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

3.21.1 - 2022.02.17

• Added a bugfix for the WebKit Array.prototype.{ groupBy, groupByToMap } implementation
• core-js-compat targets parser transforms engine names to lower case
• atob / btoa marked as fixed in NodeJS 17.5
• Added Electron 18.0 compat data mapping
• Added Deno 1.20 compat data mapping

3.21.0 - 2022.02.02

• Added Base64 utility methods:
  • atob
  • btoa
• Added the proper validation of arguments to some methods from web standards
• Forced replacement of all features from early-stage proposals for avoiding possible web compatibility issues in the future
• Added Rhino 1.7.14 compat data
• Added Deno 1.19 compat data mapping
• Added Opera Android 66 and 67 compat data mapping
• Added iOS Safari 15.3 and 15.4 compat data mapping

3.20.3 - 2022.01.15

• Detects and replaces broken third-party Function#bind polyfills, uses only native Function#bind in the internals
• structuredClone should throw an error if no arguments passed
• Changed the structure of notes in __core-js_shared__

3.20.2 - 2022.01.02

• Added a fix of a V8 ~ Chrome 36- Object.{ defineProperty, defineProperties } bug, Babel issue
• Added fixes of some different %TypedArray%.prototype.set bugs, affects modern engines (like Chrome < 95 or Safari < 14.1)

3.20.1 - 2021.12.23

• Fixed the order of calling reactions of already fulfilled / rejected promises in Promise.prototype.then, #1026
• Fixed possible memory leak in specific promise chains
• Fixed some missed dependencies of entries
• Added Deno 1.18 compat data mapping

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

3.19.3 - 2021.12.06

• Fixed internal slots check in methods of some built-in types, #1017
• Fixed URLSearchParams iterator .next that should be enumerable by the spec
• Refactored Subscription
• Added NodeJS 17.2 compat data mapping

3.19.2 - 2021.11.29

• Added a workaround for a UC Browser specific version bug with unobservable RegExp#sticky flag, #1008, #1015
• Added handling of comments and specific spaces to Function#name polyfill, #1010, thanks @ildar-shaimordanov
• Prevented some theoretical cases of breaking / observing the internal state by patching Array.prototype[@@species]
• Refactored URL and URLSearchParams
• Added iOS Safari 15.2 compat data mapping
• Added Electron 17.0 compat data mapping
• Updated Deno compat data mapping

3.19.1 - 2021.11.03

• Added a workaround for FF26- bug where ArrayBuffers are non-extensible, but Object.isExtensible does not report it:
  • Fixed in Object.{ isExtensible, isSealed, isFrozen } and Reflect.isExtensible
  • Fixed handling of ArrayBuffers as collections keys
• Fixed Object#toString on AggregateError in IE10-
• Fixed possible lack of dependencies of WeakMap in IE8-
• .findLast methods family marked as supported from Chrome 97
• Fixed inheritance of Electron compat data web. modules
• Fixed Safari 15.1 compat data (some features were not added)
• Added iOS Safari 15.1 compat data mapping