diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Test/TagHelpers/UrlResolutionTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Test/TagHelpers/UrlResolutionTagHelperTest.cs
index 9da77a1783..c675a695b8 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Test/TagHelpers/UrlResolutionTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Test/TagHelpers/UrlResolutionTagHelperTest.cs
@@ -88,6 +88,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.TagHelpers
             var tagHelper = new UrlResolutionTagHelper(urlHelperFactory.Object, new HtmlTestEncoder());
 
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -144,6 +145,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.TagHelpers
             var tagHelper = new UrlResolutionTagHelper(urlHelperFactory.Object, new HtmlTestEncoder());
 
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -199,6 +201,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.TagHelpers
             var tagHelper = new UrlResolutionTagHelper(urlHelperFactory.Object, new HtmlTestEncoder());
 
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -254,6 +257,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.TagHelpers
             var tagHelper = new UrlResolutionTagHelper(urlHelperFactory.Object, new HtmlTestEncoder());
 
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -284,6 +288,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.TagHelpers
             var tagHelper = new UrlResolutionTagHelper(urlHelperFactory: null, htmlEncoder: null);
 
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -329,6 +334,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.TagHelpers
             var tagHelper = new UrlResolutionTagHelper(urlHelperFactory.Object, new HtmlTestEncoder());
 
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/AnchorTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/AnchorTagHelperTest.cs
index bb5c5e6921..2ae9c5fc3a 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/AnchorTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/AnchorTagHelperTest.cs
@@ -26,6 +26,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var metadataProvider = new TestModelMetadataProvider();
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "not-a",
                 allAttributes: new TagHelperAttributeList
                 {
                     { "id", "myanchor" },
@@ -93,6 +94,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -142,6 +144,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -193,6 +196,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -250,6 +254,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -308,6 +313,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "a",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -398,6 +404,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                                        "'asp-fragment' attribute.";
 
             var context = new TagHelperContext(
+                tagName: "test",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -433,6 +440,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 "'asp-route' must not have an 'asp-action' or 'asp-controller' attribute.";
 
             var context = new TagHelperContext(
+                tagName: "test",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagHelperTest.cs
index db85bc3d23..7d924ed536 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagHelperTest.cs
@@ -434,6 +434,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var cacheEntryOptions = new MemoryCacheEntryOptions()
                 .AddExpirationToken(new CancellationChangeToken(tokenSource.Token));
             var tagHelperContext = new TagHelperContext(
+                tagName: "cache",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: id);
@@ -661,6 +662,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private static TagHelperContext GetTagHelperContext(string id = "testid")
         {
             return new TagHelperContext(
+                tagName: "cache",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: id);
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagKeyTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagKeyTest.cs
index debed3c36f..0b5c083bc6 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagKeyTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/CacheTagKeyTest.cs
@@ -384,6 +384,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private static TagHelperContext GetTagHelperContext(string id = "testid")
         {
             return new TagHelperContext(
+                tagName: "test",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: id);
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/DistributedCacheTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/DistributedCacheTagHelperTest.cs
index 147c0574a1..49db965fdf 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/DistributedCacheTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/DistributedCacheTagHelperTest.cs
@@ -728,6 +728,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         private static TagHelperContext GetTagHelperContext()
         {
             return new TagHelperContext(
+                tagName: "test",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "testid");
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/EnvironmentTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/EnvironmentTagHelperTest.cs
index 57e73c997e..be53a4f6b9 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/EnvironmentTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/EnvironmentTagHelperTest.cs
@@ -214,7 +214,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers.Test
             attributes = attributes ?? new TagHelperAttributeList();
 
             return new TagHelperContext(
-                attributes,
+                tagName: "env",
+                allAttributes: attributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: Guid.NewGuid().ToString("N"));
         }
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormActionTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormActionTagHelperTest.cs
index bfe589702e..d58c865e58 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormActionTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormActionTagHelperTest.cs
@@ -26,6 +26,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var metadataProvider = new TestModelMetadataProvider();
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList
                 {
                     { "id", "my-id" },
@@ -100,6 +101,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var metadataProvider = new TestModelMetadataProvider();
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList
                 {
                     { "id", "my-id" },
@@ -203,6 +205,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -262,6 +265,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -339,6 +343,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -392,6 +397,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
         {
             // Arrange
             var context = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -472,6 +478,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 "'asp-action', 'asp-controller', 'asp-area', 'asp-fragment', or 'asp-route' attribute.";
 
             var context = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -507,6 +514,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 "elements with a specified 'asp-route' must not have an 'asp-action', 'asp-controller', or 'asp-fragment' attribute.";
 
             var context = new TagHelperContext(
+                tagName: "form-action",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormTagHelperTest.cs
index 9b3405306d..f4a51e12ba 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/FormTagHelperTest.cs
@@ -33,6 +33,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-form";
             var metadataProvider = new TestModelMetadataProvider();
             var tagHelperContext = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList
                 {
                     { "id", "myform" },
@@ -115,6 +116,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var viewContext = CreateViewContext();
             var expectedAttribute = new TagHelperAttribute("method", method.ToString().ToLowerInvariant());
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(new[] { expectedAttribute }),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -167,6 +169,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             // Arrange
             var testViewContext = CreateViewContext();
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -239,6 +242,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             // Arrange
             var viewContext = CreateViewContext();
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -291,6 +295,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "form";
             var metadataProvider = new TestModelMetadataProvider();
             var tagHelperContext = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList
                 {
                     { "id", "myform" },
@@ -356,6 +361,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             // Arrange
             var viewContext = CreateViewContext();
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -412,6 +418,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             // Arrange
             var viewContext = CreateViewContext();
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -468,6 +475,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             // Arrange
             var viewContext = CreateViewContext();
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -525,6 +533,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             // Arrange
             var viewContext = CreateViewContext();
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -606,6 +615,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                     return Task.FromResult<TagHelperContent>(tagHelperContent);
                 });
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -654,6 +664,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                                        "'asp-action', 'asp-controller', 'asp-fragment', 'asp-area', or 'asp-route' attribute.";
 
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -685,6 +696,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 "'asp-route' must not have an 'asp-action', 'asp-controller', or 'asp-fragment' attribute.";
 
             var context = new TagHelperContext(
+                tagName: "form",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ImageTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ImageTagHelperTest.cs
index 040df4b37d..a2159f251f 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ImageTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ImageTagHelperTest.cs
@@ -284,7 +284,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             TagHelperAttributeList attributes)
         {
             return new TagHelperContext(
-                attributes,
+                tagName: "image",
+                allAttributes: attributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: Guid.NewGuid().ToString("N"));
         }
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/InputTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/InputTagHelperTest.cs
index 6e443c5c5f..a92a669983 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/InputTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/InputTagHelperTest.cs
@@ -88,6 +88,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 "<input name=\"HtmlEncode[[IsACar]]\" type=\"HtmlEncode[[hidden]]\" value=\"HtmlEncode[[false]]\" />";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -135,6 +136,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             };
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -181,6 +183,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             };
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -224,6 +227,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             };
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -330,6 +334,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -409,6 +414,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 { "type", specifiedType },
             };
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: allAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -464,6 +470,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedPostContent = "original post-content";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -567,6 +574,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -669,6 +677,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -768,6 +777,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -879,6 +889,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -999,6 +1010,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -1069,6 +1081,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList()
                 {
                     {"type", "datetime" }
@@ -1154,6 +1167,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "not-input";
 
             var context = new TagHelperContext(
+                tagName: "input",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/Internal/AttributeMatcherTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/Internal/AttributeMatcherTest.cs
index 870fcc2620..a4aff7f9ab 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/Internal/AttributeMatcherTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/Internal/AttributeMatcherTest.cs
@@ -96,7 +96,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers.Internal
         private static TagHelperContext MakeTagHelperContext(TagHelperAttributeList attributes)
         {
             return new TagHelperContext(
-                attributes,
+                tagName: "test",
+                allAttributes: attributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: Guid.NewGuid().ToString("N"));
         }
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LabelTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LabelTagHelperTest.cs
index b8f8c9b680..5ea9683166 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LabelTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LabelTagHelperTest.cs
@@ -190,6 +190,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedPostContent = "original post-content";
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "not-label",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
index 1260e57083..1c18cf70cf 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/LinkTagHelperTest.cs
@@ -1001,7 +1001,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             attributes = attributes ?? new TagHelperAttributeList();
 
             return new TagHelperContext(
-                attributes,
+                tagName: "link",
+                allAttributes: attributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: Guid.NewGuid().ToString("N"));
         }
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/OptionTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/OptionTagHelperTest.cs
index 40b8f4a5ce..9aa2ad26dc 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/OptionTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/OptionTagHelperTest.cs
@@ -401,7 +401,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             }
 
             var tagHelperContext = new TagHelperContext(
-                contextAttributes,
+                tagName: "option",
+                allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
 
@@ -472,7 +473,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var originalPreContent = "original pre-content";
             var originalPostContent = "original post-content";
             var tagHelperContext = new TagHelperContext(
-                contextAttributes,
+                tagName: "option",
+                allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
             var output = new TagHelperOutput(
@@ -535,7 +537,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var originalPreContent = "original pre-content";
             var originalPostContent = "original post-content";
             var tagHelperContext = new TagHelperContext(
-                contextAttributes,
+                tagName: "option",
+                allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
 
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/RenderAtEndOfFormTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/RenderAtEndOfFormTagHelperTest.cs
index 1996ab83c1..03304ab18a 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/RenderAtEndOfFormTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/RenderAtEndOfFormTagHelperTest.cs
@@ -63,6 +63,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 });
 
             var tagHelperContext = new TagHelperContext(
+                "test",
                 new TagHelperAttributeList(),
                 new Dictionary<object, object>(),
                 "someId");
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
index 4a2e7f6241..7abb469556 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ScriptTagHelperTest.cs
@@ -908,7 +908,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             attributes = attributes ?? new TagHelperAttributeList();
 
             return new TagHelperContext(
-                attributes,
+                tagName: "script",
+                allAttributes: attributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: Guid.NewGuid().ToString("N"));
         }
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/SelectTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/SelectTagHelperTest.cs
index 65efd60719..61b358780c 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/SelectTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/SelectTagHelperTest.cs
@@ -201,6 +201,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var modelExpression = new ModelExpression(nameAndId.Name, modelExplorer);
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "select",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -290,6 +291,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var modelExpression = new ModelExpression(nameAndId.Name, modelExplorer);
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "select",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -380,6 +382,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "select";
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "select",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -468,6 +471,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var modelExpression = new ModelExpression(name: string.Empty, modelExplorer: modelExplorer);
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "select",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -556,7 +560,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedTagName = "select";
 
             var tagHelperContext = new TagHelperContext(
-                contextAttributes,
+                tagName: "select",
+                allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
 
@@ -638,7 +643,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var tagName = "select";
 
             var tagHelperContext = new TagHelperContext(
-                contextAttributes,
+                tagName: "select",
+                allAttributes: contextAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
             var output = new TagHelperOutput(
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs
index 3e70b3ffc6..bfe3ecf99c 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TagHelperOutputExtensionsTest.cs
@@ -340,7 +340,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(
                     new DefaultTagHelperContent()));
             var context = new TagHelperContext(
-                allAttributes,
+                tagName: "p",
+                allAttributes: allAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
 
@@ -441,7 +442,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 getChildContentAsync: (useCachedResult, encoder) => Task.FromResult<TagHelperContent>(
                     new DefaultTagHelperContent()));
             var context = new TagHelperContext(
-                allAttributes,
+                tagName: "p",
+                allAttributes: allAttributes,
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
 
@@ -468,6 +470,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                     return Task.FromResult<TagHelperContent>(tagHelperContent);
                 });
             var tagHelperContext = new TagHelperContext(
+                tagName: "p",
                 allAttributes: new TagHelperAttributeList
                 {
                     { attributeName, attributeValue }
@@ -503,6 +506,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 });
             var expectedAttribute = new TagHelperAttribute(attributeName, "world2");
             var tagHelperContext = new TagHelperContext(
+                tagName: "p",
                 allAttributes: new TagHelperAttributeList
                 {
                     { attributeName, "world" }
@@ -533,6 +537,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                     return Task.FromResult<TagHelperContent>(tagHelperContent);
                 });
             var tagHelperContext = new TagHelperContext(
+                tagName: "p",
                 allAttributes: new TagHelperAttributeList
                 {
                     { "hello", "world" }
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TextAreaTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TextAreaTagHelperTest.cs
index 3174573145..b6c9817a87 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TextAreaTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/TextAreaTagHelperTest.cs
@@ -124,6 +124,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             };
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "text-area",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationMessageTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationMessageTagHelperTest.cs
index be190e769a..4e2365bbb4 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationMessageTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationMessageTagHelperTest.cs
@@ -40,6 +40,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedPostContent = "original post-content";
 
             var tagHelperContext = new TagHelperContext(
+                tagName: "not-span",
                 allAttributes: new TagHelperAttributeList
                 {
                     { "id", "myvalidationmessage" },
@@ -114,6 +115,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedContent = "original content";
             var expectedPostContent = "original post-content";
             var context = new TagHelperContext(
+                tagName: "span",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -186,6 +188,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             output.Content.AppendHtml(outputContent);
 
             var context = new TagHelperContext(
+                tagName: "span",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -246,6 +249,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 });
 
             var context = new TagHelperContext(
+                tagName: "span",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
@@ -286,6 +290,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             output.PostContent.SetContent(expectedPostContent);
 
             var context = new TagHelperContext(
+                tagName: "span",
                 allAttributes: new TagHelperAttributeList(
                     Enumerable.Empty<TagHelperAttribute>()),
                 items: new Dictionary<object, object>(),
diff --git a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationSummaryTagHelperTest.cs b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationSummaryTagHelperTest.cs
index d4e5b0ede3..1b4ec3cc80 100644
--- a/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationSummaryTagHelperTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.TagHelpers.Test/ValidationSummaryTagHelperTest.cs
@@ -58,6 +58,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedPreContent = "original pre-content";
             var expectedContent = "original content";
             var tagHelperContext = new TagHelperContext(
+                tagName: "not-div",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -122,7 +123,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 });
 
             var context = new TagHelperContext(
-                new TagHelperAttributeList(),
+                tagName: "div",
+                allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
 
@@ -189,7 +191,8 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
                 });
 
             var context = new TagHelperContext(
-                new TagHelperAttributeList(),
+                tagName: "div",
+                allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
 
@@ -221,6 +224,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedPreContent = "original pre-content";
             var expectedContent = "original content";
             var tagHelperContext = new TagHelperContext(
+                tagName: "not-div",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -290,6 +294,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             var expectedPreContent = "original pre-content";
             var expectedContent = "original content";
             var tagHelperContext = new TagHelperContext(
+                tagName: "not-div",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -373,6 +378,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             validationSummaryTagHelper.ViewContext = expectedViewContext;
 
             var context = new TagHelperContext(
+                tagName: "div",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -428,6 +434,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             validationSummaryTagHelper.ViewContext = viewContext;
 
             var context = new TagHelperContext(
+                tagName: "div",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -486,6 +493,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             validationSummaryTagHelper.ViewContext = viewContext;
 
             var context = new TagHelperContext(
+                tagName: "div",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");
@@ -541,6 +549,7 @@ namespace Microsoft.AspNetCore.Mvc.TagHelpers
             validationSummaryTagHelper.ViewContext = viewContext;
 
             var context = new TagHelperContext(
+                tagName: "div",
                 allAttributes: new TagHelperAttributeList(),
                 items: new Dictionary<object, object>(),
                 uniqueId: "test");