fileobject-walker

Walk fileobjects recursively and apply a provided payload to them.

Installation

Just install from npm:

npm install @mischback/fileobject-walker

Usage

The fileObjectWalker() accepts two mandatory and unlimited optional parameters.

• startingPoint: A file or directory (provided as string) as starting point of the walker. If specified as a relative path, the function will resolve it (make it absolute) with the current working directory of your Node process as root.
• payload: The function to execute on files. The function must accept a filename, specified as string, as its first parameter. It may accept more parameters for its internal control flow (see below). The function is expected to work Promise-based.
• any parameter provided after payload are considered parameters for the provided payload function and are passed on when executing the payload.

See the following application in TypeScript. Please note, that the parameters passed to payload are of type unknown and must be cast to their original type inside of the payload function.

import { fileObjectWalker } from "../walker";
import { basename } from "path";

function examplePayload(
  filename: string,
  payloadArg1: unknown,
  payloadArg2: unknown
): Promise<{ [key: string]: string }> {
  const arg1 = payloadArg1 as string;
  const arg2 = payloadArg2 as number;

  return new Promise((resolve, reject) => {
    if (basename(filename) !== arg1) return resolve({ [filename]: "skipped" });

    return reject(arg2);
  });
}

fileObjectWalker("./", examplePayload, "foo.txt", 1337)
  .then((retVal) => {
    // produces a long list of files if there is no "foo.txt" in your current
    // working directory or any of its subfolders
    console.log(retVal);
  })
  .catch((err) => {
    // 1337 if there is a "foo.txt" in your current working directory or any of
    //  its subfolders
    console.log(err);
  });

Contributing

Issues, pull requests and feature requests are welcome. Just use the project's issue tracker.

fileobject-walker is implemented in TypeScript and compiled/transpiled to actual JavaScript on release.

License

MIT