Removing this, since it has been added into another PR

com.unity.shadergraph/Editor/Drawing/MaterialGraphEditWindow.cs

                     return;
 
                 var path = AssetDatabase.GetAssetPath(asset);
-                // Remove the "." in ".extension_name"
-                var extension = Path.GetExtension(path).Substring(1);
+                var extension = Path.GetExtension(path);
-                switch (extension.ToLower())
+                switch (extension)
-                    case ShaderGraphImporter.ShaderGraphExtension:
+                    case ".ShaderGraph":
-                    case ShaderSubGraphImporter.ShaderSubGraphExtension:
+                    case ".ShaderSubGraph":
                         graphType = typeof(SubGraph);
                         break;
                     default:

com.unity.shadergraph/Editor/Importers/ShaderGraphAssetPostProcessor.cs

             RegisterShaders(importedAssets);
 
             bool anyShaders = movedAssets.Any(val => val.EndsWith(ShaderGraphImporter.ShaderGraphExtension, StringComparison.InvariantCultureIgnoreCase));
-            anyShaders |= movedAssets.Any(val => val.EndsWith(ShaderSubGraphImporter.ShaderSubGraphExtension, StringComparison.InvariantCultureIgnoreCase));
+            anyShaders |= movedAssets.Any(val => val.EndsWith("shadersubgraph", StringComparison.InvariantCultureIgnoreCase));
             if (anyShaders)
                 UpdateAfterAssetChange(movedAssets);
         }

com.unity.shadergraph/Editor/Importers/ShaderSubGraphImporter.cs

 [ScriptedImporter(2, "ShaderSubGraph")]
 public class ShaderSubGraphImporter : ScriptedImporter
 {
-    public const string ShaderSubGraphExtension = "shadersubgraph";
     public override void OnImportAsset(AssetImportContext ctx)
     {
         var textGraph = File.ReadAllText(ctx.assetPath, Encoding.UTF8);