[storage-blob] allow empty blobName to support root directory in datalake (Azure#12890)

* allow empty blobName to support root directory in datalake

* remove .only

* Merge branch 'master' into storage/issues/12813

* changelog

Author: ljian3377

sdk/storage/storage-blob/src/Clients.ts

@@ -2451,9 +2451,7 @@ export class BlobClient extends StorageClient {
       //   doing the same in the SDK side so that the user doesn't have to replace "\" instances in the blobName
       blobName = blobName.replace(/\\/g, "/");
 
-      if (!blobName) {
-        throw new Error("Provided blobName is invalid.");
-      } else if (!containerName) {
+      if (!containerName) {
         throw new Error("Provided containerName is invalid.");
       }
 

sdk/storage/storage-file-datalake/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## 12.3.0-beta.2 (Unreleased)
 
+- Now you can get the functionality of the root directory via the `DataLakeDirectoryClient` created via `FileSystemClient.getDirectoryClient("")`. Fixed bug [12813](https://github.com/Azure/azure-sdk-for-js/issues/12813).
 
 ## 12.3.0-beta.1 (2020-12-09)
 

sdk/storage/storage-file-datalake/recordings/node/sas_generation_nodejs_only_for_directory_sas/recording_generatedatalakesasqueryparameters_for_root_directory_should_work.js

@@ -920,6 +920,28 @@ describe("SAS generation Node.js only for directory SAS", () => {
     await directoryClientwithSAS.setPermissions(permissions);
   });
 
+  it("generateDataLakeSASQueryParameters for root directory should work", async () => {
+    const rootDirName = "";
+    const rootDirectoryClient = fileSystemClient.getDirectoryClient(rootDirName);
+
+    const directorySAS = generateDataLakeSASQueryParameters(
+      {
+        fileSystemName: fileSystemClient.name,
+        pathName: rootDirectoryClient.name,
+        isDirectory: true,
+        directoryDepth: 1,
+        expiresOn: tmr,
+        permissions: DirectorySASPermissions.parse("racwdlmeop"),
+        version: "2020-02-10"
+      },
+      sharedKeyCredential as StorageSharedKeyCredential
+    );
+    const sasURL = `${rootDirectoryClient.url}?${directorySAS}`;
+    const directoryClientwithSAS = new DataLakeDirectoryClient(sasURL);
+
+    await directoryClientwithSAS.getAccessControl();
+  });
+
   function getDefualtDirctorySAS(directoryName: string): SASQueryParameters {
     return generateDataLakeSASQueryParameters(
       {