disposable-collections

Objects of disposable things that are disposable themselves.

TypeScript 5.2

Using this correctly with NodeJS requires TypeScript 5.2 as well as a polyfill (see example usage below). I wouldn't recommend it for production code yet, since it's still in beta an a lot of important tooling (prettier, eslint, etc) doesn't support it yet.

Installation

1. Install TypeScript 5.2 (currently yarn add -D typescript@beta or npm i -D typescript@beta).
2. Install this package (yarn add disposable-collections or npm i disposable-collections).

Usage

import { disposableObject } from "disposable-collections";

// assume we have the following disposable file class
class File {
  static open(path): Promise<File>;
  read(): Promise<string>;
  [Symbol.dispose](): void;
}

// now say we want a function to open a bunch of files
// to use elsewhere
function openFiles() {
  return {
    foo: await File('foo').open(),
    bar: await File('bar').open()
  }
}

// this leaks
function doStuff() {
   const files = openFiles();
   // ...
}

// this is annoying and prone to mistakes
function doStuff() {
   const files = openFiles();
   using files.foo;
   using files.bar;
   // ...
}

// this, however, is nice
function doStuff() {
   using files = disposableObject(openFiles());
   // ...
}

TODO

• ESM support
• Fix prettier (TypeScript 5.2 support in progress: https://github.com/prettier/prettier/issues/15004)
• Fix eslint (TypeScript 5.2 support in progress: https://github.com/typescript-eslint/typescript-eslint/issues/7155)