@babel/plugin-transform-async-to-generator

What is @babel/plugin-transform-async-to-generator?

The @babel/plugin-transform-async-to-generator package is a Babel plugin that transforms async functions into generator functions using the regenerator runtime, which is a part of the Facebook Regenerator project. This transformation allows async functions to be used in environments that do not natively support async/await syntax by converting them into ES2015/ES6 compatible code.

What are @babel/plugin-transform-async-to-generator's main functionalities?

Transform async functions to generators

This feature allows developers to write asynchronous code using the modern async/await syntax and have it transformed into generator functions that are compatible with older JavaScript engines.

async function foo() {
  await bar();
}
// Transforms to:
function foo() {
  return regeneratorRuntime.async(function foo$(_context) {
    while (1) {
      switch (_context.prev = _context.next) {
        case 0:
          _context.next = 2;
          return regeneratorRuntime.awrap(bar());
        case 2:
        case "end":
          return _context.stop();
      }
    }
  }, null, this);
}

Other packages similar to @babel/plugin-transform-async-to-generator

babel-plugin-transform-async-to-module-method

This package is similar to @babel/plugin-transform-async-to-generator in that it transforms async functions, but it does so by delegating to a specified module method, allowing for custom handling of async functions.

fast-async

Fast-async is a Babel plugin that uses nodent to transform async/await functions. It is designed to be faster than the regenerator-based approach used by @babel/plugin-transform-async-to-generator and does not require a runtime.

babel-preset-env

While not a direct alternative, babel-preset-env includes the capability to transform async functions when the target environments specified do not support them natively. It uses @babel/plugin-transform-async-to-generator as part of its transformation suite when necessary.

README

@babel/plugin-transform-async-to-generator

Turn async functions into ES2015 generators

See our website @babel/plugin-transform-async-to-generator for more information.

Install

Using npm:

npm install --save-dev @babel/plugin-transform-async-to-generator

or using yarn:

yarn add @babel/plugin-transform-async-to-generator --dev

Changelog

v7.25.9 (2024-10-22)

:bug: Bug Fix

• babel-parser, babel-template, babel-types
  • #16905 fix: Keep type annotations in syntacticPlaceholders mode (@liuxingbaoyu)
• babel-helper-compilation-targets, babel-preset-env
  • #16907 fix: support BROWSERSLIST{,_CONFIG} env (@JLHwung)
• Other
  • #16884 Analyze ClassAccessorProperty to prevent the no-undef rule (@victorenator)

:house: Internal

• babel-helper-transform-fixture-test-runner
  • #16914 remove test options flaky (@JLHwung)

:running_woman: Performance

• babel-parser, babel-types
  • #16918 perf: Make VISITOR_KEYS etc. faster to access (@liuxingbaoyu)