Clean up usage of FileKinds

\n\nCommit migrated from b45125a755

src/Razor/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X/src/MvcImportProjectFeature.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version1_X
             }
 
             // Don't add MVC imports for a component - this shouldn't happen for v1, but just in case.
-            if (string.Equals(projectItem.FileKind, FileKinds.Component, StringComparison.OrdinalIgnoreCase))
+            if (FileKinds.IsComponent(projectItem.FileKind))
             {
                 return Array.Empty<RazorProjectItem>();
             }

src/Razor/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version2_X/src/MvcImportProjectFeature.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions.Version2_X
             }
 
             // Don't add MVC imports for a component - this shouldn't happen for v2, but just in case.
-            if (string.Equals(projectItem.FileKind, FileKinds.Component, StringComparison.OrdinalIgnoreCase))
+            if (FileKinds.IsComponent(projectItem.FileKind))
             {
                 return Array.Empty<RazorProjectItem>();
             }

src/Razor/Microsoft.AspNetCore.Mvc.Razor.Extensions/src/MvcImportProjectFeature.cs

@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
             }
 
             // Don't add MVC imports for a component
-            if (string.Equals(projectItem.FileKind, FileKinds.Component, StringComparison.OrdinalIgnoreCase))
+            if (FileKinds.IsComponent(projectItem.FileKind))
             {
                 return Array.Empty<RazorProjectItem>();
             }

src/Razor/Microsoft.AspNetCore.Razor.Language/src/Components/ComponentDocumentClassifierPass.cs

@@ -24,7 +24,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Components
 
         protected override bool IsMatch(RazorCodeDocument codeDocument, DocumentIntermediateNode documentNode)
         {
-            return string.Equals(codeDocument.GetFileKind(), FileKinds.Component);
+            return FileKinds.IsComponent(codeDocument.GetFileKind());
         }
 
         protected override CodeTarget CreateTarget(RazorCodeDocument codeDocument, RazorCodeGenerationOptions options)

src/Razor/Microsoft.AspNetCore.Razor.Language/src/Components/ComponentImportProjectFeature.cs

@@ -34,7 +34,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Components
             }
 
             // Don't add Component imports for a non-component.
-            if (!string.Equals(projectItem.FileKind, FileKinds.Component, StringComparison.OrdinalIgnoreCase))
+            if (!FileKinds.IsComponent(projectItem.FileKind))
             {
                 return Array.Empty<RazorProjectItem>();
             }

src/Razor/Microsoft.AspNetCore.Razor.Language/src/DefaultRazorIntermediateNodeLoweringPhase.cs

@@ -44,7 +44,7 @@ namespace Microsoft.AspNetCore.Razor.Language
             // We need to decide up front if this document is a "component" file. This will affect how
             // lowering behaves.
             LoweringVisitor visitor;
-            if (string.Equals(FileKinds.Component, codeDocument.GetFileKind(), StringComparison.OrdinalIgnoreCase) &&
+            if (FileKinds.IsComponent(codeDocument.GetFileKind()) &&
                 syntaxTree.Options.FeatureFlags.AllowComponentFileKind)
             {
                 visitor = new ComponentFileKindVisitor(document, builder, syntaxTree.Options.FeatureFlags)

src/Razor/Microsoft.AspNetCore.Razor.Language/src/FileKinds.cs

@@ -1,6 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
+using System.IO;
+
 namespace Microsoft.AspNetCore.Razor.Language
 {
     public static class FileKinds
@@ -8,5 +11,28 @@ namespace Microsoft.AspNetCore.Razor.Language
         public static readonly string Component = "component";
 
         public static readonly string Legacy = "mvc";
+
+        public static bool IsComponent(string fileKind)
+        {
+            // fileKind might be null.
+            return string.Equals(fileKind, FileKinds.Component, StringComparison.OrdinalIgnoreCase);
+        }
+
+        public static string GetFileKindFromFilePath(string filePath)
+        {
+            if (filePath == null)
+            {
+                throw new ArgumentNullException(nameof(filePath));
+            }
+
+            if (string.Equals(".razor", Path.GetExtension(filePath), StringComparison.OrdinalIgnoreCase))
+            {
+                return FileKinds.Component;
+            }
+            else
+            {
+                return FileKinds.Legacy;
+            }
+        }
     }
 }

src/Razor/Microsoft.AspNetCore.Razor.Language/src/RazorProjectItem.cs

@@ -1,11 +1,8 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using System;
 using System.Diagnostics;
 using System.IO;
-using Microsoft.AspNetCore.Razor.Language.Components;
-using Microsoft.AspNetCore.Razor.Language.Intermediate;
 
 namespace Microsoft.AspNetCore.Razor.Language
 {
@@ -45,18 +42,7 @@ namespace Microsoft.AspNetCore.Razor.Language
         {
             get
             {
-                if (FilePath == null)
+                return FilePath == null ? null : FileKinds.GetFileKindFromFilePath(FilePath);
-                {
-                    return null;
-                }
-                else if (string.Equals(".razor", Path.GetExtension(FilePath), StringComparison.OrdinalIgnoreCase))
-                {
-                    return FileKinds.Component;
-                }
-                else
-                {
-                    return FileKinds.Legacy;
-                }
             }
         }