I am using @azure/storage-blob:^12.8.0, @azure/storage-queue: ^12.7.0 packages to authenticate and connect to Azure blob storage, authentication goes through Managed Identities and the destination granted access with Storage Blob Data Contributor role, below is my code

const credentialOptions = {
    managedIdentityClientId: process.env.MANAGED_IDENTITY_CLIENT_ID
};

const CONTAINER_NAME = 'C1';
const credential = new DefaultAzureCredential(credentialOptions);
const blobSvc = new BlobServiceClient(process.env.STORAGE_HOST, credential);
const containerClient = blobSvc.getContainerClient(CONTAINER_NAME);

export const store = async (file: string, folder: string) => {    
    const fileName = path.basename(file);
    const blob = `${folder}/${fileName}`;
    try {
        console.debug(`starting store ${blob}...`);      
        const blobClient = containerClient.getBlockBlobClient(blob);
        await blobClient.uploadFile(file);
        console.debug('store done.');
        return blob;
    }
    catch (err) {
        console.error(err);       
        throw Error(err);
    }
};


// in other module 
import {store} from 'BlobStorageHelper';

store('folder1/folder2/folder3', '/temporary/path/to/the/file.jpg');

everything works except that the file is stored in the wrong place, for example, by calling store('folder1/folder2/folder3', 'path/file.jpg') I expect the file to be stored at folder1/folder2/folder3/file.jpg but the file gets stored at C1/folder1/folder2/folder3/file.jpg C1 is the name of the container which is wrong and should not happen, the code runs as Azure functions node.

to make it clear, the expectation is

• C1 (the container)
  • folder1
    • folder2
      • folder3
        • file.jpg

but the actual result is

• C1 (the container)
  • C1
    • folder1
      • folder2
        • folder3
          • file.jpg

Any idea ?