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 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({
  modules: ['core-js/actual', 'esnext.reflect'],     // entries / modules / namespaces, by default - all `core-js` modules
  exclude: [/^es\.math\./, 'es.number.constructor'], // a blacklist of entries / 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: PATH_TO_MY_COREJS_BUNDLE,                // optional target filename, if it's missed a file will not be created
});

Changelog

3.22.0 - 2022.04.15

• Change Array by copy proposal:
  • Moved to Stage 3, March TC39 meeting
  • Disabled forced replacement and added /actual/ entry points for methods from this proposal
  • Array.prototype.toSpliced throws a TypeError instead of RangeError if the result length is more than MAX_SAFE_INTEGER, proposal-change-array-by-copy/70
• Added some more atob / btoa fixes:
  • NodeJS <17.9 atob does not ignore spaces, node/42530
  • Actual NodeJS atob does not validate encoding, node/42646
  • FF26- implementation does not properly convert argument to string
  • IE / Edge <16 implementation have wrong arity
• Added /full/ namespace as the replacement for /features/ since it's more descriptive in context of the rest namespaces (/es/ ⊆ /stable/ ⊆ /actual/ ⊆ /full/)
• Avoided propagation of removed parts of proposals to upper stages. For example, %TypedArray%.prototype.groupBy was removed from the Array grouping proposal a long time ago. We can't completely remove this method since it's a breaking change. But this proposal has been promoted to stage 3 - so the proposal should be promoted without this method, this method should not be available in /actual/ entries - but it should be available in early-stage entries to avoid breakage.
• Significant internal refactoring and splitting of modules (but without exposing to public API since it will be a breaking change - it will be exposed in the next major version)
• Bug fixes:
  • Fixed work of non-standard V8 Error features with wrapped Error constructors, #1061
  • null and undefined allowed as the second argument of structuredClone, #1056
• Tooling:
  • Stabilized proposals are filtered out from the core-js-compat -> core-js-builder -> core-js-bundle output. That mean that if the output contains, for example, es.object.has-own, the legacy reference to it, esnext.object.has-own, no longer added.
  • Aligned modules filters of core-js-builder and core-js-compat, now it's modules and exclude options
  • Added support of entry points, modules, regexes, and arrays of them to those filters
  • Missed targets option of core-js-compat means that the targets filter just will not be applied, so the result will contain modules required for all possible engines
• Compat data:
  • .stack property on DOMException marked as supported from Deno 1.15
  • Added Deno 1.21 compat data mapping
  • Added Electron 19.0 and updated 18.0 compat data mapping
  • Added Samsung Internet 17.0 compat data mapping
  • Added Opera Android 68 compat data mapping