Comparison of generator vs. promise + callback

recursive-readdir.ts

import * as rx from "rxjs";
import * as fs from "fs-promise";
import * as path from "path";


function readdir(dir) {
    return rx.Observable.create((observer: rx.Observer<string>) => {
        fs.readdir(dir).then(async files => {
            for (const file of files) {
                let fullPath = path.join(dir, file);
                let stat = await fs.stat(fullPath);

                if (stat.isDirectory()) {
                    await new Promise(resolve => readdir(fullPath).subscribe(file => observer.next(file), e => observer.error(e), resolve));
                } else {
                    observer.next(fullPath);
                }
            }
            observer.complete();
        });
    });
}

async function readdirPromise(dir: string, fileCallback: (filename: string) => void) {
    return new Promise(resolve => {
        fs.readdir(dir).then(async files => {
            for (const file of files) {
                let fullPath = path.join(dir, file);
                let stat = await fs.stat(fullPath);

                if (stat.isDirectory()) {
                    await readdirPromise(fullPath, fileCallback);
                } else {
                    fileCallback(fullPath);
                }
            }
            resolve();
        });
    });
}

readdir('/tmp/tree').subscribe(
    file => console.log(file),
    err => console.error(err),
    () => console.log('Done')
);

readdirPromise('/tmp/tree', file => console.log(file)).then(
    () => console.log('Done')
);