From 8a054924076962c6d29188267bc7a00cc7d582ac Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 13 Mar 2024 15:27:46 +0100
Subject: [PATCH 01/11] Allow components in global namespace

---
 .../CSharp/BindTagHelperDescriptorProvider.cs |  3 +-
 .../ComponentTagHelperDescriptorProvider.cs   |  9 ++-
 ...EventHandlerTagHelperDescriptorProvider.cs |  3 +-
 .../CodeGeneration/CodeWriterExtensions.cs    | 32 +++++++--
 .../ComponentDocumentClassifierPass.cs        |  9 +--
 .../ComponentRenderModeDirectivePass.cs       |  3 +-
 .../Extensions/MetadataAttributePass.cs       |  8 ++-
 .../Language/RazorCodeDocumentExtensions.cs   | 30 ++++++---
 .../ViewComponentTagHelperPass.cs             |  3 +-
 .../AssemblyAttributeInjectionPass.cs         |  8 ++-
 .../ViewComponentTagHelperPass.cs             |  3 +-
 .../src/Mvc/ViewComponentTagHelperPass.cs     |  3 +-
 .../RazorSourceGeneratorComponentTests.cs     | 45 +++++++++++++
 .../EmptyRootNamespace/Component2_razor.g.cs  | 25 +++++++
 .../EmptyRootNamespace/Component3_razor.g.cs  | 27 ++++++++
 .../Shared_Component1_razor.g.cs              | 31 +++++++++
 .../EmptyRootNamespace/Views_Home_Index.html  |  6 ++
 .../Views_Home_Index_cshtml.g.cs              | 65 +++++++++++++++++++
 18 files changed, 282 insertions(+), 31 deletions(-)
 create mode 100644 src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component2_razor.g.cs
 create mode 100644 src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component3_razor.g.cs
 create mode 100644 src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Shared_Component1_razor.g.cs
 create mode 100644 src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index.html
 create mode 100644 src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs

diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/BindTagHelperDescriptorProvider.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/BindTagHelperDescriptorProvider.cs
index f916ea1e0ab..d806c859e57 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/BindTagHelperDescriptorProvider.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/BindTagHelperDescriptorProvider.cs
@@ -343,7 +343,8 @@ private ref struct DisplayNameHelper(INamedTypeSymbol type)
             private (string Type, string Namespace)? _names;
 
             public (string Type, string Namespace) GetNames()
-                => _names ??= (_type.ToDisplayString(), _type.ContainingNamespace.ToDisplayString());
+                => _names ??= (_type.ToDisplayString(),
+                    _type.ContainingNamespace.ToDisplayString(SymbolExtensions.FullNameTypeDisplayFormat));
         }
 
         private static TagHelperDescriptor CreateElementBindTagHelper(
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs
index 561cbb6d55e..0f53faceb9f 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs
@@ -115,8 +115,10 @@ private static TagHelperDescriptor CreateNameMatchingDescriptor(
 
             if (fullyQualified)
             {
-                var containingNamespace = type.ContainingNamespace.ToDisplayString();
-                var fullName = $"{containingNamespace}.{type.Name}";
+                var containingNamespace = type.ContainingNamespace.ToDisplayString(SymbolExtensions.FullNameTypeDisplayFormat);
+                var fullName = string.IsNullOrEmpty(containingNamespace)
+                    ? type.Name
+                    : $"{containingNamespace}.{type.Name}";
 
                 builder.TagMatchingRule(r =>
                 {
@@ -125,7 +127,8 @@ private static TagHelperDescriptor CreateNameMatchingDescriptor(
 
                 metadata.Add(ComponentMetadata.Component.NameMatchKey, ComponentMetadata.Component.FullyQualifiedNameMatch);
             }
-            else
+            // If the component is in the global namespace, skip adding this rule which is the same as the fully qualified one.
+            else if (!type.ContainingNamespace.IsGlobalNamespace)
             {
                 builder.TagMatchingRule(r =>
                 {
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/EventHandlerTagHelperDescriptorProvider.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/EventHandlerTagHelperDescriptorProvider.cs
index dbd1c00447a..058f6485b3e 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/EventHandlerTagHelperDescriptorProvider.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/EventHandlerTagHelperDescriptorProvider.cs
@@ -101,7 +101,8 @@ private ref struct DisplayNameHelper(INamedTypeSymbol type)
 
             public (string Type, string Namespace) GetNames()
             {
-                _names ??= (_type.ToDisplayString(), _type.ContainingNamespace.ToDisplayString());
+                _names ??= (_type.ToDisplayString(),
+                    _type.ContainingNamespace.ToDisplayString(SymbolExtensions.FullNameTypeDisplayFormat));
 
                 return _names.GetValueOrDefault();
             }
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/CodeGeneration/CodeWriterExtensions.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/CodeGeneration/CodeWriterExtensions.cs
index 4fbd31097e9..65bf9266eee 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/CodeGeneration/CodeWriterExtensions.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/CodeGeneration/CodeWriterExtensions.cs
@@ -392,12 +392,19 @@ private static CSharpCodeWritingScope BuildLambda(CodeWriter writer, bool async,
         return scope;
     }
 
-    public static CSharpCodeWritingScope BuildNamespace(this CodeWriter writer, string name)
+#nullable enable
+    public static CSharpCodeWritingScope BuildNamespace(this CodeWriter writer, string? name)
     {
+        if (name.IsNullOrEmpty())
+        {
+            return new CSharpCodeWritingScope(writer, writeBraces: false);
+        }
+
         writer.Write("namespace ").WriteLine(name);
 
         return new CSharpCodeWritingScope(writer);
     }
+#nullable disable
 
     public static CSharpCodeWritingScope BuildClassDeclaration(
         this CodeWriter writer,
@@ -658,13 +665,15 @@ public struct CSharpCodeWritingScope : IDisposable
     {
         private readonly CodeWriter _writer;
         private readonly bool _autoSpace;
+        private readonly bool _writeBraces;
         private readonly int _tabSize;
         private int _startIndent;
 
-        public CSharpCodeWritingScope(CodeWriter writer, bool autoSpace = true)
+        public CSharpCodeWritingScope(CodeWriter writer, bool autoSpace = true, bool writeBraces = true)
         {
             _writer = writer;
             _autoSpace = autoSpace;
+            _writeBraces = writeBraces;
             _tabSize = writer.TabSize;
             _startIndent = -1; // Set in WriteStartScope
 
@@ -680,7 +689,15 @@ private void WriteStartScope()
         {
             TryAutoSpace(" ");
 
-            _writer.WriteLine("{");
+            if (_writeBraces)
+            {
+                _writer.WriteLine("{");
+            }
+            else
+            {
+                _writer.WriteLine();
+            }
+
             _writer.CurrentIndent += _tabSize;
             _startIndent = _writer.CurrentIndent;
         }
@@ -695,7 +712,14 @@ private void WriteEndScope()
                 _writer.CurrentIndent -= _tabSize;
             }
 
-            _writer.WriteLine("}");
+            if (_writeBraces)
+            {
+                _writer.WriteLine("}");
+            }
+            else
+            {
+                _writer.WriteLine();
+            }
         }
 
         private void TryAutoSpace(string spaceCharacter)
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs
index 1cd3b31f79a..19607ae27f4 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs
@@ -62,12 +62,13 @@ protected override void OnDocumentStructureCreated(
         ClassDeclarationIntermediateNode @class,
         MethodDeclarationIntermediateNode method)
     {
-        if (!codeDocument.TryComputeNamespace(fallbackToRootNamespace: true, out var computedNamespace) ||
-            !TryComputeClassName(codeDocument, out var computedClass))
+        if (!codeDocument.TryComputeNamespace(fallbackToRootNamespace: true, allowEmptyRootNamespace: true, out var computedNamespace))
         {
-            // If we can't compute a nice namespace (no relative path) then just generate something
-            // mangled.
             computedNamespace = FallbackRootNamespace;
+        }
+
+        if (!TryComputeClassName(codeDocument, out var computedClass))
+        {
             var checksum = ChecksumUtilities.BytesToString(codeDocument.Source.Text.GetChecksum());
             computedClass = $"AspNetCore_{checksum}";
         }
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentRenderModeDirectivePass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentRenderModeDirectivePass.cs
index f19128ad9a6..006f1889a9c 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentRenderModeDirectivePass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentRenderModeDirectivePass.cs
@@ -89,10 +89,11 @@ child is not DirectiveTokenIntermediateNode directiveToken
 
         // generate the attribute usage on top of the class
         var attributeNode = new CSharpCodeIntermediateNode();
+        var namespaceSeparator = string.IsNullOrEmpty(@namespace.Content) ? string.Empty : ".";
         attributeNode.Children.Add(new IntermediateToken()
         {
             Kind = TokenKind.CSharp,
-            Content = $"[global::{@namespace.Content}.{@class.ClassName}.{GeneratedRenderModeAttributeName}]",
+            Content = $"[global::{@namespace.Content}{namespaceSeparator}{@class.ClassName}.{GeneratedRenderModeAttributeName}]",
         });
 
         // Insert the new attribute on top of the class
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Extensions/MetadataAttributePass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Extensions/MetadataAttributePass.cs
index f9384ead685..3a94798f05e 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Extensions/MetadataAttributePass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Extensions/MetadataAttributePass.cs
@@ -41,9 +41,9 @@ protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentInte
         //
         // If we can't use [RazorCompiledItem] then we don't care about the rest of the attributes.
         var @namespace = documentNode.FindPrimaryNamespace();
-        if (@namespace == null || string.IsNullOrEmpty(@namespace.Content))
+        if (@namespace == null)
         {
-            // No namespace node or it's incomplete. Skip.
+            // No namespace node. Skip.
             return;
         }
 
@@ -70,7 +70,9 @@ protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentInte
         // [RazorCompiledItem] is an [assembly: ... ] attribute, so it needs to be applied at the global scope.
         documentNode.Children.Insert(0, new RazorCompiledItemAttributeIntermediateNode()
         {
-            TypeName = @namespace.Content + "." + @class.ClassName,
+            TypeName = string.IsNullOrEmpty(@namespace.Content)
+                ? @class.ClassName
+                : @namespace.Content + "." + @class.ClassName,
             Kind = documentNode.DocumentKind,
             Identifier = identifier,
         });
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs
index ae0c3aa645b..396d2d89b07 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs
@@ -303,12 +303,15 @@ public static bool TryComputeClassName(this RazorCodeDocument codeDocument, [Not
     }
 #nullable disable
 
+    public static bool TryComputeNamespace(this RazorCodeDocument document, bool fallbackToRootNamespace, out string @namespace)
+        => TryComputeNamespace(document, fallbackToRootNamespace: fallbackToRootNamespace, allowEmptyRootNamespace: false, out @namespace);
+
     // In general documents will have a relative path (relative to the project root).
     // We can only really compute a nice namespace when we know a relative path.
     //
     // However all kinds of thing are possible in tools. We shouldn't barf here if the document isn't
     // set up correctly.
-    public static bool TryComputeNamespace(this RazorCodeDocument document, bool fallbackToRootNamespace, out string @namespace)
+    internal static bool TryComputeNamespace(this RazorCodeDocument document, bool fallbackToRootNamespace, bool allowEmptyRootNamespace, out string @namespace)
     {
         if (document == null)
         {
@@ -318,7 +321,7 @@ public static bool TryComputeNamespace(this RazorCodeDocument document, bool fal
         @namespace = (string)document.Items[NamespaceKey];
         if (@namespace is null)
         {
-            var result = TryComputeNamespaceCore(document, fallbackToRootNamespace, out @namespace);
+            var result = TryComputeNamespaceCore(document, fallbackToRootNamespace: fallbackToRootNamespace, allowEmptyRootNamespace: allowEmptyRootNamespace, out @namespace);
             document.Items[NamespaceKey] = @namespace;
             return result;
         }
@@ -326,14 +329,14 @@ public static bool TryComputeNamespace(this RazorCodeDocument document, bool fal
 #if DEBUG
         // In debug mode, even if we're cached, lets take the hit to run this again and make sure the cached value is correct.
         // This is to help us find issues with caching logic during development.
-        var validateResult = TryComputeNamespaceCore(document, fallbackToRootNamespace, out var validateNamespace);
+        var validateResult = TryComputeNamespaceCore(document, fallbackToRootNamespace: fallbackToRootNamespace, allowEmptyRootNamespace: allowEmptyRootNamespace, out var validateNamespace);
         Debug.Assert(validateResult, "We couldn't compute the namespace, but have a cached value, so something has gone wrong");
         Debug.Assert(validateNamespace == @namespace, $"We cached a namespace of {@namespace} but calculated that it should be {validateNamespace}");
 #endif
 
         return true;
 
-        bool TryComputeNamespaceCore(RazorCodeDocument document, bool fallbackToRootNamespace, out string @namespace)
+        bool TryComputeNamespaceCore(RazorCodeDocument document, bool fallbackToRootNamespace, bool allowEmptyRootNamespace, out string @namespace)
         {
             var filePath = document.Source.FilePath;
             if (filePath == null || document.Source.RelativePath == null || filePath.Length < document.Source.RelativePath.Length)
@@ -397,11 +400,18 @@ bool TryComputeNamespaceCore(RazorCodeDocument document, bool fallbackToRootName
                 var options = document.GetCodeGenerationOptions() ?? document.GetDocumentIntermediateNode()?.Options;
                 baseNamespace = options?.RootNamespace;
                 appendSuffix = true;
-            }
 
-            if (string.IsNullOrEmpty(baseNamespace))
+                // null means RootNamespace wasn't set yet, so we fail for now, tooling seems to rely on this
+                if (baseNamespace is null ||
+                    (!allowEmptyRootNamespace && string.IsNullOrEmpty(baseNamespace)))
+                {
+                    @namespace = null;
+                    return false;
+                }
+            }
+            else
             {
-                // There was no valid @namespace directive and we couldn't compute the RootNamespace.
+                // There was no valid @namespace directive.
                 @namespace = null;
                 return false;
             }
@@ -444,7 +454,11 @@ bool TryComputeNamespaceCore(RazorCodeDocument document, bool fallbackToRootName
 
                     previousLength = builder.Length;
 
-                    builder.Append('.');
+                    if (previousLength != 0)
+                    {
+                        builder.Append('.');
+                    }
+
                     CSharpIdentifier.AppendSanitized(builder, token);
                 }
 
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version1_X/ViewComponentTagHelperPass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version1_X/ViewComponentTagHelperPass.cs
index fdeb8db13dc..da44cacbf7c 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version1_X/ViewComponentTagHelperPass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version1_X/ViewComponentTagHelperPass.cs
@@ -173,7 +173,8 @@ public bool Add(TagHelperDescriptor tagHelper)
             }
 
             var className = $"__Generated__{tagHelper.GetViewComponentName()}ViewComponentTagHelper";
-            var fullyQualifiedName = $"{Namespace.Content}.{Class.ClassName}.{className}";
+            var namespaceSeparator = string.IsNullOrEmpty(Namespace.Content) ? string.Empty : ".";
+            var fullyQualifiedName = $"{Namespace.Content}{namespaceSeparator}{Class.ClassName}.{className}";
             var fieldName = GenerateFieldName(tagHelper);
 
             _tagHelpers.Add(tagHelper, (className, fullyQualifiedName, fieldName));
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/AssemblyAttributeInjectionPass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/AssemblyAttributeInjectionPass.cs
index 49262fca725..42e9c5532ea 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/AssemblyAttributeInjectionPass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/AssemblyAttributeInjectionPass.cs
@@ -23,9 +23,9 @@ protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentInte
         }
 
         var @namespace = documentNode.FindPrimaryNamespace();
-        if (@namespace == null || string.IsNullOrEmpty(@namespace.Content))
+        if (@namespace == null)
         {
-            // No namespace node or it's incomplete. Skip.
+            // No namespace node. Skip.
             return;
         }
 
@@ -36,7 +36,9 @@ protected override void ExecuteCore(RazorCodeDocument codeDocument, DocumentInte
             return;
         }
 
-        var generatedTypeName = $"{@namespace.Content}.{@class.ClassName}";
+        var generatedTypeName = string.IsNullOrEmpty(@namespace.Content)
+            ? @class.ClassName
+            : $"{@namespace.Content}.{@class.ClassName}";
 
         // The MVC attributes require a relative path to be specified so that we can make a view engine path.
         // We can't use a rooted path because we don't know what the project root is.
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/ViewComponentTagHelperPass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/ViewComponentTagHelperPass.cs
index 10eb289f0a5..cbacadea315 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/ViewComponentTagHelperPass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc.Version2_X/ViewComponentTagHelperPass.cs
@@ -173,7 +173,8 @@ public bool Add(TagHelperDescriptor tagHelper)
             }
 
             var className = $"__Generated__{tagHelper.GetViewComponentName()}ViewComponentTagHelper";
-            var fullyQualifiedName = $"{Namespace.Content}.{Class.ClassName}.{className}";
+            var namespaceSeparator = string.IsNullOrEmpty(Namespace.Content) ? string.Empty : ".";
+            var fullyQualifiedName = $"{Namespace.Content}{namespaceSeparator}{Class.ClassName}.{className}";
             var fieldName = GenerateFieldName(tagHelper);
 
             _tagHelpers.Add(tagHelper, (className, fullyQualifiedName, fieldName));
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc/ViewComponentTagHelperPass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc/ViewComponentTagHelperPass.cs
index 2b3bba4acfe..4e06db45ae6 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc/ViewComponentTagHelperPass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Mvc/ViewComponentTagHelperPass.cs
@@ -180,7 +180,8 @@ public bool Add(TagHelperDescriptor tagHelper)
             }
 
             var className = $"__Generated__{tagHelper.GetViewComponentName()}ViewComponentTagHelper";
-            var fullyQualifiedName = $"{Namespace.Content}.{Class.ClassName}.{className}";
+            var namespaceSeparator = string.IsNullOrEmpty(Namespace.Content) ? string.Empty : ".";
+            var fullyQualifiedName = $"{Namespace.Content}{namespaceSeparator}{Class.ClassName}.{className}";
             var fieldName = GenerateFieldName(tagHelper);
 
             _tagHelpers.Add(tagHelper, (className, fullyQualifiedName, fieldName));
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorComponentTests.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorComponentTests.cs
index 3d5d1691c3e..e52287dab7b 100644
--- a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorComponentTests.cs
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/RazorSourceGeneratorComponentTests.cs
@@ -143,6 +143,51 @@ Hello from Derived
         await VerifyRazorPageMatchesBaselineAsync(compilation, "Views_Home_Index");
     }
 
+    [Fact, WorkItem("https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1954771")]
+    public async Task EmptyRootNamespace()
+    {
+        // Arrange
+        var project = CreateTestProject(new()
+        {
+            ["Views/Home/Index.cshtml"] = """
+                @(await Html.RenderComponentAsync<Shared.Component1>(RenderMode.Static))
+                @(await Html.RenderComponentAsync<Component3>(RenderMode.Static))
+                """,
+            ["Shared/Component1.razor"] = """
+                Component1 in Shared namespace
+                <Component2 />
+                <Component4 />
+                """,
+            ["Component2.razor"] = """
+                Component2 in global namespace
+                """,
+            ["Component3.razor"] = """
+                Component3 in global namespace
+                <Shared.Component1 />
+                """
+        }, new()
+        {
+            ["Component4.cs"] = """
+                using Microsoft.AspNetCore.Components;
+                public class Component4 : ComponentBase { }
+                """,
+        });
+        var compilation = await project.GetCompilationAsync();
+        var driver = await GetDriverAsync(project, options =>
+        {
+            options.TestGlobalOptions["build_property.RootNamespace"] = string.Empty;
+        });
+
+        // Act
+        var result = RunGenerator(compilation!, ref driver, out compilation);
+
+        // Assert
+        Assert.Empty(result.Diagnostics);
+        Assert.Equal(4, result.GeneratedSources.Length);
+        result.VerifyOutputsMatchBaseline();
+        await VerifyRazorPageMatchesBaselineAsync(compilation, "Views_Home_Index");
+    }
+
     [Theory, CombinatorialData]
     public async Task AddComponentParameter(
         [CombinatorialValues("7.0", "8.0", "Latest")] string langVersion)
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component2_razor.g.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component2_razor.g.cs
new file mode 100644
index 00000000000..886009739d0
--- /dev/null
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component2_razor.g.cs
@@ -0,0 +1,25 @@
+#pragma checksum "Component2.razor" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "64a0fe8849732339e8ebc4698ec7367617b7b588"
+// <auto-generated/>
+#pragma warning disable 1591
+
+    #line default
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    #line default
+    #line hidden
+    #nullable restore
+    public partial class Component2 : global::Microsoft.AspNetCore.Components.ComponentBase
+    #nullable disable
+    {
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __builder.AddContent(0, "Component2 in global namespace");
+        }
+        #pragma warning restore 1998
+    }
+
+#pragma warning restore 1591
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component3_razor.g.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component3_razor.g.cs
new file mode 100644
index 00000000000..86097fd0f14
--- /dev/null
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Component3_razor.g.cs
@@ -0,0 +1,27 @@
+#pragma checksum "Component3.razor" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "4319ac545b421bebcac37ee05f6e0c730be31183"
+// <auto-generated/>
+#pragma warning disable 1591
+
+    #line default
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    #line default
+    #line hidden
+    #nullable restore
+    public partial class Component3 : global::Microsoft.AspNetCore.Components.ComponentBase
+    #nullable disable
+    {
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __builder.AddMarkupContent(0, "Component3 in global namespace\r\n");
+            __builder.OpenComponent<global::Shared.Component1>(1);
+            __builder.CloseComponent();
+        }
+        #pragma warning restore 1998
+    }
+
+#pragma warning restore 1591
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Shared_Component1_razor.g.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Shared_Component1_razor.g.cs
new file mode 100644
index 00000000000..50c24cb9cf4
--- /dev/null
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Shared_Component1_razor.g.cs
@@ -0,0 +1,31 @@
+#pragma checksum "Shared/Component1.razor" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "5d435cdce1d8978f1f0ffc5697761e2795ae0c94"
+// <auto-generated/>
+#pragma warning disable 1591
+namespace Shared
+{
+    #line default
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    #line default
+    #line hidden
+    #nullable restore
+    public partial class Component1 : global::Microsoft.AspNetCore.Components.ComponentBase
+    #nullable disable
+    {
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __builder.AddMarkupContent(0, "Component1 in Shared namespace\r\n");
+            __builder.OpenComponent<global::Component2>(1);
+            __builder.CloseComponent();
+            __builder.AddMarkupContent(2, "\r\n");
+            __builder.OpenComponent<global::Component4>(3);
+            __builder.CloseComponent();
+        }
+        #pragma warning restore 1998
+    }
+}
+#pragma warning restore 1591
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index.html b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index.html
new file mode 100644
index 00000000000..6a743889b83
--- /dev/null
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index.html
@@ -0,0 +1,6 @@
+Component1 in Shared namespace
+Component2 in global namespace
+
+Component3 in global namespace
+Component1 in Shared namespace
+Component2 in global namespace
diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs
new file mode 100644
index 00000000000..89b369f3cb2
--- /dev/null
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs
@@ -0,0 +1,65 @@
+#pragma checksum "Views/Home/Index.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "21502796fc325aa643d43afcd2ba3c6ad52ad693"
+// <auto-generated/>
+#pragma warning disable 1591
+[assembly: global::Microsoft.AspNetCore.Razor.Hosting.RazorCompiledItemAttribute(typeof(AspNetCoreGeneratedDocument.Views_Home_Index), @"mvc.1.0.view", @"/Views/Home/Index.cshtml")]
+namespace AspNetCoreGeneratedDocument
+{
+    #line default
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Mvc;
+    using global::Microsoft.AspNetCore.Mvc.Rendering;
+    using global::Microsoft.AspNetCore.Mvc.ViewFeatures;
+    #line default
+    #line hidden
+    [global::Microsoft.AspNetCore.Razor.Hosting.RazorCompiledItemMetadataAttribute("Identifier", "/Views/Home/Index.cshtml")]
+    [global::System.Runtime.CompilerServices.CreateNewOnMetadataUpdateAttribute]
+    #nullable restore
+    internal sealed class Views_Home_Index : global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<dynamic>
+    #nullable disable
+    {
+        #pragma warning disable 1998
+        public async override global::System.Threading.Tasks.Task ExecuteAsync()
+        {
+#nullable restore
+#line (1,3)-(1,72) 6 "Views/Home/Index.cshtml"
+Write(await Html.RenderComponentAsync<Shared.Component1>(RenderMode.Static));
+
+#line default
+#line hidden
+#nullable disable
+            WriteLiteral("\r\n");
+#nullable restore
+#line (2,3)-(2,65) 6 "Views/Home/Index.cshtml"
+Write(await Html.RenderComponentAsync<Component3>(RenderMode.Static));
+
+#line default
+#line hidden
+#nullable disable
+        }
+        #pragma warning restore 1998
+        #nullable restore
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.ViewFeatures.IModelExpressionProvider ModelExpressionProvider { get; private set; } = default!;
+        #nullable disable
+        #nullable restore
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.IUrlHelper Url { get; private set; } = default!;
+        #nullable disable
+        #nullable restore
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.IViewComponentHelper Component { get; private set; } = default!;
+        #nullable disable
+        #nullable restore
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.Rendering.IJsonHelper Json { get; private set; } = default!;
+        #nullable disable
+        #nullable restore
+        [global::Microsoft.AspNetCore.Mvc.Razor.Internal.RazorInjectAttribute]
+        public global::Microsoft.AspNetCore.Mvc.Rendering.IHtmlHelper<dynamic> Html { get; private set; } = default!;
+        #nullable disable
+    }
+}
+#pragma warning restore 1591

From 9de3c1751e33a86c142fafc812966dfa1d6b93ed Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 13 Mar 2024 16:13:28 +0100
Subject: [PATCH 02/11] Update existing tests

---
 .../BasicComponent_DesignTime.codegen.cs          |  2 +-
 .../BasicComponent_DesignTime.ir.txt              |  2 +-
 .../BasicComponent_DesignTime.mappings.txt        |  8 ++++----
 .../BasicComponent_Runtime.codegen.cs             |  2 +-
 .../BasicComponent_Runtime.ir.txt                 |  2 +-
 .../test/Extensions/MetadataAttributePassTest.cs  | 15 ++++++++++++++-
 .../Semantic/SemanticTokensTest.cs                |  2 +-
 7 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs
index 9b650e45a03..3c0217594f1 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs
@@ -11,7 +11,7 @@ namespace __GeneratedComponent
     #line default
     #line hidden
     #nullable restore
-    public partial class AspNetCore_3708c9fcd2e1ecb6cbaba92bcc60927f830690f42092c4aa1a7275c2f37020fd : global::Microsoft.AspNetCore.Components.ComponentBase, IDisposable
+    public partial class BasicComponent : global::Microsoft.AspNetCore.Components.ComponentBase, IDisposable
     #nullable disable
     {
         #pragma warning disable 219
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt
index 5db67ba568f..175ad5e9ef0 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt
@@ -5,7 +5,7 @@
         UsingDirective - (67:2,1 [25] ) - global::System.Linq
         UsingDirective - (95:3,1 [36] ) - global::System.Threading.Tasks
         UsingDirective - (134:4,1 [45] ) - global::Microsoft.AspNetCore.Components
-        ClassDeclaration -  - public partial - AspNetCore_3708c9fcd2e1ecb6cbaba92bcc60927f830690f42092c4aa1a7275c2f37020fd - global::Microsoft.AspNetCore.Components.ComponentBase - IDisposable
+        ClassDeclaration -  - public partial - BasicComponent - global::Microsoft.AspNetCore.Components.ComponentBase - IDisposable
             DesignTimeDirective - 
                 DirectiveToken - (12:0,12 [11] BasicComponent.cshtml) - IDisposable
             CSharpCode - 
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt
index 87aaee7e725..89528c26f47 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt
@@ -1,23 +1,23 @@
 Source Location: (12:0,12 [11] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |IDisposable|
-Generated Location: (813:21,0 [11] )
+Generated Location: (752:21,0 [11] )
 |IDisposable|
 
 Source Location: (38:1,13 [15] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |this.ToString()|
-Generated Location: (1413:39,13 [15] )
+Generated Location: (1352:39,13 [15] )
 |this.ToString()|
 
 Source Location: (79:3,5 [29] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |string.Format("{0}", "Hello")|
-Generated Location: (1610:47,6 [29] )
+Generated Location: (1549:47,6 [29] )
 |string.Format("{0}", "Hello")|
 
 Source Location: (132:6,12 [37] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |
     void IDisposable.Dispose(){ }
 |
-Generated Location: (1862:56,12 [37] )
+Generated Location: (1801:56,12 [37] )
 |
     void IDisposable.Dispose(){ }
 |
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs
index 3632868a85d..31290c3e8a2 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs
@@ -12,7 +12,7 @@ namespace __GeneratedComponent
     #line default
     #line hidden
     #nullable restore
-    public partial class AspNetCore_3708c9fcd2e1ecb6cbaba92bcc60927f830690f42092c4aa1a7275c2f37020fd : global::Microsoft.AspNetCore.Components.ComponentBase, IDisposable
+    public partial class BasicComponent : global::Microsoft.AspNetCore.Components.ComponentBase, IDisposable
     #nullable disable
     {
         #pragma warning disable 1998
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt
index b6e6405ae15..4b535da09e5 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt
@@ -5,7 +5,7 @@
         UsingDirective - (67:2,1 [27] ) - global::System.Linq
         UsingDirective - (95:3,1 [38] ) - global::System.Threading.Tasks
         UsingDirective - (134:4,1 [45] ) - global::Microsoft.AspNetCore.Components
-        ClassDeclaration -  - public partial - AspNetCore_3708c9fcd2e1ecb6cbaba92bcc60927f830690f42092c4aa1a7275c2f37020fd - global::Microsoft.AspNetCore.Components.ComponentBase - IDisposable
+        ClassDeclaration -  - public partial - BasicComponent - global::Microsoft.AspNetCore.Components.ComponentBase - IDisposable
             MethodDeclaration -  - protected override - void - BuildRenderTree
                 MarkupElement - (25:1,0 [91] BasicComponent.cshtml) - div
                     HtmlAttribute - (29:1,4 [25] BasicComponent.cshtml) -  class=" - "
diff --git a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/Extensions/MetadataAttributePassTest.cs b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/Extensions/MetadataAttributePassTest.cs
index 2f09ba6967c..7891fc15c81 100644
--- a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/Extensions/MetadataAttributePassTest.cs
+++ b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/Extensions/MetadataAttributePassTest.cs
@@ -133,7 +133,20 @@ public void Execute_NoNamespaceSet_Noops()
         pass.Execute(codeDocument, irDocument);
 
         // Assert
-        SingleChild<NamespaceDeclarationIntermediateNode>(irDocument);
+        Assert.Equal(2, irDocument.Children.Count);
+
+        var item = Assert.IsType<RazorCompiledItemAttributeIntermediateNode>(irDocument.Children[0]);
+        Assert.Equal("/test.cshtml", item.Identifier);
+        Assert.Equal("test", item.Kind);
+        Assert.Equal("Test", item.TypeName);
+
+        Assert.Equal(2, @namespace.Children.Count);
+        var checksum = Assert.IsType<RazorSourceChecksumAttributeIntermediateNode>(@namespace.Children[0]);
+        Assert.Equal(CodeAnalysis.Text.SourceHashAlgorithm.Sha256, checksum.ChecksumAlgorithm);
+        Assert.Equal("/test.cshtml", checksum.Identifier);
+
+        var foundClass = Assert.IsType<ClassDeclarationIntermediateNode>(@namespace.Children[1]);
+        Assert.Equal("Test", foundClass.ClassName);
     }
 
     [Fact]
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Semantic/SemanticTokensTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Semantic/SemanticTokensTest.cs
index 1990c760e04..ced9191d2f6 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Semantic/SemanticTokensTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Semantic/SemanticTokensTest.cs
@@ -888,7 +888,7 @@ public void GetMappedCSharpRanges_MinimalRangeVsSmallDisjointRanges_DisjointRang
         else
         {
             // Note that the expected lengths are different on Windows vs. Unix.
-            var expectedCsharpRangeLength = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? 1016 : 982;
+            var expectedCsharpRangeLength = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? 945 : 911;
             Assert.True(codeDocument.TryGetMinimalCSharpRange(razorRange, out var csharpRange));
             var textSpan = csharpRange.ToTextSpan(csharpSourceText);
             Assert.Equal(expectedCsharpRangeLength, textSpan.Length);

From acf120886310f7b1310cf45e11c21228ca0be992 Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Tue, 19 Mar 2024 15:27:51 +0100
Subject: [PATCH 03/11] Fixup baseline

---
 .../EmptyRootNamespace/Views_Home_Index_cshtml.g.cs  | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs
index 89b369f3cb2..d9e020b6a81 100644
--- a/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs
+++ b/src/Compiler/test/Microsoft.NET.Sdk.Razor.SourceGenerators.Tests/TestFiles/RazorSourceGeneratorComponentTests/EmptyRootNamespace/Views_Home_Index_cshtml.g.cs
@@ -23,21 +23,25 @@ internal sealed class Views_Home_Index : global::Microsoft.AspNetCore.Mvc.Razor.
         #pragma warning disable 1998
         public async override global::System.Threading.Tasks.Task ExecuteAsync()
         {
+            Write(
 #nullable restore
-#line (1,3)-(1,72) 6 "Views/Home/Index.cshtml"
-Write(await Html.RenderComponentAsync<Shared.Component1>(RenderMode.Static));
+#line (1,3)-(1,72) "Views/Home/Index.cshtml"
+await Html.RenderComponentAsync<Shared.Component1>(RenderMode.Static)
 
 #line default
 #line hidden
 #nullable disable
+            );
             WriteLiteral("\r\n");
+            Write(
 #nullable restore
-#line (2,3)-(2,65) 6 "Views/Home/Index.cshtml"
-Write(await Html.RenderComponentAsync<Component3>(RenderMode.Static));
+#line (2,3)-(2,65) "Views/Home/Index.cshtml"
+await Html.RenderComponentAsync<Component3>(RenderMode.Static)
 
 #line default
 #line hidden
 #nullable disable
+            );
         }
         #pragma warning restore 1998
         #nullable restore

From a7713a7f445c6d96110e91476b0f8f97e640a6de Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Tue, 19 Mar 2024 15:59:24 +0100
Subject: [PATCH 04/11] Test formatting of component in global namespace

---
 .../Formatting_NetFx/FormattingTestBase.cs         | 14 +++++++++-----
 .../Formatting_NetFx/RazorFormattingTest.cs        |  7 ++++---
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
index e1d0b81376b..276b9472349 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Immutable;
+using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -44,7 +45,8 @@ private protected async Task RunFormattingTestAsync(
         string? fileKind = null,
         ImmutableArray<TagHelperDescriptor> tagHelpers = default,
         bool allowDiagnostics = false,
-        RazorLSPOptions? razorLSPOptions = null)
+        RazorLSPOptions? razorLSPOptions = null,
+        bool inGlobalNamespace = false)
     {
         // Arrange
         fileKind ??= FileKinds.Component;
@@ -59,7 +61,7 @@ private protected async Task RunFormattingTestAsync(
 
         var path = "file:///path/to/Document." + fileKind;
         var uri = new Uri(path);
-        var (codeDocument, documentSnapshot) = CreateCodeDocumentAndSnapshot(source, uri.AbsolutePath, tagHelpers, fileKind, allowDiagnostics);
+        var (codeDocument, documentSnapshot) = CreateCodeDocumentAndSnapshot(source, uri.AbsolutePath, tagHelpers, fileKind, allowDiagnostics, inGlobalNamespace);
         var options = new FormattingOptions()
         {
             TabSize = tabSize,
@@ -218,7 +220,7 @@ private static SourceText ApplyEdits(SourceText source, TextEdit[] edits)
         return source.WithChanges(changes);
     }
 
-    private static (RazorCodeDocument, IDocumentSnapshot) CreateCodeDocumentAndSnapshot(SourceText text, string path, ImmutableArray<TagHelperDescriptor> tagHelpers = default, string? fileKind = default, bool allowDiagnostics = false)
+    private static (RazorCodeDocument, IDocumentSnapshot) CreateCodeDocumentAndSnapshot(SourceText text, string path, ImmutableArray<TagHelperDescriptor> tagHelpers = default, string? fileKind = default, bool allowDiagnostics = false, bool inGlobalNamespace = false)
     {
         fileKind ??= FileKinds.Component;
         tagHelpers = tagHelpers.NullToEmpty();
@@ -228,7 +230,9 @@ private static (RazorCodeDocument, IDocumentSnapshot) CreateCodeDocumentAndSnaps
             tagHelpers = tagHelpers.AddRange(RazorTestResources.BlazorServerAppTagHelpers);
         }
 
-        var sourceDocument = RazorSourceDocument.Create(text, RazorSourceDocumentProperties.Create(path, path));
+        var sourceDocument = RazorSourceDocument.Create(text, RazorSourceDocumentProperties.Create(
+            filePath: path,
+            relativePath: inGlobalNamespace ? Path.GetFileName(path) : path));
 
         const string DefaultImports = """
                 @using BlazorApp1
@@ -256,7 +260,7 @@ @using Microsoft.AspNetCore.Components.Web
 
         var projectEngine = RazorProjectEngine.Create(builder =>
         {
-            builder.SetRootNamespace("Test");
+            builder.SetRootNamespace(inGlobalNamespace ? string.Empty : "Test");
             builder.Features.Add(new DefaultTypeNameFeature());
             RazorExtensions.Register(builder);
         });
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs
index b2cbdd1c2b1..a9e5754d120 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs
@@ -77,8 +77,8 @@ private void IncrementCount()
                     """);
     }
 
-    [Fact]
-    public async Task CodeBlock_IndentedBlock_MaintainsIndent()
+    [Theory, CombinatorialData]
+    public async Task CodeBlock_IndentedBlock_MaintainsIndent(bool inGlobalNamespace)
     {
         await RunFormattingTestAsync(
             input: """
@@ -106,7 +106,8 @@ private void IncrementCount()
                             }
                         }
                     </boo>
-                    """);
+                    """,
+            inGlobalNamespace: inGlobalNamespace);
     }
 
     [Fact]

From e9f30fbb3436cd7c9e0f0d8d1494f2c1510d6e4a Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 20 Mar 2024 12:06:34 +0100
Subject: [PATCH 05/11] Add design-time codegen test

---
 .../ComponentCodeGenerationTestBase.cs        | 33 ++++++++++++
 .../TestComponent.codegen.cs                  | 50 +++++++++++++++++++
 .../EmptyRootNamespace/TestComponent.ir.txt   | 25 ++++++++++
 .../TestComponent.codegen.cs                  | 29 +++++++++++
 .../EmptyRootNamespace/TestComponent.ir.txt   | 14 ++++++
 .../RazorIntegrationTestBase.cs               |  2 +-
 6 files changed, 152 insertions(+), 1 deletion(-)
 create mode 100644 src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs
 create mode 100644 src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt
 create mode 100644 src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs
 create mode 100644 src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt

diff --git a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/IntegrationTests/ComponentCodeGenerationTestBase.cs b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/IntegrationTests/ComponentCodeGenerationTestBase.cs
index 953a7b47924..aa3b5d50ae2 100644
--- a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/IntegrationTests/ComponentCodeGenerationTestBase.cs
+++ b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/IntegrationTests/ComponentCodeGenerationTestBase.cs
@@ -9633,6 +9633,39 @@ @preservewhitespace false
 
     #endregion
 
+    #region Namespace
+
+    [IntegrationTestFact]
+    public void EmptyRootNamespace()
+    {
+        DefaultRootNamespace = string.Empty;
+
+        AdditionalSyntaxTrees.Add(Parse("""
+            using Microsoft.AspNetCore.Components;
+            public class Component1 : ComponentBase { }
+            namespace Shared
+            {
+                public class Component2 : ComponentBase { }
+            }
+            class C
+            {
+                void M1(TestComponent t) { }
+                void M2(global::TestComponent t) { }
+            }
+            """));
+        var generated = CompileToCSharp("""
+            <h1>Generated</h1>
+            <Component1 />
+            <Shared.Component2 />
+            """);
+
+        AssertDocumentNodeMatchesBaseline(generated.CodeDocument);
+        AssertCSharpDocumentMatchesBaseline(generated.CodeDocument);
+        CompileToAssembly(generated);
+    }
+
+    #endregion
+
     #region "CSS scoping"
     [IntegrationTestFact]
     public void Component_WithCssScope()
diff --git a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs
new file mode 100644
index 00000000000..3f92a5da05f
--- /dev/null
+++ b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs
@@ -0,0 +1,50 @@
+// <auto-generated/>
+#pragma warning disable 1591
+
+    #line default
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    #line default
+    #line hidden
+    #nullable restore
+    public partial class TestComponent : global::Microsoft.AspNetCore.Components.ComponentBase
+    #nullable disable
+    {
+        #pragma warning disable 219
+        private void __RazorDirectiveTokenHelpers__() {
+        }
+        #pragma warning restore 219
+        #pragma warning disable 0414
+        private static object __o = null;
+        #pragma warning restore 0414
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __builder.AddAttribute(-1, "ChildContent", (global::Microsoft.AspNetCore.Components.RenderFragment)((__builder2) => {
+            }
+            ));
+#nullable restore
+#line 2 "x:\dir\subdir\Test\TestComponent.cshtml"
+__o = typeof(global::Component1);
+
+#line default
+#line hidden
+#nullable disable
+            __builder.AddAttribute(-1, "ChildContent", (global::Microsoft.AspNetCore.Components.RenderFragment)((__builder2) => {
+            }
+            ));
+#nullable restore
+#line 3 "x:\dir\subdir\Test\TestComponent.cshtml"
+__o = typeof(global::Shared.Component2);
+
+#line default
+#line hidden
+#nullable disable
+        }
+        #pragma warning restore 1998
+    }
+
+#pragma warning restore 1591
diff --git a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt
new file mode 100644
index 00000000000..1b0c909f635
--- /dev/null
+++ b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentDesignTimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt
@@ -0,0 +1,25 @@
+Document - 
+    NamespaceDeclaration -  - 
+        UsingDirective - (3:1,1 [20] ) - global::System
+        UsingDirective - (26:2,1 [40] ) - global::System.Collections.Generic
+        UsingDirective - (69:3,1 [25] ) - global::System.Linq
+        UsingDirective - (97:4,1 [36] ) - global::System.Threading.Tasks
+        UsingDirective - (136:5,1 [45] ) - global::Microsoft.AspNetCore.Components
+        ClassDeclaration -  - public partial - TestComponent - global::Microsoft.AspNetCore.Components.ComponentBase - 
+            DesignTimeDirective - 
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning disable 0414
+            CSharpCode - 
+                IntermediateToken -  - CSharp - private static object __o = null;
+            CSharpCode - 
+                IntermediateToken -  - CSharp - #pragma warning restore 0414
+            MethodDeclaration -  - protected override - void - BuildRenderTree
+                MarkupElement - (0:0,0 [18] x:\dir\subdir\Test\TestComponent.cshtml) - h1
+                    HtmlContent - (4:0,4 [9] x:\dir\subdir\Test\TestComponent.cshtml)
+                        LazyIntermediateToken - (4:0,4 [9] x:\dir\subdir\Test\TestComponent.cshtml) - Html - Generated
+                HtmlContent - (18:0,18 [2] x:\dir\subdir\Test\TestComponent.cshtml)
+                    LazyIntermediateToken - (18:0,18 [2] x:\dir\subdir\Test\TestComponent.cshtml) - Html - \n
+                Component - (20:1,0 [14] x:\dir\subdir\Test\TestComponent.cshtml) - Component1
+                HtmlContent - (34:1,14 [2] x:\dir\subdir\Test\TestComponent.cshtml)
+                    LazyIntermediateToken - (34:1,14 [2] x:\dir\subdir\Test\TestComponent.cshtml) - Html - \n
+                Component - (36:2,0 [21] x:\dir\subdir\Test\TestComponent.cshtml) - Shared.Component2
diff --git a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs
new file mode 100644
index 00000000000..f5b2f59cde3
--- /dev/null
+++ b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.codegen.cs
@@ -0,0 +1,29 @@
+// <auto-generated/>
+#pragma warning disable 1591
+
+    #line default
+    using global::System;
+    using global::System.Collections.Generic;
+    using global::System.Linq;
+    using global::System.Threading.Tasks;
+    using global::Microsoft.AspNetCore.Components;
+    #line default
+    #line hidden
+    #nullable restore
+    public partial class TestComponent : global::Microsoft.AspNetCore.Components.ComponentBase
+    #nullable disable
+    {
+        #pragma warning disable 1998
+        protected override void BuildRenderTree(global::Microsoft.AspNetCore.Components.Rendering.RenderTreeBuilder __builder)
+        {
+            __builder.AddMarkupContent(0, "<h1>Generated</h1>\r\n");
+            __builder.OpenComponent<global::Component1>(1);
+            __builder.CloseComponent();
+            __builder.AddMarkupContent(2, "\r\n");
+            __builder.OpenComponent<global::Shared.Component2>(3);
+            __builder.CloseComponent();
+        }
+        #pragma warning restore 1998
+    }
+
+#pragma warning restore 1591
diff --git a/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt
new file mode 100644
index 00000000000..4a3605d3f4d
--- /dev/null
+++ b/src/Compiler/Microsoft.AspNetCore.Razor.Language/test/TestFiles/IntegrationTests/ComponentRuntimeCodeGenerationTest/EmptyRootNamespace/TestComponent.ir.txt
@@ -0,0 +1,14 @@
+Document - 
+    NamespaceDeclaration -  - 
+        UsingDirective - (3:1,1 [22] ) - global::System
+        UsingDirective - (26:2,1 [42] ) - global::System.Collections.Generic
+        UsingDirective - (69:3,1 [27] ) - global::System.Linq
+        UsingDirective - (97:4,1 [38] ) - global::System.Threading.Tasks
+        UsingDirective - (136:5,1 [47] ) - global::Microsoft.AspNetCore.Components
+        ClassDeclaration -  - public partial - TestComponent - global::Microsoft.AspNetCore.Components.ComponentBase - 
+            MethodDeclaration -  - protected override - void - BuildRenderTree
+                MarkupBlock -  - <h1>Generated</h1>\n
+                Component - (20:1,0 [14] x:\dir\subdir\Test\TestComponent.cshtml) - Component1
+                HtmlContent - (34:1,14 [2] x:\dir\subdir\Test\TestComponent.cshtml)
+                    LazyIntermediateToken - (34:1,14 [2] x:\dir\subdir\Test\TestComponent.cshtml) - Html - \n
+                Component - (36:2,0 [21] x:\dir\subdir\Test\TestComponent.cshtml) - Shared.Component2
diff --git a/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/RazorIntegrationTestBase.cs b/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/RazorIntegrationTestBase.cs
index 3adedb73fb9..d0aa246c2a5 100644
--- a/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/RazorIntegrationTestBase.cs
+++ b/src/Shared/Microsoft.AspNetCore.Razor.Test.Common/Language/IntegrationTests/RazorIntegrationTestBase.cs
@@ -84,7 +84,7 @@ public RazorIntegrationTestBase()
 
     internal virtual RazorConfiguration Configuration { get; }
 
-    internal virtual string DefaultRootNamespace { get; }
+    internal string DefaultRootNamespace { get; set; }
 
     internal virtual string DefaultFileName { get; }
 

From 61ead073f8702ca5b8e34aa91d329b3d6ad6cfaf Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 20 Mar 2024 12:26:38 +0100
Subject: [PATCH 06/11] Automatically determine where empty root namespace is
 allowed

---
 .../BasicComponent_DesignTime.codegen.cs          |  2 +-
 .../BasicComponent_DesignTime.ir.txt              |  2 +-
 .../BasicComponent_DesignTime.mappings.txt        |  8 ++++----
 .../BasicComponent_Runtime.codegen.cs             |  2 +-
 .../BasicComponent_Runtime.ir.txt                 |  2 +-
 .../Components/ComponentDocumentClassifierPass.cs |  2 +-
 .../src/Language/RazorCodeDocumentExtensions.cs   | 15 +++++++--------
 7 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs
index 3c0217594f1..fcc8df2a724 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.codegen.cs
@@ -1,6 +1,6 @@
 // <auto-generated/>
 #pragma warning disable 1591
-namespace __GeneratedComponent
+namespace TestFiles.IntegrationTests.CodeGenerationIntegrationTest
 {
     #line default
     using global::System;
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt
index 175ad5e9ef0..6b8b55abf56 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.ir.txt
@@ -1,5 +1,5 @@
 Document - 
-    NamespaceDeclaration -  - __GeneratedComponent
+    NamespaceDeclaration -  - TestFiles.IntegrationTests.CodeGenerationIntegrationTest
         UsingDirective - (1:0,1 [20] ) - global::System
         UsingDirective - (24:1,1 [40] ) - global::System.Collections.Generic
         UsingDirective - (67:2,1 [25] ) - global::System.Linq
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt
index 89528c26f47..9981d0caf97 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_DesignTime.mappings.txt
@@ -1,23 +1,23 @@
 Source Location: (12:0,12 [11] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |IDisposable|
-Generated Location: (752:21,0 [11] )
+Generated Location: (788:21,0 [11] )
 |IDisposable|
 
 Source Location: (38:1,13 [15] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |this.ToString()|
-Generated Location: (1352:39,13 [15] )
+Generated Location: (1388:39,13 [15] )
 |this.ToString()|
 
 Source Location: (79:3,5 [29] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |string.Format("{0}", "Hello")|
-Generated Location: (1549:47,6 [29] )
+Generated Location: (1585:47,6 [29] )
 |string.Format("{0}", "Hello")|
 
 Source Location: (132:6,12 [37] TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml)
 |
     void IDisposable.Dispose(){ }
 |
-Generated Location: (1801:56,12 [37] )
+Generated Location: (1837:56,12 [37] )
 |
     void IDisposable.Dispose(){ }
 |
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs
index 1d1fed5ccf0..8becffde010 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.codegen.cs
@@ -1,7 +1,7 @@
 #pragma checksum "TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent.cshtml" "{8829d00f-11b8-4213-878b-770e8597ac16}" "3708c9fcd2e1ecb6cbaba92bcc60927f830690f42092c4aa1a7275c2f37020fd"
 // <auto-generated/>
 #pragma warning disable 1591
-namespace __GeneratedComponent
+namespace TestFiles.IntegrationTests.CodeGenerationIntegrationTest
 {
     #line default
     using global::System;
diff --git a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt
index 4b535da09e5..970d4c4e3c6 100644
--- a/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt
+++ b/src/Compiler/Microsoft.AspNetCore.Mvc.Razor.Extensions/test/TestFiles/IntegrationTests/CodeGenerationIntegrationTest/BasicComponent_Runtime.ir.txt
@@ -1,5 +1,5 @@
 Document - 
-    NamespaceDeclaration -  - __GeneratedComponent
+    NamespaceDeclaration -  - TestFiles.IntegrationTests.CodeGenerationIntegrationTest
         UsingDirective - (1:0,1 [22] ) - global::System
         UsingDirective - (24:1,1 [42] ) - global::System.Collections.Generic
         UsingDirective - (67:2,1 [27] ) - global::System.Linq
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs
index 13f258777f1..407cbf24cba 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Components/ComponentDocumentClassifierPass.cs
@@ -62,7 +62,7 @@ protected override void OnDocumentStructureCreated(
         ClassDeclarationIntermediateNode @class,
         MethodDeclarationIntermediateNode method)
     {
-        if (!codeDocument.TryComputeNamespace(fallbackToRootNamespace: true, allowEmptyRootNamespace: true, out var computedNamespace, out var computedNamespaceSpan))
+        if (!codeDocument.TryComputeNamespace(fallbackToRootNamespace: true, out var computedNamespace, out var computedNamespaceSpan))
         {
             computedNamespace = FallbackRootNamespace;
         }
diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs
index 43501a2ad78..2757ca9208f 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/RazorCodeDocumentExtensions.cs
@@ -304,14 +304,14 @@ public static bool TryComputeClassName(this RazorCodeDocument codeDocument, [Not
 #nullable disable
 
     public static bool TryComputeNamespace(this RazorCodeDocument document, bool fallbackToRootNamespace, out string @namespace)
-        => TryComputeNamespace(document, fallbackToRootNamespace: fallbackToRootNamespace, allowEmptyRootNamespace: false, out @namespace, out _);
+        => TryComputeNamespace(document, fallbackToRootNamespace, out @namespace, out _);
 
     // In general documents will have a relative path (relative to the project root).
     // We can only really compute a nice namespace when we know a relative path.
     //
     // However all kinds of thing are possible in tools. We shouldn't barf here if the document isn't
     // set up correctly.
-    internal static bool TryComputeNamespace(this RazorCodeDocument document, bool fallbackToRootNamespace, bool allowEmptyRootNamespace, out string @namespace, out SourceSpan? namespaceSpan)
+    public static bool TryComputeNamespace(this RazorCodeDocument document, bool fallbackToRootNamespace, out string @namespace, out SourceSpan? namespaceSpan)
     {
         if (document == null)
         {
@@ -325,7 +325,7 @@ internal static bool TryComputeNamespace(this RazorCodeDocument document, bool f
         }
         else
         {
-            var result = TryComputeNamespaceCore(document, fallbackToRootNamespace: fallbackToRootNamespace, allowEmptyRootNamespace: allowEmptyRootNamespace, out @namespace, out namespaceSpan);
+            var result = TryComputeNamespaceCore(document, fallbackToRootNamespace, out @namespace, out namespaceSpan);
             if (result)
             {
                 document.Items[NamespaceKey] = (@namespace, namespaceSpan);
@@ -336,14 +336,14 @@ internal static bool TryComputeNamespace(this RazorCodeDocument document, bool f
 #if DEBUG
         // In debug mode, even if we're cached, lets take the hit to run this again and make sure the cached value is correct.
         // This is to help us find issues with caching logic during development.
-        var validateResult = TryComputeNamespaceCore(document, fallbackToRootNamespace: fallbackToRootNamespace, allowEmptyRootNamespace: allowEmptyRootNamespace, out var validateNamespace, out _);
+        var validateResult = TryComputeNamespaceCore(document, fallbackToRootNamespace, out var validateNamespace, out _);
         Debug.Assert(validateResult, "We couldn't compute the namespace, but have a cached value, so something has gone wrong");
         Debug.Assert(validateNamespace == @namespace, $"We cached a namespace of {@namespace} but calculated that it should be {validateNamespace}");
 #endif
 
         return true;
 
-        bool TryComputeNamespaceCore(RazorCodeDocument document, bool fallbackToRootNamespace, bool allowEmptyRootNamespace, out string @namespace, out SourceSpan? namespaceSpan)
+        bool TryComputeNamespaceCore(RazorCodeDocument document, bool fallbackToRootNamespace, out string @namespace, out SourceSpan? namespaceSpan)
         {
             var filePath = document.Source.FilePath;
             if (filePath == null || document.Source.RelativePath == null || filePath.Length < document.Source.RelativePath.Length)
@@ -409,9 +409,8 @@ bool TryComputeNamespaceCore(RazorCodeDocument document, bool fallbackToRootName
                 baseNamespace = options?.RootNamespace;
                 appendSuffix = true;
 
-                // null means RootNamespace wasn't set yet, so we fail for now, tooling seems to rely on this
-                if (baseNamespace is null ||
-                    (!allowEmptyRootNamespace && string.IsNullOrEmpty(baseNamespace)))
+                // Empty RootNamespace is allowed only in components.
+                if (!FileKinds.IsComponent(document.GetFileKind()) && string.IsNullOrEmpty(baseNamespace))
                 {
                     @namespace = null;
                     return false;

From d5eeae831a3ac9564d0f5be8070d77e759d3858a Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 20 Mar 2024 15:00:58 +0100
Subject: [PATCH 07/11] Fixup tooling

---
 .../Definition/DefinitionEndpoint.cs          | 20 +++++++++++++++----
 .../CodeActionEndToEndTest.NetFx.cs           |  6 +-----
 ...nentAccessibilityCodeActionProviderTest.cs |  5 +++++
 .../LanguageServer/LanguageServerTestBase.cs  | 12 +++++++++--
 4 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Definition/DefinitionEndpoint.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Definition/DefinitionEndpoint.cs
index 1887e9df5cf..28f014bcd83 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Definition/DefinitionEndpoint.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Definition/DefinitionEndpoint.cs
@@ -277,9 +277,7 @@ private async Task<Range> GetNavigateRangeAsync(IDocumentSnapshot documentSnapsh
         // Since we know how the compiler generates the C# source we can be a little specific here, and avoid
         // long tree walks. If the compiler ever changes how they generate their code, the tests for this will break
         // so we'll know about it.
-        if (root is CompilationUnitSyntax compilationUnit &&
-            compilationUnit.Members[0] is NamespaceDeclarationSyntax namespaceDeclaration &&
-            namespaceDeclaration.Members[0] is ClassDeclarationSyntax classDeclaration)
+        if (GetClassDeclaration(root) is { } classDeclaration)
         {
             var property = classDeclaration
                 .Members
@@ -303,8 +301,22 @@ compilationUnit.Members[0] is NamespaceDeclarationSyntax namespaceDeclaration &&
             logger.LogInformation("Property found but couldn't map its location.");
         }
 
-        logger.LogInformation("Generated C# was not in expected shape (CompilationUnit -> Namespace -> Class)");
+        logger.LogInformation("Generated C# was not in expected shape (CompilationUnit [-> Namespace] -> Class)");
 
         return null;
+
+        static ClassDeclarationSyntax? GetClassDeclaration(CodeAnalysis.SyntaxNode root)
+        {
+            return root switch
+            {
+                CompilationUnitSyntax unit => unit switch
+                {
+                    { Members: [NamespaceDeclarationSyntax { Members: [ClassDeclarationSyntax c, ..] }, ..] } => c,
+                    { Members: [ClassDeclarationSyntax c, ..] } => c,
+                    _ => null,
+                },
+                _ => null,
+            };
+        }
     }
 }
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs
index 29329496b27..4121999b00e 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CodeActionEndToEndTest.NetFx.cs
@@ -1017,11 +1017,7 @@ private async Task ValidateCodeBehindFileAsync(
         var diagnostics = new[] { new Diagnostic() { Code = "CS0103", Message = "The name 'DoesNotExist' does not exist in the current context" } };
 
         TestFileMarkupParser.GetSpan(input, out input, out var textSpan);
-        var codeDocument = CreateCodeDocument(input, filePath: razorFilePath);
-        codeDocument.SetCodeGenerationOptions(RazorCodeGenerationOptions.Create(o =>
-        {
-            o.RootNamespace = "Test";
-        }));
+        var codeDocument = CreateCodeDocument(input, filePath: razorFilePath, rootNamespace: "Test");
         var razorSourceText = codeDocument.GetSourceText();
         var uri = new Uri(razorFilePath);
         var languageServer = await CreateLanguageServerAsync(codeDocument, razorFilePath);
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/Razor/ComponentAccessibilityCodeActionProviderTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/Razor/ComponentAccessibilityCodeActionProviderTest.cs
index 980001cae92..d2a6f11c4dd 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/Razor/ComponentAccessibilityCodeActionProviderTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/Razor/ComponentAccessibilityCodeActionProviderTest.cs
@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Threading;
 using System.Threading.Tasks;
@@ -444,16 +445,20 @@ private static RazorCodeActionContext CreateRazorCodeActionContext(VSCodeActionP
         var shortComponent = TagHelperDescriptorBuilder.Create(ComponentMetadata.Component.TagHelperKind, "Fully.Qualified.Component", "TestAssembly");
         shortComponent.CaseSensitive = true;
         shortComponent.TagMatchingRule(rule => rule.TagName = "Component");
+        shortComponent.SetMetadata(CommonMetadata.TypeNamespace("Fully.Qualified"));
         var fullyQualifiedComponent = TagHelperDescriptorBuilder.Create(ComponentMetadata.Component.TagHelperKind, "Fully.Qualified.Component", "TestAssembly");
         fullyQualifiedComponent.CaseSensitive = true;
         fullyQualifiedComponent.TagMatchingRule(rule => rule.TagName = "Fully.Qualified.Component");
+        fullyQualifiedComponent.SetMetadata(CommonMetadata.TypeNamespace("Fully.Qualified"));
 
         var shortGenericComponent = TagHelperDescriptorBuilder.Create(ComponentMetadata.Component.TagHelperKind, "Fully.Qualified.GenericComponent<T>", "TestAssembly");
         shortGenericComponent.CaseSensitive = true;
         shortGenericComponent.TagMatchingRule(rule => rule.TagName = "GenericComponent");
+        shortGenericComponent.SetMetadata(CommonMetadata.TypeNamespace("Fully.Qualified"));
         var fullyQualifiedGenericComponent = TagHelperDescriptorBuilder.Create(ComponentMetadata.Component.TagHelperKind, "Fully.Qualified.GenericComponent<T>", "TestAssembly");
         fullyQualifiedGenericComponent.CaseSensitive = true;
         fullyQualifiedGenericComponent.TagMatchingRule(rule => rule.TagName = "Fully.Qualified.GenericComponent");
+        fullyQualifiedGenericComponent.SetMetadata(CommonMetadata.TypeNamespace("Fully.Qualified"));
 
         var tagHelpers = ImmutableArray.Create(shortComponent.Build(), fullyQualifiedComponent.Build(), shortGenericComponent.Build(), fullyQualifiedGenericComponent.Build());
 
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/LanguageServerTestBase.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/LanguageServerTestBase.cs
index e5082bf1f02..891c66e4513 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/LanguageServerTestBase.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.Test.Common.Tooling/LanguageServer/LanguageServerTestBase.cs
@@ -69,7 +69,7 @@ internal RazorRequestContext CreateRazorRequestContext(VersionedDocumentContext?
         return requestContext;
     }
 
-    protected static RazorCodeDocument CreateCodeDocument(string text, ImmutableArray<TagHelperDescriptor> tagHelpers = default, string? filePath = null)
+    protected static RazorCodeDocument CreateCodeDocument(string text, ImmutableArray<TagHelperDescriptor> tagHelpers = default, string? filePath = null, string? rootNamespace = null)
     {
         filePath ??= "test.cshtml";
 
@@ -82,7 +82,15 @@ protected static RazorCodeDocument CreateCodeDocument(string text, ImmutableArra
         }
 
         var sourceDocument = TestRazorSourceDocument.Create(text, filePath: filePath, relativePath: filePath);
-        var projectEngine = RazorProjectEngine.Create(RazorExtensions.Register);
+        var projectEngine = RazorProjectEngine.Create(b =>
+        {
+            if (rootNamespace != null)
+            {
+                b.SetRootNamespace(rootNamespace);
+            }
+
+            RazorExtensions.Register(b);
+        });
         var importDocumentName = fileKind == FileKinds.Legacy ? "_ViewImports.cshtml" : "_Imports.razor";
         var defaultImportDocument = TestRazorSourceDocument.Create(
             """

From 7f6c75d9b6b8913a723556c0878fdcbed79e2c21 Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 20 Mar 2024 15:37:47 +0100
Subject: [PATCH 08/11] Test more formatting in global namespace

---
 .../CSharpStatementBlockOnTypeFormattingTest.cs    | 14 ++++++++------
 .../Formatting_NetFx/FormattingTestBase.cs         | 10 ++++++----
 .../Formatting_NetFx/RazorFormattingTest.cs        |  7 ++++---
 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/CSharpStatementBlockOnTypeFormattingTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/CSharpStatementBlockOnTypeFormattingTest.cs
index a62081970f5..9e769c37366 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/CSharpStatementBlockOnTypeFormattingTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/CSharpStatementBlockOnTypeFormattingTest.cs
@@ -28,8 +28,8 @@ await RunOnTypeFormattingTestAsync(
             triggerCharacter: '}');
     }
 
-    [Fact]
-    public async Task CloseCurly_IfBlock_MultiLineAsync()
+    [Theory, CombinatorialData]
+    public async Task CloseCurly_IfBlock_MultiLineAsync(bool inGlobalNamespace)
     {
         await RunOnTypeFormattingTestAsync(
             input: """
@@ -46,11 +46,12 @@ await RunOnTypeFormattingTestAsync(
                         }
                     }
                     """,
-            triggerCharacter: '}');
+            triggerCharacter: '}',
+            inGlobalNamespace: inGlobalNamespace);
     }
 
-    [Fact]
-    public async Task CloseCurly_MultipleStatementBlocksAsync()
+    [Theory, CombinatorialData]
+    public async Task CloseCurly_MultipleStatementBlocksAsync(bool inGlobalNamespace)
     {
         await RunOnTypeFormattingTestAsync(
             input: """
@@ -79,7 +80,8 @@ await RunOnTypeFormattingTestAsync(
                         }
                     }
                     """,
-            triggerCharacter: '}');
+            triggerCharacter: '}',
+            inGlobalNamespace: inGlobalNamespace);
     }
 
     [Fact]
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
index 276b9472349..05651a80c7a 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
@@ -96,7 +96,8 @@ private protected async Task RunOnTypeFormattingTestAsync(
         bool insertSpaces = true,
         string? fileKind = null,
         int? expectedChangedLines = null,
-        RazorLSPOptions? razorLSPOptions = null)
+        RazorLSPOptions? razorLSPOptions = null,
+        bool inGlobalNamespace = false)
     {
         // Arrange
         fileKind ??= FileKinds.Component;
@@ -106,7 +107,7 @@ private protected async Task RunOnTypeFormattingTestAsync(
         var razorSourceText = SourceText.From(input);
         var path = "file:///path/to/Document.razor";
         var uri = new Uri(path);
-        var (codeDocument, documentSnapshot) = CreateCodeDocumentAndSnapshot(razorSourceText, uri.AbsolutePath, fileKind: fileKind);
+        var (codeDocument, documentSnapshot) = CreateCodeDocumentAndSnapshot(razorSourceText, uri.AbsolutePath, fileKind: fileKind, inGlobalNamespace: inGlobalNamespace);
 
         var filePathService = new FilePathService(TestLanguageServerFeatureOptions.Instance);
         var mappingService = new RazorDocumentMappingService(
@@ -153,7 +154,8 @@ protected async Task RunCodeActionFormattingTestAsync(
         string expected,
         int tabSize = 4,
         bool insertSpaces = true,
-        string? fileKind = null)
+        string? fileKind = null,
+        bool inGlobalNamespace = false)
     {
         if (codeActionEdits is null)
         {
@@ -168,7 +170,7 @@ protected async Task RunCodeActionFormattingTestAsync(
         var razorSourceText = SourceText.From(input);
         var path = "file:///path/to/Document.razor";
         var uri = new Uri(path);
-        var (codeDocument, documentSnapshot) = CreateCodeDocumentAndSnapshot(razorSourceText, uri.AbsolutePath, fileKind: fileKind);
+        var (codeDocument, documentSnapshot) = CreateCodeDocumentAndSnapshot(razorSourceText, uri.AbsolutePath, fileKind: fileKind, inGlobalNamespace: inGlobalNamespace);
 
         var filePathService = new FilePathService(TestLanguageServerFeatureOptions.Instance);
         var mappingService = new RazorDocumentMappingService(filePathService, new TestDocumentContextFactory(), LoggerFactory);
diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs
index a9e5754d120..96fdd8f9145 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/RazorFormattingTest.cs
@@ -49,8 +49,8 @@ @section Scripts {
             fileKind: FileKinds.Legacy);
     }
 
-    [Fact]
-    public async Task CodeBlock_SpansMultipleLines()
+    [Theory, CombinatorialData]
+    public async Task CodeBlock_SpansMultipleLines(bool inGlobalNamespace)
     {
         await RunFormattingTestAsync(
             input: """
@@ -74,7 +74,8 @@ private void IncrementCount()
                             currentCount++;
                         }
                     }
-                    """);
+                    """,
+            inGlobalNamespace: inGlobalNamespace);
     }
 
     [Theory, CombinatorialData]

From cfb9176c70b3a35ea6178dc1dad5116caf88f48e Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 20 Mar 2024 16:27:41 +0100
Subject: [PATCH 09/11] Fix global namespace testing

---
 .../Formatting_NetFx/FormattingTestBase.cs             | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
index 05651a80c7a..a3a96042c3c 100644
--- a/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
+++ b/src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Formatting_NetFx/FormattingTestBase.cs
@@ -275,12 +275,12 @@ @using Microsoft.AspNetCore.Components.Web
 
         var imports = ImmutableArray.Create(importsSnapshot.Object);
         var importsDocuments = ImmutableArray.Create(importsDocument);
-        var documentSnapshot = CreateDocumentSnapshot(path, tagHelpers, fileKind, importsDocuments, imports, projectEngine, codeDocument);
+        var documentSnapshot = CreateDocumentSnapshot(path, tagHelpers, fileKind, importsDocuments, imports, projectEngine, codeDocument, inGlobalNamespace: inGlobalNamespace);
 
         return (codeDocument, documentSnapshot);
     }
 
-    internal static IDocumentSnapshot CreateDocumentSnapshot(string path, ImmutableArray<TagHelperDescriptor> tagHelpers, string? fileKind, ImmutableArray<RazorSourceDocument> importsDocuments, ImmutableArray<IDocumentSnapshot> imports, RazorProjectEngine projectEngine, RazorCodeDocument codeDocument)
+    internal static IDocumentSnapshot CreateDocumentSnapshot(string path, ImmutableArray<TagHelperDescriptor> tagHelpers, string? fileKind, ImmutableArray<RazorSourceDocument> importsDocuments, ImmutableArray<IDocumentSnapshot> imports, RazorProjectEngine projectEngine, RazorCodeDocument codeDocument, bool inGlobalNamespace = false)
     {
         var documentSnapshot = new Mock<IDocumentSnapshot>(MockBehavior.Strict);
         documentSnapshot
@@ -305,9 +305,11 @@ internal static IDocumentSnapshot CreateDocumentSnapshot(string path, ImmutableA
             .Setup(d => d.WithText(It.IsAny<SourceText>()))
             .Returns<SourceText>(text =>
             {
-                var sourceDocument = RazorSourceDocument.Create(text, RazorSourceDocumentProperties.Create(path, path));
+                var sourceDocument = RazorSourceDocument.Create(text, RazorSourceDocumentProperties.Create(
+                    filePath: path,
+                    relativePath: inGlobalNamespace ? Path.GetFileName(path) : path));
                 var codeDocument = projectEngine.ProcessDesignTime(sourceDocument, fileKind, importsDocuments, tagHelpers);
-                return CreateDocumentSnapshot(path, tagHelpers, fileKind, importsDocuments, imports, projectEngine, codeDocument);
+                return CreateDocumentSnapshot(path, tagHelpers, fileKind, importsDocuments, imports, projectEngine, codeDocument, inGlobalNamespace: inGlobalNamespace);
             });
         return documentSnapshot.Object;
     }

From ae4fc316660f0991ba06017a86e31853685e3a1a Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Wed, 20 Mar 2024 16:49:17 +0100
Subject: [PATCH 10/11] Fix formatting in global namespace

---
 .../Formatting/FormattingContext.cs              |  9 ++++++---
 .../Formatting/FormattingSpan.cs                 | 16 +++++++++++++++-
 .../Formatting/FormattingVisitor.cs              |  7 +++++--
 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingContext.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingContext.cs
index 14d96eb5b49..de4352ddd17 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingContext.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingContext.cs
@@ -157,6 +157,7 @@ public IReadOnlyDictionary<int, IndentationContext> GetIndentations()
                         FormattingBlockKind.Markup,
                         razorIndentationLevel: 0,
                         htmlIndentationLevel: 0,
+                        isInGlobalNamespace: false,
                         isInClassBody: false,
                         componentLambdaNestingLevel: 0);
 
@@ -187,20 +188,22 @@ private IReadOnlyList<FormattingSpan> GetFormattingSpans()
         if (_formattingSpans is null)
         {
             var syntaxTree = CodeDocument.GetSyntaxTree();
-            _formattingSpans = GetFormattingSpans(syntaxTree);
+            var inGlobalNamespace = CodeDocument.TryComputeNamespace(fallbackToRootNamespace: true, out var @namespace) &&
+                string.IsNullOrEmpty(@namespace);
+            _formattingSpans = GetFormattingSpans(syntaxTree, inGlobalNamespace: inGlobalNamespace);
         }
 
         return _formattingSpans;
     }
 
-    private static IReadOnlyList<FormattingSpan> GetFormattingSpans(RazorSyntaxTree syntaxTree)
+    private static IReadOnlyList<FormattingSpan> GetFormattingSpans(RazorSyntaxTree syntaxTree, bool inGlobalNamespace)
     {
         if (syntaxTree is null)
         {
             throw new ArgumentNullException(nameof(syntaxTree));
         }
 
-        var visitor = new FormattingVisitor();
+        var visitor = new FormattingVisitor(inGlobalNamespace: inGlobalNamespace);
         visitor.Visit(syntaxTree.Root);
 
         return visitor.FormattingSpans;
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingSpan.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingSpan.cs
index 830901c8393..0afa79033e6 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingSpan.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingSpan.cs
@@ -14,6 +14,7 @@ public FormattingSpan(
         FormattingBlockKind blockKind,
         int razorIndentationLevel,
         int htmlIndentationLevel,
+        bool isInGlobalNamespace,
         bool isInClassBody = false,
         int componentLambdaNestingLevel = 0)
     {
@@ -23,6 +24,7 @@ public FormattingSpan(
         BlockKind = blockKind;
         RazorIndentationLevel = razorIndentationLevel;
         HtmlIndentationLevel = htmlIndentationLevel;
+        IsInGlobalNamespace = isInGlobalNamespace;
         IsInClassBody = isInClassBody;
         ComponentLambdaNestingLevel = componentLambdaNestingLevel;
     }
@@ -41,6 +43,8 @@ public FormattingSpan(
 
     public int IndentationLevel => RazorIndentationLevel + HtmlIndentationLevel;
 
+    public bool IsInGlobalNamespace { get; }
+
     public bool IsInClassBody { get; }
 
     public int ComponentLambdaNestingLevel { get; }
@@ -49,7 +53,17 @@ public int MinCSharpIndentLevel
     {
         get
         {
-            var baseIndent = IsInClassBody ? 2 : 3;
+            var baseIndent = 1;
+
+            if (!IsInGlobalNamespace)
+            {
+                baseIndent++;
+            }
+
+            if (!IsInClassBody)
+            {
+                baseIndent++;
+            }
 
             return baseIndent + ComponentLambdaNestingLevel;
         }
diff --git a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingVisitor.cs b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingVisitor.cs
index fbe95eecd30..f670882725b 100644
--- a/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingVisitor.cs
+++ b/src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Formatting/FormattingVisitor.cs
@@ -18,6 +18,7 @@ internal class FormattingVisitor : SyntaxWalker
 {
     private const string HtmlTag = "html";
 
+    private readonly bool _inGlobalNamespace;
     private readonly List<FormattingSpan> _spans;
     private FormattingBlockKind _currentBlockKind;
     private SyntaxNode? _currentBlock;
@@ -26,8 +27,9 @@ internal class FormattingVisitor : SyntaxWalker
     private int _currentComponentIndentationLevel = 0;
     private bool _isInClassBody = false;
 
-    public FormattingVisitor()
+    public FormattingVisitor(bool inGlobalNamespace)
     {
+        _inGlobalNamespace = inGlobalNamespace;
         _spans = new List<FormattingSpan>();
         _currentBlockKind = FormattingBlockKind.Markup;
     }
@@ -481,7 +483,8 @@ private void WriteSpan(SyntaxNode node, FormattingSpanKind kind)
             _currentBlockKind,
             _currentRazorIndentationLevel,
             _currentHtmlIndentationLevel,
-            _isInClassBody,
+            isInGlobalNamespace: _inGlobalNamespace,
+            isInClassBody: _isInClassBody,
             _currentComponentIndentationLevel);
 
         _spans.Add(span);

From 85862509f5e24b2748ea05e14a354a97eb587b0d Mon Sep 17 00:00:00 2001
From: Jan Jones <janjones@microsoft.com>
Date: Thu, 11 Apr 2024 11:15:21 +0200
Subject: [PATCH 11/11] Check global namespace flag instead of empty string

---
 .../src/CSharp/ComponentTagHelperDescriptorProvider.cs       | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs
index 0f53faceb9f..265aef0c788 100644
--- a/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs
+++ b/src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/CSharp/ComponentTagHelperDescriptorProvider.cs
@@ -115,10 +115,9 @@ private static TagHelperDescriptor CreateNameMatchingDescriptor(
 
             if (fullyQualified)
             {
-                var containingNamespace = type.ContainingNamespace.ToDisplayString(SymbolExtensions.FullNameTypeDisplayFormat);
-                var fullName = string.IsNullOrEmpty(containingNamespace)
+                var fullName = type.ContainingNamespace.IsGlobalNamespace
                     ? type.Name
-                    : $"{containingNamespace}.{type.Name}";
+                    : $"{type.ContainingNamespace.ToDisplayString(SymbolExtensions.FullNameTypeDisplayFormat)}.{type.Name}";
 
                 builder.TagMatchingRule(r =>
                 {