Transform Stream<Item> to Stream<List<Item>>

Issue

I try to get all files in folder by Stream.

Directort(path).list() returns Stream<FileSystemEntity>.

I want returns Stream<List<FileSystemEntity>>.

Example:

1 => 1
2 => 1,2
3 => 1,2,3

Solution

scan operator from rxdart is the best answer
https://pub.dev/documentation/rxdart/latest/rx/ScanExtension/scan.html
https://rxjs.dev/api/operators/scan

Stream<FileSystemEntity> source$ = ...;

Stream<List<FileSystemEntity>> result$ = source$.scan(
    (acc, element, _) => [...acc, element],
    [],
);

Answered By – Petrus Nguyễn Thái Học

Answer Checked By – Senaida (FlutterFixes Volunteer)