This is an implementation of Compound Binary File v.3
Allows reading existing files, creation of the/write operation

Usage

To parse existing Compound Binary File:

const reader = new FileReader(); 
reader.onload = function() { 
    var arrayBuffer = reader.result; 
    var cfb = CompoundFile.fromUint8Array(new Uint8Array(arrayBuffer));
    const rootStorage: RootStorageDirectoryEntry = cfb.getRootStorage();
    const subStorages: StorageDirectoryEntry[] = rootStorage.storages();
    const subStreams: StreamDirectoryEntry[] = rootStorage.streams();
    // etc.
}
reader.readAsArrayBuffer(input.files[0]);

Or alternatively you may use the following syntax if you read file as number[]:

var cfb = CompoundFile.fromUint8Array([...arrayOfBytes]);

To create new Compound File:

const cfb = CompoundFile.empty();
const storage1: StorageDirectoryEntry = cfb.getRootStorage().addStorage('storage1');
const stream1: StreamDirectoryEntry = storage1.addStream('stream1', [1,2,3,4]);
const fileBytes: number[] = cfb.asBytes();