core-js-builder

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, build for targets specified in core-js-compat format.

const builder = require('core-js-builder');

const bundle = await builder({
  modules: ['es', 'esnext.reflect', 'web'],      // modules / namespaces, by default - all `core-js` modules
  exclude: ['es.math', 'es.number.constructor'], // a blacklist of modules / namespaces, by default - empty list
  targets: '> 0.5%, not dead, ie 9-11',          // optional browserslist or core-js-compat format query
  summary: {                                     // shows summary for the bundle, disabled by default:
    console: { size: true, modules: false },     // in the console, you could specify required parts or set `true` for enable all of them
    comment: { size: false, modules: true },     // in the comment in the target file, similarly to `summary.console`
  },
  filename: './my-core-js-bundle.js',            // optional target filename, if it's missed a file will not be created
});

Changelog

3.20.0 - 2021.12.16

• Added structuredClone method from the HTML spec, see MDN
  • Includes all cases of cloning and transferring of required ECMAScript and platform types that can be polyfilled, for the details see the caveats
  • Uses native structured cloning algorithm implementations where it's possible
  • Includes the new semantic of errors cloning from html/5749
• Added DOMException polyfill, the Web IDL spec, see MDN
  • Includes DOMException and its attributes polyfills with fixes of many different engines bugs
  • Includes DOMException#stack property polyfill in engines that should have it
  • Reuses native DOMException implementations where it's possible (for example, in old NodeJS where it's not exposed as global)
• Added support of cause on all Error types
• Added Error.prototype.toString method polyfill with fixes of many different bugs of JS engines
• Added Number.prototype.toExponential method polyfill with fixes of many different bugs of JS engines
• Array grouping proposal:
  • Moved to stage 3
  • Added Array.prototype.groupByToMap method
  • Removed @@species support
• Added change Array by copy stage 2 proposal:
  • Array.prototype.toReversed
  • Array.prototype.toSorted
  • Array.prototype.toSpliced
  • Array.prototype.with
  • %TypedArray%.prototype.toReversed
  • %TypedArray%.prototype.toSorted
  • %TypedArray%.prototype.toSpliced
  • %TypedArray%.prototype.with
• Added Iterator.prototype.toAsync method from the iterator helpers stage 2 proposal
• Array.fromAsync proposal moved to stage 2
• Added String.cooked stage 1 proposal
• Added Function.prototype.unThis stage 0 proposal
• Added Function.{ isCallable, isConstructor } stage 0 proposal:
  • Function.isCallable
  • Function.isConstructor
• Added a workaround of most cases breakage modern String#at after loading obsolete String#at proposal module, #1019
• Fixed Array.prototype.{ values, @@iterator }.name in V8 ~ Chrome 45-
• Fixed validation of typed arrays in typed arrays iteration methods in V8 ~ Chrome 50-
• Extension of the API, #1012
  • Added a new core-js/actual/** namespace
  • Added entry points for each finished post-ES6 proposal