Syntax name

Explicit Resource Management

Syntax proposal URL

https://github.com/tc39/proposal-explicit-resource-management

Example code

// sync disposal
function * g() {
  using handle = acquireFileHandle(); // block-scoped critical resource
} // cleanup

{
  using obj = g(); // block-scoped declaration
  const r = obj.next();
} // calls finally blocks in `g`

// async disposal
async function * g() {
  using stream = acquireStream(); // block-scoped critical resource
  ...
} // cleanup

{
  await using obj = g(); // block-scoped declaration
  const r = await obj.next();
} // calls finally blocks in `g`

Implementation Checklist

• Ecma262 update: Add using and await using Declarations, SuppressedError, DisposableStack, and AsyncDisposableStack tc39/ecma262#3000
• ESTree update: Add ES2026 estree/estree#324
• Acorn update: using and await using declarations (ES2026) acornjs/acorn#1366 / feat: support using and await using acornjs/acorn#1369
• eslint-visitor-keys update: Not necessary.
• espree update: feat: Add support for ES2026 using and await using declarations js#658
• eslint-scope update: Probably not necessary, but we might want to add a test for it.
• eslint update:
  • feat: add ecmaVersion: 2026, parsing using and await using #19832
  • rules:
    • astUtils.areBracesNecessary() feat: support explicit resource management in core rules #19828
    • init-declarations feat: support explicit resource management in init-declarations #19893
    • no-await-in-loop feat: support explicit resource management in core rules #19828
    • no-const-assign feat: support explicit resource management in no-const-assign #19892
    • no-loop-func feat: support explicit resource management in no-loop-func #19895
    • no-undef-init feat: support explicit resource management in no-undef-init #19894
    • no-unused-vars feat: support explicit resource management in core rules #19828
    • one-var feat: support explicit resource management in one-var #19941
    • prefer-destructuring feat: support explicit resource management in core rules #19828
    • require-await feat: support explicit resource management in core rules #19828

Participation

• I am willing to submit a pull request for this change.

Additional comments

The specifications can be found at the following link:

tc39/ecma262#3000
https://arai-a.github.io/ecma262-compare/?pr=3000