medium-rxjs-collection-ajax.ts

import { pipe } from "rxjs";
import { ajax } from "rxjs/ajax"
import { concatMap, filter, ignoreElements } from "rxjs/operators";

/* ... */

collection.traverse(pipe(
  filter(shouldPut),
  concatMap(doc => ajax.put(
    `${uri}/docs/${doc.id}`,
    doc.toJSON(),
    { "Content-Type": "application/json" }
  )),
  ignoreElements()
)).subscribe({
  complete: () => console.log("Finished.")
});