From f1eefdb650c5f7bd07ccc4499867ccaaf6dc6382 Mon Sep 17 00:00:00 2001
From: "N. Taylor Mullen" <nimullen@microsoft.com>
Date: Mon, 17 Aug 2015 16:56:58 -0700
Subject: [PATCH] Enable `CopyHtmlAttribute` to maintain copied attribute
 order.

- Updated implementation to do a best guess at copying an attribute back into `TagHelperOutput.Attributes`.
- Updated existing functional and unit tests to account for maintained attribute order.
- Added a set of complex order based unit tests to validate `CopyHtmlAttribute` properly maintains order.

#2639
---
 .../TagHelperOutputExtensions.cs              |  95 ++++-
 ...WebSite.HtmlGeneration_Customer.Index.html |   4 +-
 ...e.HtmlGeneration_Home.CreateWarehouse.html |   2 +-
 ...nWebSite.HtmlGeneration_Home.Customer.html |   4 +-
 ...Site.HtmlGeneration_Home.EmployeeList.html |   6 +-
 ...tionWebSite.HtmlGeneration_Home.Image.html |   2 +-
 ...Site.HtmlGeneration_Home.Link.Encoded.html |  42 +--
 ...ationWebSite.HtmlGeneration_Home.Link.html |  42 +--
 ...ite.HtmlGeneration_Home.Order.Encoded.html |   8 +-
 ...tionWebSite.HtmlGeneration_Home.Order.html |   8 +-
 ...e.HtmlGeneration_Home.Product.Encoded.html |   4 +-
 ...onWebSite.HtmlGeneration_Home.Product.html |   4 +-
 ...bSite.HtmlGeneration_Home.ProductList.html |   8 +-
 ...te.HtmlGeneration_Home.Script.Encoded.html |   8 +-
 ...ionWebSite.HtmlGeneration_Home.Script.html |   8 +-
 .../InputTagHelperTest.cs                     |   2 +-
 .../LinkTagHelperTest.cs                      |   4 +-
 .../ScriptTagHelperTest.cs                    |   4 +-
 .../TagHelperOutputExtensionsTest.cs          | 334 +++++++++++++++++-
 19 files changed, 497 insertions(+), 92 deletions(-)

diff --git a/src/Microsoft.AspNet.Mvc.TagHelpers/TagHelperOutputExtensions.cs b/src/Microsoft.AspNet.Mvc.TagHelpers/TagHelperOutputExtensions.cs
index be7410a15c..cb738ba070 100644
--- a/src/Microsoft.AspNet.Mvc.TagHelpers/TagHelperOutputExtensions.cs
+++ b/src/Microsoft.AspNet.Mvc.TagHelpers/TagHelperOutputExtensions.cs
@@ -23,9 +23,17 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
         /// <param name="tagHelperOutput">The <see cref="TagHelperOutput"/> this method extends.</param>
         /// <param name="attributeName">The name of the bound attribute.</param>
         /// <param name="context">The <see cref="TagHelperContext"/>.</param>
-        /// <remarks>Only copies the attribute if <paramref name="tagHelperOutput"/>'s
+        /// <remarks>
+        /// <para>
+        /// Only copies the attribute if <paramref name="tagHelperOutput"/>'s
         /// <see cref="TagHelperOutput.Attributes"/> does not contain an attribute with the given
-        /// <paramref name="attributeName"/>.</remarks>
+        /// <paramref name="attributeName"/>.
+        /// </para>
+        /// <para>
+        /// Duplicate attributes same name in <paramref name="context"/>'s <see cref="TagHelperContext.AllAttributes"/>
+        /// or <paramref name="tagHelperOutput"/>'s <see cref="TagHelperOutput.Attributes"/> may result in copied
+        /// attribute order not being maintained.
+        /// </para></remarks>
         public static void CopyHtmlAttribute(
             [NotNull] this TagHelperOutput tagHelperOutput,
             [NotNull] string attributeName,
@@ -33,21 +41,30 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
         {
             if (!tagHelperOutput.Attributes.ContainsName(attributeName))
             {
-                IEnumerable<IReadOnlyTagHelperAttribute> entries;
+                var copiedAttribute = false;
 
-                // We look for the original attribute so we can restore the exact attribute name the user typed.
-                // Approach also ignores changes made to tagHelperOutput[attributeName].
-                if (!context.AllAttributes.TryGetAttributes(attributeName, out entries))
+                // We iterate context.AllAttributes backwards since we prioritize TagHelperOutput values occurring
+                // before the current context.AllAttribtes[i].
+                for (var i = context.AllAttributes.Count - 1; i >= 0; i--)
+                {
+                    // We look for the original attribute so we can restore the exact attribute name the user typed in
+                    // approximately the same position where the user wrote it in the Razor source.
+                    if (string.Equals(
+                        attributeName,
+                        context.AllAttributes[i].Name,
+                        StringComparison.OrdinalIgnoreCase))
+                    {
+                        CopyHtmlAttribute(i, tagHelperOutput, context);
+                        copiedAttribute = true;
+                    }
+                }
+
+                if (!copiedAttribute)
                 {
                     throw new ArgumentException(
                         Resources.FormatTagHelperOutput_AttributeDoesNotExist(attributeName, nameof(TagHelperContext)),
                         nameof(attributeName));
                 }
-
-                foreach (var entry in entries)
-                {
-                    tagHelperOutput.Attributes.Add(entry.Name, entry.Value);
-                }
             }
         }
 
@@ -100,5 +117,61 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
                 tagHelperOutput.Attributes.Remove(attribute);
             }
         }
+
+        private static void CopyHtmlAttribute(
+            int allAttributeIndex,
+            TagHelperOutput tagHelperOutput,
+            TagHelperContext context)
+        {
+            var existingAttribute = context.AllAttributes[allAttributeIndex];
+            var copiedAttribute = new TagHelperAttribute
+            {
+                Name = existingAttribute.Name,
+                Value = existingAttribute.Value,
+                Minimized = existingAttribute.Minimized
+            };
+
+            // Move backwards through context.AllAttributes from the provided index until we find a familiar attribute
+            // in tagHelperOutput where we can insert the copied value after the familiar one.
+            for (var i = allAttributeIndex - 1; i >= 0; i--)
+            {
+                var previousName = context.AllAttributes[i].Name;
+                var index = IndexOfFirstMatch(previousName, tagHelperOutput.Attributes);
+                if (index != -1)
+                {
+                    tagHelperOutput.Attributes.Insert(index + 1, copiedAttribute);
+                    return;
+                }
+            }
+
+            // Move forward through context.AllAttributes from the provided index until we find a familiar attribute in
+            // tagHelperOutput where we can insert the copied value.
+            for (var i = allAttributeIndex + 1; i < context.AllAttributes.Count; i++)
+            {
+                var nextName = context.AllAttributes[i].Name;
+                var index = IndexOfFirstMatch(nextName, tagHelperOutput.Attributes);
+                if (index != -1)
+                {
+                    tagHelperOutput.Attributes.Insert(index, copiedAttribute);
+                    return;
+                }
+            }
+
+            // Couldn't determine the attribute's location, add it to the end.
+            tagHelperOutput.Attributes.Add(copiedAttribute);
+        }
+
+        private static int IndexOfFirstMatch(string name, TagHelperAttributeList attributes)
+        {
+            for (var i = 0; i < attributes.Count; i++)
+            {
+                if (string.Equals(name, attributes[i].Name, StringComparison.OrdinalIgnoreCase))
+                {
+                    return i;
+                }
+            }
+
+            return -1;
+        }
     }
 }
\ No newline at end of file
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Customer.Index.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Customer.Index.html
index 7d6cf27c87..9026b3bc0d 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Customer.Index.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Customer.Index.html
@@ -3,7 +3,7 @@
     <form action="/Customer/HtmlGeneration_Customer" method="post">
         <div>
             <label class="order" for="Number">Number</label>
-            <input class="form-control input-validation-error" type="number" data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." id="Number" name="Number" value="" />
+            <input type="number" class="form-control input-validation-error" data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." id="Number" name="Number" value="" />
             <span class="field-validation-error" data-valmsg-for="Number" data-valmsg-replace="true">The value &#x27;&#x27; is invalid.</span>
         </div>
         <div>
@@ -21,7 +21,7 @@
         </div>
         <div>
             <label class="order" for="Password">Password</label>
-            <input class="form-control input-validation-error" type="password" data-val="true" data-val-required="The Password field is required." id="Password" name="Password" />
+            <input type="password" class="form-control input-validation-error" data-val="true" data-val-required="The Password field is required." id="Password" name="Password" />
             <span class="field-validation-error" data-valmsg-for="Password" data-valmsg-replace="true">The Password field is required.</span>
         </div>
         <div>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.CreateWarehouse.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.CreateWarehouse.html
index f5475cc0ab..9df160372c 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.CreateWarehouse.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.CreateWarehouse.html
@@ -2,7 +2,7 @@
 <body>
 <form action="/HtmlGeneration_Home/CreateWarehouse" method="post">        <div>
             <label class="warehouse" for="City">City</label>
-            <input size="50" type="text" data-val="true" data-val-minlength="The field City must be a string or array type with a minimum length of &#x27;2&#x27;." data-val-minlength-min="2" id="City" name="City" value="" />
+            <input type="text" size="50" data-val="true" data-val-minlength="The field City must be a string or array type with a minimum length of &#x27;2&#x27;." data-val-minlength-min="2" id="City" name="City" value="" />
             <span class="field-validation-valid" data-valmsg-for="City" data-valmsg-replace="true"></span>
         </div>
         <div>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Customer.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Customer.html
index b6b9557fca..a68479262d 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Customer.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Customer.html
@@ -3,7 +3,7 @@
     <form action="/Customer/HtmlGeneration_Customer" method="post">
         <div>
             <label class="order" for="Number">Number</label>
-            <input class="form-control" type="number" data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." id="Number" name="Number" value="" />
+            <input type="number" class="form-control" data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." id="Number" name="Number" value="" />
             <span class="field-validation-valid" data-valmsg-for="Number" data-valmsg-replace="true"></span>
         </div>
         <div>
@@ -21,7 +21,7 @@
         </div>
         <div>
             <label class="order" for="Password">Password</label>
-            <input class="form-control" type="password" data-val="true" data-val-required="The Password field is required." id="Password" name="Password" />
+            <input type="password" class="form-control" data-val="true" data-val-required="The Password field is required." id="Password" name="Password" />
             <span class="field-validation-valid" data-valmsg-for="Password" data-valmsg-replace="true"></span>
         </div>
         <div>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.EmployeeList.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.EmployeeList.html
index 531b893fc2..4239bd5a35 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.EmployeeList.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.EmployeeList.html
@@ -4,7 +4,7 @@
 <div>
     <label for="z0__Number">Number</label>
     <input data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." disabled="disabled" id="z0__Number" name="[0].Number" readonly="readonly" type="text" value="0" />
-    <input class="form-control" type="number" id="z0__Number" name="[0].Number" value="0" />
+    <input type="number" class="form-control" id="z0__Number" name="[0].Number" value="0" />
 </div>
 <div>
     <label class="employee" for="z0__Name">Name</label>
@@ -37,7 +37,7 @@ EmployeeName_0</textarea>
 <div>
     <label for="z1__Number">Number</label>
     <input data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." disabled="disabled" id="z1__Number" name="[1].Number" readonly="readonly" type="text" value="1" />
-    <input class="form-control" type="number" id="z1__Number" name="[1].Number" value="1" />
+    <input type="number" class="form-control" id="z1__Number" name="[1].Number" value="1" />
 </div>
 <div>
     <label class="employee" for="z1__Name">Name</label>
@@ -70,7 +70,7 @@ EmployeeName_1</textarea>
 <div>
     <label for="z2__Number">Number</label>
     <input data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." disabled="disabled" id="z2__Number" name="[2].Number" readonly="readonly" type="text" value="2" />
-    <input class="form-control" type="number" id="z2__Number" name="[2].Number" value="2" />
+    <input type="number" class="form-control" id="z2__Number" name="[2].Number" value="2" />
 </div>
 <div>
     <label class="employee" for="z2__Name">Name</label>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Image.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Image.html
index c851ccf084..a8557e52a3 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Image.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Image.html
@@ -15,7 +15,7 @@
     <img alt="Red versioned" title="Red versioned" src="/images/red.png?v=W2F5D366_nQ2fQqUk3URdgWy2ZekXjHzHJaY5yaiOOk" />
 
     <!-- Plain image tag with file version set to false -->
-    <img alt="Red explicitly not versioned" title="Red versioned" src="/images/red.png">
+    <img src="/images/red.png" alt="Red explicitly not versioned" title="Red versioned">
 
     <!-- Plain image tag with absolute path and file version -->
     <img alt="Absolute path versioned" src="http://contoso.com/hello/world">
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
index 401a11de37..642e4848b0 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.Encoded.html
@@ -20,7 +20,7 @@
     <link rel="stylesheet">
 
     <!-- Globbed link tag missing include but with static href -->
-    <link rel="stylesheet" href="HtmlEncode[[/site.css]]" />
+    <link href="HtmlEncode[[/site.css]]" rel="stylesheet" />
 
     <!-- Globbed link tag with missing file -->
     
@@ -32,13 +32,13 @@
     
 
     <!-- Globbed link tag with existing file and static href -->
-    <link rel="stylesheet" href="HtmlEncode[[/site.css]]" /><link rel="stylesheet" href="HtmlEncode[[/sub/site2.css]]" />
+    <link href="HtmlEncode[[/site.css]]" rel="stylesheet" /><link href="HtmlEncode[[/sub/site2.css]]" rel="stylesheet" />
 
     <!-- Globbed link tag with existing file and static href should dedupe -->
-    <link rel="stylesheet" href="HtmlEncode[[/site.css]]" />
+    <link href="HtmlEncode[[/site.css]]" rel="stylesheet" />
 
     <!-- Fallback to static href -->
-    <link rel="stylesheet" data-extra="test" title="&quot;the&quot; title" href="HtmlEncode[[/site.min.css?a=b&c=d]]" />
+    <link href="HtmlEncode[[/site.min.css?a=b&c=d]]" rel="stylesheet" data-extra="test" title="&quot;the&quot; title" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css?a=b&c=d]]"]);</script>
 
     <!-- Fallback from globbed href to static href -->
@@ -50,11 +50,11 @@
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback from globbed and static href to static href -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[site.min.css]]" /><link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.css]]" />
+    <link href="HtmlEncode[[site.min.css]]" rel="stylesheet" data-extra="test" /><link href="HtmlEncode[[/site.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback from globbed and static href with exclude to static href -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[site.min.css]]" />
+    <link href="HtmlEncode[[site.min.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback to static href with no primary href -->
@@ -62,19 +62,19 @@
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback to globbed href -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback to static and globbed href -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]","JavaScriptEncode[[/sub/site2.css]]"]);</script>
 
     <!-- Fallback to static and globbed href should dedupe -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback to static and globbed href with exclude -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]","JavaScriptEncode[[/sub/site2.css]]"]);</script>
 
     <!-- Fallback from globbed href to glbobed href -->
@@ -86,44 +86,44 @@
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback from globbed and static href to globbed href -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[site.min.css]]" /><link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.css]]" />
+    <link href="HtmlEncode[[site.min.css]]" rel="stylesheet" data-extra="test" /><link href="HtmlEncode[[/site.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Fallback from globbed and static href with exclude to globbed href -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[site.min.css]]">
+    <link href="HtmlEncode[[site.min.css]]" rel="stylesheet" data-extra="test">
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]"]);</script>
 
     <!-- Kitchen sink, all the attributes -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[site.min.css]]" />
+    <link href="HtmlEncode[[site.min.css]]" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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[[/site.css]]","JavaScriptEncode[[/sub/site2.css]]"]);</script>
 
     <!-- Fallback to globbed href that doesn't exist -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback to globbed href outside webroot -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback with missing attribute -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback with missing attribute -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback with missing attribute -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]" />
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test" />
 
     <!-- Plain link tag with file version -->
-    <link rel="stylesheet" href="HtmlEncode[[/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]" />
+    <link href="HtmlEncode[[/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]" rel="stylesheet" />
 
     <!-- Globbed link tag with existing file and file version -->
     <link rel="stylesheet" href="HtmlEncode[[/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]" />
 
     <!-- Fallback with file version -->
-    <link rel="stylesheet" data-extra="test" href="HtmlEncode[[/site.min.css]]">
+    <link href="HtmlEncode[[/site.min.css]]" rel="stylesheet" data-extra="test">
 <meta name="x-stylesheet-fallback-test" 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[[/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]"]);</script>
 
     <!-- Globbed link tag with existing file, static href and file version -->
-    <link rel="stylesheet" href="HtmlEncode[[/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]" /><link rel="stylesheet" href="HtmlEncode[[/sub/site2.css?v=30cxPex0tA9xEatW7f1Qhnn8tVLAHgE6xwIZhESq0y0]]" /><link rel="stylesheet" href="HtmlEncode[[/sub/site3.css?v=fSxxOr1Q4Dq2uPuzlju5UYGuK0SKABI-ghvaIGEsZDc]]" /><link rel="stylesheet" href="HtmlEncode[[/sub/site3.min.css?v=s8JMmAZxBn0dzuhRtQ0wgOvNBK4XRJRWEC2wfzsVF9M]]" />
+    <link href="HtmlEncode[[/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc]]" rel="stylesheet" /><link href="HtmlEncode[[/sub/site2.css?v=30cxPex0tA9xEatW7f1Qhnn8tVLAHgE6xwIZhESq0y0]]" rel="stylesheet" /><link href="HtmlEncode[[/sub/site3.css?v=fSxxOr1Q4Dq2uPuzlju5UYGuK0SKABI-ghvaIGEsZDc]]" rel="stylesheet" /><link href="HtmlEncode[[/sub/site3.min.css?v=s8JMmAZxBn0dzuhRtQ0wgOvNBK4XRJRWEC2wfzsVF9M]]" rel="stylesheet" />
 </head>
 <body>
 
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
index 15b5a344fe..a5c4e08137 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Link.html
@@ -20,7 +20,7 @@
     <link rel="stylesheet">
 
     <!-- Globbed link tag missing include but with static href -->
-    <link rel="stylesheet" href="/site.css" />
+    <link href="/site.css" rel="stylesheet" />
 
     <!-- Globbed link tag with missing file -->
     
@@ -32,13 +32,13 @@
     
 
     <!-- Globbed link tag with existing file and static href -->
-    <link rel="stylesheet" href="/site.css" /><link rel="stylesheet" href="/sub/site2.css" />
+    <link href="/site.css" rel="stylesheet" /><link href="/sub/site2.css" rel="stylesheet" />
 
     <!-- Globbed link tag with existing file and static href should dedupe -->
-    <link rel="stylesheet" href="/site.css" />
+    <link href="/site.css" rel="stylesheet" />
 
     <!-- Fallback to static href -->
-    <link rel="stylesheet" data-extra="test" title="&quot;the&quot; title" href="/site.min.css?a=b&amp;c=d" />
+    <link href="/site.min.css?a=b&amp;c=d" rel="stylesheet" data-extra="test" title="&quot;the&quot; title" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css?a=b\u0026c=d"]);</script>
 
     <!-- Fallback from globbed href to static href -->
@@ -50,11 +50,11 @@
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback from globbed and static href to static href -->
-    <link rel="stylesheet" data-extra="test" href="site.min.css" /><link rel="stylesheet" data-extra="test" href="/site.css" />
+    <link href="site.min.css" rel="stylesheet" data-extra="test" /><link href="/site.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback from globbed and static href with exclude to static href -->
-    <link rel="stylesheet" data-extra="test" href="site.min.css" />
+    <link href="site.min.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback to static href with no primary href -->
@@ -62,19 +62,19 @@
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback to globbed href -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback to static and globbed href -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css","\/sub\/site2.css"]);</script>
 
     <!-- Fallback to static and globbed href should dedupe -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback to static and globbed href with exclude -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css","\/sub\/site2.css"]);</script>
 
     <!-- Fallback from globbed href to glbobed href -->
@@ -86,44 +86,44 @@
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback from globbed and static href to globbed href -->
-    <link rel="stylesheet" data-extra="test" href="site.min.css" /><link rel="stylesheet" data-extra="test" href="/site.css" />
+    <link href="site.min.css" rel="stylesheet" data-extra="test" /><link href="/site.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Fallback from globbed and static href with exclude to globbed href -->
-    <link rel="stylesheet" data-extra="test" href="site.min.css">
+    <link href="site.min.css" rel="stylesheet" data-extra="test">
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css"]);</script>
 
     <!-- Kitchen sink, all the attributes -->
-    <link rel="stylesheet" data-extra="test" href="site.min.css" />
+    <link href="site.min.css" rel="stylesheet" data-extra="test" />
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css","\/sub\/site2.css"]);</script>
 
     <!-- Fallback to globbed href that doesn't exist -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback to globbed href outside webroot -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback with missing attribute -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback with missing attribute -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 
     <!-- Fallback with missing attribute -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css" />
+    <link href="/site.min.css" rel="stylesheet" data-extra="test" />
 
     <!-- Plain link tag with file version -->
-    <link rel="stylesheet" href="/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc" />
+    <link href="/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc" rel="stylesheet" />
 
     <!-- Globbed link tag with existing file and file version -->
     <link rel="stylesheet" href="/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc" />
 
     <!-- Fallback with file version -->
-    <link rel="stylesheet" data-extra="test" href="/site.min.css">
+    <link href="/site.min.css" rel="stylesheet" data-extra="test">
 <meta name="x-stylesheet-fallback-test" 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",["\/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc"]);</script>
 
     <!-- Globbed link tag with existing file, static href and file version -->
-    <link rel="stylesheet" href="/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc" /><link rel="stylesheet" href="/sub/site2.css?v=30cxPex0tA9xEatW7f1Qhnn8tVLAHgE6xwIZhESq0y0" /><link rel="stylesheet" href="/sub/site3.css?v=fSxxOr1Q4Dq2uPuzlju5UYGuK0SKABI-ghvaIGEsZDc" /><link rel="stylesheet" href="/sub/site3.min.css?v=s8JMmAZxBn0dzuhRtQ0wgOvNBK4XRJRWEC2wfzsVF9M" />
+    <link href="/site.css?v=XY7YsMemPf8AGU4SIX9ED9eOjK1LOQWu2dmCNmh-pQc" rel="stylesheet" /><link href="/sub/site2.css?v=30cxPex0tA9xEatW7f1Qhnn8tVLAHgE6xwIZhESq0y0" rel="stylesheet" /><link href="/sub/site3.css?v=fSxxOr1Q4Dq2uPuzlju5UYGuK0SKABI-ghvaIGEsZDc" rel="stylesheet" /><link href="/sub/site3.min.css?v=s8JMmAZxBn0dzuhRtQ0wgOvNBK4XRJRWEC2wfzsVF9M" rel="stylesheet" />
 </head>
 <body>
 
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.Encoded.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.Encoded.html
index 6bcfeecdc9..15249dd8d2 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.Encoded.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.Encoded.html
@@ -1,4 +1,4 @@
-<html>
+<html>
 <head>
     <meta charset="utf-8" />
     <title></title>
@@ -7,7 +7,7 @@
     <form action="HtmlEncode[[/HtmlGeneration_Order/Submit]]" method="HtmlEncode[[post]]">
         <div>
             <label class="order" for="HtmlEncode[[Shipping]]">HtmlEncode[[Shipping]]</label>
-            <input size="50" type="HtmlEncode[[text]]" id="HtmlEncode[[Shipping]]" name="HtmlEncode[[Shipping]]" value="HtmlEncode[[Your shipping method is UPSP]]" />
+            <input type="HtmlEncode[[text]]" size="50" id="HtmlEncode[[Shipping]]" name="HtmlEncode[[Shipping]]" value="HtmlEncode[[Your shipping method is UPSP]]" />
         </div>
         <div>
             <label class="order" for="HtmlEncode[[ShippingDateTime]]">HtmlEncode[[ShippingDateTime]]</label>
@@ -45,7 +45,7 @@
         </div>
         <div>
             <label class="order" for="HtmlEncode[[Customer_Number]]">HtmlEncode[[Number]]</label>
-            <input class="form-control" type="HtmlEncode[[number]]" data-val="HtmlEncode[[true]]" data-val-range="HtmlEncode[[The field Number must be between 1 and 100.]]" data-val-range-max="HtmlEncode[[100]]" data-val-range-min="HtmlEncode[[1]]" data-val-required="HtmlEncode[[The Number field is required.]]" id="HtmlEncode[[Customer_Number]]" name="HtmlEncode[[Customer.Number]]" value="HtmlEncode[[1]]" />
+            <input type="HtmlEncode[[number]]" class="form-control" data-val="HtmlEncode[[true]]" data-val-range="HtmlEncode[[The field Number must be between 1 and 100.]]" data-val-range-max="HtmlEncode[[100]]" data-val-range-min="HtmlEncode[[1]]" data-val-required="HtmlEncode[[The Number field is required.]]" id="HtmlEncode[[Customer_Number]]" name="HtmlEncode[[Customer.Number]]" value="HtmlEncode[[1]]" />
             <span class="HtmlEncode[[field-validation-valid]]" data-valmsg-for="HtmlEncode[[Customer.Number]]" data-valmsg-replace="HtmlEncode[[true]]"></span>
         </div>
         <div>
@@ -63,7 +63,7 @@
         </div>
         <div>
             <label class="order" for="HtmlEncode[[Customer_Password]]">HtmlEncode[[Password]]</label>
-            <input class="form-control" type="HtmlEncode[[password]]" data-val="HtmlEncode[[true]]" data-val-required="HtmlEncode[[The Password field is required.]]" id="HtmlEncode[[Customer_Password]]" name="HtmlEncode[[Customer.Password]]" />
+            <input type="HtmlEncode[[password]]" class="form-control" data-val="HtmlEncode[[true]]" data-val-required="HtmlEncode[[The Password field is required.]]" id="HtmlEncode[[Customer_Password]]" name="HtmlEncode[[Customer.Password]]" />
             <span class="HtmlEncode[[field-validation-valid]]" data-valmsg-for="HtmlEncode[[Customer.Password]]" data-valmsg-replace="HtmlEncode[[true]]"></span>
         </div>
         <div>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.html
index 69df8c30d2..6bd3544760 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Order.html
@@ -1,4 +1,4 @@
-<html>
+<html>
 <head>
     <meta charset="utf-8" />
     <title></title>
@@ -7,7 +7,7 @@
     <form action="/HtmlGeneration_Order/Submit" method="post">
         <div>
             <label class="order" for="Shipping">Shipping</label>
-            <input size="50" type="text" id="Shipping" name="Shipping" value="Your shipping method is UPSP" />
+            <input type="text" size="50" id="Shipping" name="Shipping" value="Your shipping method is UPSP" />
         </div>
         <div>
             <label class="order" for="ShippingDateTime">ShippingDateTime</label>
@@ -45,7 +45,7 @@
         </div>
         <div>
             <label class="order" for="Customer_Number">Number</label>
-            <input class="form-control" type="number" data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." id="Customer_Number" name="Customer.Number" value="1" />
+            <input type="number" class="form-control" data-val="true" data-val-range="The field Number must be between 1 and 100." data-val-range-max="100" data-val-range-min="1" data-val-required="The Number field is required." id="Customer_Number" name="Customer.Number" value="1" />
             <span class="field-validation-valid" data-valmsg-for="Customer.Number" data-valmsg-replace="true"></span>
         </div>
         <div>
@@ -63,7 +63,7 @@
         </div>
         <div>
             <label class="order" for="Customer_Password">Password</label>
-            <input class="form-control" type="password" data-val="true" data-val-required="The Password field is required." id="Customer_Password" name="Customer.Password" />
+            <input type="password" class="form-control" data-val="true" data-val-required="The Password field is required." id="Customer_Password" name="Customer.Password" />
             <span class="field-validation-valid" data-valmsg-for="Customer.Password" data-valmsg-replace="true"></span>
         </div>
         <div>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.Encoded.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.Encoded.html
index 6019532ad0..3774684a26 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.Encoded.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.Encoded.html
@@ -1,4 +1,4 @@
-<html>
+<html>
 <head>
     <meta charset="utf-8" />
     <title></title>
@@ -7,7 +7,7 @@
     <form method="get" action="HtmlEncode[[/HtmlGeneration_Home/ProductSubmit]]">
         <div>
             <label class="product" for="HtmlEncode[[HomePage]]">HtmlEncode[[HomePage]]</label>
-            <input size="50" type="HtmlEncode[[url]]" id="HtmlEncode[[HomePage]]" name="HtmlEncode[[HomePage]]" value="HtmlEncode[[http://www.contoso.com/]]" />
+            <input type="HtmlEncode[[url]]" size="50" id="HtmlEncode[[HomePage]]" name="HtmlEncode[[HomePage]]" value="HtmlEncode[[http://www.contoso.com/]]" />
         </div>
         <div>
             <label class="product" for="HtmlEncode[[Description]]">HtmlEncode[[Description]]</label>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.html
index b6176ea4ae..a7e6d03314 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Product.html
@@ -1,4 +1,4 @@
-<html>
+<html>
 <head>
     <meta charset="utf-8" />
     <title></title>
@@ -7,7 +7,7 @@
     <form method="get" action="/HtmlGeneration_Home/ProductSubmit">
         <div>
             <label class="product" for="HomePage">HomePage</label>
-            <input size="50" type="url" id="HomePage" name="HomePage" value="http://www.contoso.com/" />
+            <input type="url" size="50" id="HomePage" name="HomePage" value="http://www.contoso.com/" />
         </div>
         <div>
             <label class="product" for="Description">Description</label>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.ProductList.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.ProductList.html
index 61526e7cdc..beb60a138c 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.ProductList.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.ProductList.html
@@ -1,11 +1,11 @@
-<html>
+<html>
 <head>
     <meta charset="utf-8" />
 </head>
 <body>
 <form action="/HtmlGeneration_Product" method="post">            <div>
                 <label class="product" for="z0__HomePage">HomePage</label>
-                <input size="50" disabled="disabled" readonly="readonly" type="url" id="z0__HomePage" name="[0].HomePage" value="http://www.contoso.com/" />
+                <input type="url" size="50" disabled="disabled" readonly="readonly" id="z0__HomePage" name="[0].HomePage" value="http://www.contoso.com/" />
             </div>
 
 <div>
@@ -22,7 +22,7 @@
 </textarea>
 </div>            <div>
                 <label class="product" for="z1__HomePage">HomePage</label>
-                <input size="50" disabled="disabled" readonly="readonly" type="url" id="z1__HomePage" name="[1].HomePage" value="" />
+                <input type="url" size="50" disabled="disabled" readonly="readonly" id="z1__HomePage" name="[1].HomePage" value="" />
             </div>
 
 <div>
@@ -39,7 +39,7 @@
 </textarea>
 </div>            <div>
                 <label class="product" for="z2__HomePage">HomePage</label>
-                <input size="50" disabled="disabled" readonly="readonly" type="url" id="z2__HomePage" name="[2].HomePage" value="" />
+                <input type="url" size="50" disabled="disabled" readonly="readonly" id="z2__HomePage" name="[2].HomePage" value="" />
             </div>
 
 <div>
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html
index 686f5cd516..40810ebd8f 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.Encoded.html
@@ -10,15 +10,15 @@
         // Regular script with comment in body, and extra properties.
     </script>
 
-    <script data-foo="foo-data2" title="&lt;the title>" src="HtmlEncode[[/blank.js?a=b&c=d]]">
+    <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 JavaScriptEncode[[data-foo]]=\"JavaScriptEncode[[foo-data2]]\" JavaScriptEncode[[title]]=\"JavaScriptEncode[[&lt;the title>]]\" src=\"JavaScriptEncode[[/site.js?a=b&c=d]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[/site.js?a=b&c=d]]\" JavaScriptEncode[[data-foo]]=\"JavaScriptEncode[[foo-data2]]\" JavaScriptEncode[[title]]=\"JavaScriptEncode[[&lt;the title>]]\"><\/script>"));</script>
 
-    <script title="&quot;the&quot; title" src="HtmlEncode[[/blank.js]]">
+    <script src="HtmlEncode[[/blank.js]]" title="&quot;the&quot; title">
         // Fallback to globbed src
     </script>
-<script>(false||document.write("<script JavaScriptEncode[[title]]=\"JavaScriptEncode[["the" title]]\" src=\"JavaScriptEncode[[/site.js]]\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"JavaScriptEncode[[/site.js]]\" JavaScriptEncode[[title]]=\"JavaScriptEncode[["the" title]]\"><\/script>"));</script>
 
     <script src="HtmlEncode[[/blank.js]]">
         // Fallback to globbed src with exclude
diff --git a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html
index bc5d840b07..0693b89243 100644
--- a/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html
+++ b/test/Microsoft.AspNet.Mvc.FunctionalTests/compiler/resources/HtmlGenerationWebSite.HtmlGeneration_Home.Script.html
@@ -10,15 +10,15 @@
         // Regular script with comment in body, and extra properties.
     </script>
 
-    <script data-foo="foo-data2" title="&lt;the title>" src="/blank.js?a=b&amp;c=d">
+    <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 data-foo=\"foo-data2\" title=\"\u0026lt;the title\u003E\" src=\"\/site.js?a=b\u0026c=d\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"\/site.js?a=b\u0026c=d\" data-foo=\"foo-data2\" title=\"\u0026lt;the title\u003E\"><\/script>"));</script>
 
-    <script title="&quot;the&quot; title" src="/blank.js">
+    <script src="/blank.js" title="&quot;the&quot; title">
         // Fallback to globbed src
     </script>
-<script>(false||document.write("<script title=\"\u0022the\u0022 title\" src=\"\/site.js\"><\/script>"));</script>
+<script>(false||document.write("<script src=\"\/site.js\" title=\"\u0022the\u0022 title\"><\/script>"));</script>
 
     <script src="/blank.js">
         // Fallback to globbed src with exclude
diff --git a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/InputTagHelperTest.cs b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/InputTagHelperTest.cs
index da060f0cfa..b2045e356d 100644
--- a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/InputTagHelperTest.cs
+++ b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/InputTagHelperTest.cs
@@ -536,8 +536,8 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
             var expectedAttributes = new TagHelperAttributeList
             {
                 { "class", "form-control radio-control" },
-                { "type", inputTypeName ?? "radio" },       // Generator restores type attribute; adds "radio" if none.
                 { "value", value },
+                { "type", inputTypeName ?? "radio" },       // Generator restores type attribute; adds "radio" if none.
             };
             var expectedPreContent = "original pre-content";
             var expectedContent = "original content";
diff --git a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/LinkTagHelperTest.cs b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
index 2d6f8b4387..f4cdbb419f 100644
--- a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
+++ b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
@@ -388,8 +388,8 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
 
             // Assert
             Assert.Equal("rel", output.Attributes[0].Name);
-            Assert.Equal("data-extra", output.Attributes[1].Name);
-            Assert.Equal("href", output.Attributes[2].Name);
+            Assert.Equal("href", output.Attributes[1].Name);
+            Assert.Equal("data-extra", output.Attributes[2].Name);
         }
 
         public static TheoryData DoesNotRunWhenARequiredAttributeIsMissing_Data
diff --git a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
index 8d9953f195..488014bc6a 100644
--- a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
+++ b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
@@ -589,8 +589,8 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
 
             // Assert
             Assert.Equal("data-extra", output.Attributes[0].Name);
-            Assert.Equal("data-more", output.Attributes[1].Name);
-            Assert.Equal("src", output.Attributes[2].Name);
+            Assert.Equal("src", output.Attributes[1].Name);
+            Assert.Equal("data-more", output.Attributes[2].Name);
             Assert.Empty(logger.Logged);
         }
 
diff --git a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs
index 78c60a0815..c86dff02a8 100644
--- a/test/Microsoft.AspNet.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs
+++ b/test/Microsoft.AspNet.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs
@@ -8,13 +8,345 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Razor.Runtime.TagHelpers;
 using Microsoft.AspNet.Testing;
-using Microsoft.Framework.WebEncoders.Testing;
 using Xunit;
 
 namespace Microsoft.AspNet.Mvc.TagHelpers
 {
     public class TagHelperOutputExtensionsTest
     {
+        public static TheoryData CopyHtmlAttributeData_MaintainsOrder
+        {
+            get
+            {
+                // attributeNameToCopy, outputAttributes, allAttributes, expectedAttributes
+                return new TheoryData<
+                    string,
+                    TagHelperAttributeList,
+                    TagHelperAttributeList,
+                    IEnumerable<TagHelperAttribute>>
+                {
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "second", "B" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "second", "B" }
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("second", "B"),
+                        }
+                    },
+                    {
+                        "second",
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "second", "B" },
+                            { "second", "Duplicate B" },
+                            { "first", "A" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("second", "B"),
+                            new TagHelperAttribute("second", "Duplicate B"),
+                            new TagHelperAttribute("first", "A"),
+                        }
+                    },
+                    {
+                        "second",
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "second", "B" },
+                            { "first", "A" },
+                            { "second", "Duplicate B" }
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("second", "B"),
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("second", "Duplicate B"),
+                        }
+                    },
+                    {
+                        "dynamic",
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "second", "B" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "dynamic", "value" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("second", "B"),
+                            new TagHelperAttribute("dynamic", "value"),
+                        }
+                    },
+                    {
+                        "second",
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "dynamic", "value" },
+                            { "secondDynamic", "another value"}
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "second", "B" }
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("dynamic", "value"),
+                            new TagHelperAttribute("secondDynamic", "another value"),
+                            new TagHelperAttribute("second", "B"),
+                        }
+                    },
+                    {
+                        "second",
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "dynamic", "value" },
+                            { "secondDynamic", "another value"}
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "second", "B" }
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("second", "B"),
+                            new TagHelperAttribute("dynamic", "value"),
+                            new TagHelperAttribute("secondDynamic", "another value"),
+                        }
+                    },
+                    {
+                        "third",
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "dynamic", "value" },
+                            { "secondDynamic", "another value"}
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "second", "B" },
+                            { "third", "C" }
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("third", "C"),
+                            new TagHelperAttribute("dynamic", "value"),
+                            new TagHelperAttribute("secondDynamic", "another value"),
+                        }
+                    },
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "third", "C" },
+                            { "dynamic", "value" },
+                            { "secondDynamic", "another value"}
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "second", "B" },
+                            { "third", "C" }
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("third", "C"),
+                            new TagHelperAttribute("dynamic", "value"),
+                            new TagHelperAttribute("secondDynamic", "another value"),
+                        }
+                    },
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "third", "C" },
+                            { "dynamic", "value" },
+                            { "secondDynamic", "another value"}
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "secondDynamic", "another value"},
+                            { "second", "B" },
+                            { "third", "C" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("third", "C"),
+                            new TagHelperAttribute("dynamic", "value"),
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("secondDynamic", "another value"),
+                        }
+                    },
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "third", "C" },
+                            { "dynamic", "value" },
+                            { "secondDynamic", "another value"}
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "secondDynamic", "another value"},
+                            { "first", "Second first" },
+                            { "second", "B" },
+                            { "third", "C" },
+                            { "first", "third first" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("third", "C"),
+                            new TagHelperAttribute("first", "third first"),
+                            new TagHelperAttribute("dynamic", "value"),
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("secondDynamic", "another value"),
+                            new TagHelperAttribute("first", "Second first"),
+                        }
+                    },
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "third", "C" },
+                            { "third", "Duplicate Third" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "third", "C" },
+                            { "first", "A" },
+                            { "third", "Duplicate Third" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("third", "C"),
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("third", "Duplicate Third"),
+                        }
+                    },
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "third", "C" },
+                            { "third", "Duplicate Third" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "third", "C" },
+                            { "third", "Duplicate Third" },
+                            { "first", "A" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("third", "C"),
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("third", "Duplicate Third"),
+                        }
+                    },
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "third", "D" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "first", "A" },
+                            { "first", "B" },
+                            { "first", "C" },
+                            { "third", "D" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("first", "C"),
+                            new TagHelperAttribute("first", "B"),
+                            new TagHelperAttribute("third", "D"),
+                        }
+                    },
+                    {
+                        "first",
+                        new TagHelperAttributeList
+                        {
+                            { "third", "D" },
+                            { "dynamic", "value" },
+                            { "third", "Duplicate Third" },
+                        },
+                        new TagHelperAttributeList
+                        {
+                            { "third", "D" },
+                            { "first", "A" },
+                            { "third", "Duplicate Third" },
+                            { "first", "B" },
+                            { "first", "C" },
+                        },
+                        new[]
+                        {
+                            new TagHelperAttribute("third", "D"),
+                            new TagHelperAttribute("first", "A"),
+                            new TagHelperAttribute("first", "B"),
+                            new TagHelperAttribute("first", "C"),
+                            new TagHelperAttribute("dynamic", "value"),
+                            new TagHelperAttribute("third", "Duplicate Third"),
+                        }
+                    },
+                };
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(CopyHtmlAttributeData_MaintainsOrder))]
+        public void CopyHtmlAttribute_MaintainsOrder(
+            string attributeNameToCopy,
+            TagHelperAttributeList outputAttributes,
+            TagHelperAttributeList allAttributes,
+            IEnumerable<TagHelperAttribute> expectedAttributes)
+        {
+            // Arrange
+            var output = new TagHelperOutput("p", attributes: new TagHelperAttributeList(outputAttributes));
+            var context = new TagHelperContext(
+                allAttributes,
+                items: new Dictionary<object, object>(),
+                uniqueId: "test",
+                getChildContentAsync: useCachedResult => Task.FromResult<TagHelperContent>(result: null));
+
+            // Act
+            output.CopyHtmlAttribute(attributeNameToCopy, context);
+
+            // Assert
+            Assert.Equal(expectedAttributes, output.Attributes, CaseSensitiveTagHelperAttributeComparer.Default);
+        }
+
         public static TheoryData CopyHtmlAttributeData_MultipleAttributesSameName
         {
             get