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

3.28.0 - 2023.02.14

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

• Change Array by copy proposal:
  • Methods:
    • Array.prototype.toReversed
    • Array.prototype.toSorted
    • Array.prototype.toSpliced
    • Array.prototype.with
    • %TypedArray%.prototype.toReversed
    • %TypedArray%.prototype.toSorted
    • %TypedArray%.prototype.with
  • Moved to stable ES, January 2023 TC39 meeting
  • Added es. namespace modules, /es/ and /stable/ namespaces entries
• Added JSON.parse source text access Stage 3 proposal
  • Methods:
    • JSON.parse patched for support source in reviver function arguments
    • JSON.rawJSON
    • JSON.isRawJSON
    • JSON.stringify patched for support JSON.rawJSON
• Added ArrayBuffer.prototype.transfer and friends Stage 3 proposal:
  • Built-ins:
    • ArrayBuffer.prototype.detached
    • ArrayBuffer.prototype.transfer (only in runtimes with native structuredClone with ArrayBuffer transfer support)
    • ArrayBuffer.prototype.transferToFixedLength (only in runtimes with native structuredClone with ArrayBuffer transfer support)
  • In backwards, in runtimes with native ArrayBuffer.prototype.transfer, but without proper structuredClone, added ArrayBuffer transfer support to structuredClone polyfill
• Iterator Helpers proposal:
  • Split into 2 (sync and async) proposals, async version moved back to Stage 2, January 2023 TC39 meeting
  • Allowed interleaved mapping in AsyncIterator helpers, proposal-iterator-helpers/262
• Explicit Resource Management Stage 3 and Async Explicit Resource Management Stage 2 proposals:
  • InstallErrorCause removed from SuppressedError, January 2023 TC39 meeting, proposal-explicit-resource-management/145
  • Simplified internal behaviour of { AsyncDisposableStack, DisposableStack }.prototype.use, proposal-explicit-resource-management/143
• Added Symbol predicates Stage 2 proposal
  • Methods:
    • Symbol.isRegistered
    • Symbol.isWellKnown
• Number.range Stage 1 proposal and method renamed to Iterator.range
• Function.prototype.unThis Stage 0 proposal and method renamed to Function.prototype.demethodize
• Fixed Safari String.prototype.toWellFormed ToString conversion bug
• Improved some cases handling of array-replacer in JSON.stringify symbols handling fix
• Fixed many other old JSON.{ parse, stringify } bugs (numbers instead of strings as keys in replacer, handling negative zeroes, spaces, some more handling symbols cases, etc.)
• Fixed configurability and ToString conversion of some accessors
• Added throwing proper errors on an incorrect context in some ArrayBuffer and DataView methods
• Some minor DataView and %TypedArray% polyfills optimizations
• Added proper error on the excess number of trailing = in the atob polyfill
• Fixed theoretically possible ReDoS vulnerabilities in String.prototype.{ trim, trimEnd, trimRight }, parse(Int|Float), Number, atob, and URL polyfills in some ancient engines
• Compat data improvements:
  • RegExp.prototype.flags marked as fixed from V8 ~ Chrome 111
  • Added Opera Android 73 compat data mapping
• Added TypeScript definitions to core-js-builder