyValue) {
+        for (i = 0; i < fallbackHrefs.length; i++) {
+            doc.write('<link href="' + fallbackHrefs[i] + '" ' + extraAttributes + '/>');
+        }
+    }
+})();

From c9d598ccca31119a6967ed49088778c97c75d99d Mon Sep 17 00:00:00 2001
From: Sergey Kalinichenko <dasblinkenlight@outlook.com>
Date: Mon, 20 Nov 2023 22:18:30 -0500
Subject: [PATCH 3/4] Updated PublicAPI.Unshipped

---
 src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt b/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt
index 7dc5c58110bf..b7054afd9c5d 100644
--- a/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt
+++ b/src/Mvc/Mvc.TagHelpers/src/PublicAPI.Unshipped.txt
@@ -1 +1,3 @@
 #nullable enable
+~Microsoft.AspNetCore.Mvc.TagHelpers.LinkTagHelper.FallbackTestPseudoElement.get -> string
+~Microsoft.AspNetCore.Mvc.TagHelpers.LinkTagHelper.FallbackTestPseudoElement.set -> void

From 336db710cd33aaf023220450e08fd83ccc4dfa94 Mon Sep 17 00:00:00 2001
From: Sergey Kalinichenko <dasblinkenlight@outlook.com>
Date: Fri, 15 Dec 2023 20:27:52 -0500
Subject: [PATCH 4/4] Fixed the non-minified javascript file

(added a missing parameter and fixed its comment)
---
 .../src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js      | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js b/src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js
index c27f3eb91bb2..1e68a667897f 100644
--- a/src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js
+++ b/src/Mvc/Mvc.TagHelpers/src/js/LinkTagHelper_FallbackWithPseudoJavaScript.js
@@ -10,9 +10,9 @@
   * @param {string} cssTestPropertyValue - The value to test the specified CSS property for.
   * @param {string[]} fallbackHrefs - The URLs to the stylesheets to load in the case the test fails.
   * @param {string} extraAttributes - The extra attributes string that should be included on the generated link tags.
-  * @param {string} pseudoElement - A string specifying the pseudo-element to match.
+  * @param {string} pseudoElement - An optional string specifying the CSS pseudo-element to match.
   */
- function loadFallbackStylesheet(cssTestPropertyName, cssTestPropertyValue, fallbackHrefs, extraAttributes) {
+ function loadFallbackStylesheet(cssTestPropertyName, cssTestPropertyValue, fallbackHrefs, extraAttributes, pseudoElement) {
     var doc = document,
         // Find the last script tag on the page which will be this one, as JS executes as it loads
         scriptElements = doc.getElementsByTagName("SCRIPT"),