core-js-builder

I highly recommend reading this: So, what's next?

For some cases could be useful to exclude some core-js features or generate a polyfill for target engines. This API helps conditionally include or exclude certain parts of core-js and build for targets. modules, exclude and targets options are specified in the core-js-compat format.

import builder from 'core-js-builder';

const bundle = await builder({
  // entry / module / namespace / an array of them, by default - all `core-js` modules
  modules: ['core-js/actual', /^esnext\.reflect\./],
  // a blacklist of entries / modules / namespaces, by default - empty list
  exclude: [/^es\.math\./, 'es.number.constructor'],
  // optional browserslist or core-js-compat format query
  targets: '> 0.5%, not dead, ie 9-11',
  // shows summary for the bundle, disabled by default
  summary: {
    // in the console, you could specify required parts or set `true` for enable all of them
    console: { size: true, modules: false },
    // in the comment in the target file, similarly to `summary.console`
    comment: { size: false, modules: true },
  },
  // output format, 'bundle' by default, can be 'cjs' or 'esm', and in this case
  // the result will not be bundled and will contain imports of required modules
  format: 'bundle',
  // optional target filename, if it's missed a file will not be created
  filename: PATH_TO_MY_COREJS_BUNDLE,
});

ℹ️ When using TypeScript, make sure to set esModuleInterop to true.

Changelog

3.39.0 - 2024.10.31

• Changes v3.38.1...v3.39.0
• Iterator helpers proposal:
  • Built-ins:
    • Iterator
      • Iterator.from
      • Iterator.prototype.drop
      • Iterator.prototype.every
      • Iterator.prototype.filter
      • Iterator.prototype.find
      • Iterator.prototype.flatMap
      • Iterator.prototype.forEach
      • Iterator.prototype.map
      • Iterator.prototype.reduce
      • Iterator.prototype.some
      • Iterator.prototype.take
      • Iterator.prototype.toArray
      • Iterator.prototype[@@toStringTag]
  • Moved to stable ES, October 2024 TC39 meeting
  • Added es. namespace modules, /es/ and /stable/ namespaces entries
• Promise.try:
  • Built-ins:
    • Promise.try
  • Moved to stable ES, October 2024 TC39 meeting
  • Added es. namespace module, /es/ and /stable/ namespaces entries
  • Fixed /actual|full/promise/try entries for the callback arguments support
• Math.sumPrecise proposal:
  • Built-ins:
    • Math.sumPrecise
  • Moved to stage 3, October 2024 TC39 meeting
  • Added /actual/ namespace entries, unconditional forced replacement changed to feature detection
• Added Iterator sequencing stage 2.7 proposal:
  • Added built-ins:
    • Iterator.concat
• Map upsert stage 2 proposal:
  • Updated to the new API following the October 2024 TC39 meeting
  • Added built-ins:
    • Map.prototype.getOrInsert
    • Map.prototype.getOrInsertComputed
    • WeakMap.prototype.getOrInsert
    • WeakMap.prototype.getOrInsertComputed
• Extractors proposal moved to stage 2, October 2024 TC39 meeting
• Usage of @@species pattern removed from %TypedArray% and ArrayBuffer methods, tc39/ecma262/3450:
  • Built-ins:
    • %TypedArray%.prototype.filter
    • %TypedArray%.prototype.filterReject
    • %TypedArray%.prototype.map
    • %TypedArray%.prototype.slice
    • %TypedArray%.prototype.subarray
    • ArrayBuffer.prototype.slice
• Some other minor improvements
• Compat data improvements:
  • Uint8Array to / from base64 and hex proposal methods marked as shipped from FF133
  • Added NodeJS 23.0 compat data mapping
  • self descriptor is fixed in Deno 1.46.0
  • Added Deno 1.46 and 2.0 compat data mapping
  • Iterator helpers proposal methods marked as shipped from Bun 1.1.31
  • Added Electron 34 and updated Electron 33 compat data mapping
  • Added Opera Android 85 compat data mapping
  • Added Oculus Quest Browser 35 compat data mapping