core-js changelog and release notes, page 3 | npm

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3.3.013 Oct 2019withdrawn: core-js@<3.23.3 is no longer maintained and not recommended for usage due to the number of issues. Because of the V8 engine whims, feature detection in old core-js versions could cause a slowdown up to 100x even if nothing is polyfilled. Some versions have web compatibility issues. Please, upgrade your dependencies to the actual version of core-js.Breaking2 sources agree

…It's a breaking change, but since it's a breaking change in the ES spec, it's added at the minor release

String#{ matchAll, replaceAll } throws an error on non-global regex argument per the decision from TC39 meetings (+ this PR). It's a breaking change, but since it's a breaking change in the ES spec, it's added at the minor release
globalThis moved to stable ES, per October TC39 meeting
Promise.any moved to stage 3, some minor internal changes, per October TC39 meeting
String#replaceAll moved to stage 3, per October TC39 meeting
Added iterator helpers stage 2 proposal:
- Iterator
  - Iterator.from
  - Iterator#asIndexedPairs
  - Iterator#drop
  - Iterator#every
  - Iterator#filter
  - Iterator#find
  - Iterator#flatMap
  - Iterator#forEach
  - Iterator#map
  - Iterator#reduce
  - Iterator#some
  - Iterator#take
  - Iterator#toArray
  - Iterator#@@toStringTag
- AsyncIterator
  - AsyncIterator.from
  - AsyncIterator#asIndexedPairs
  - AsyncIterator#drop
  - AsyncIterator#every
  - AsyncIterator#filter
  - AsyncIterator#find
  - AsyncIterator#flatMap
  - AsyncIterator#forEach
  - AsyncIterator#map
  - AsyncIterator#reduce
  - AsyncIterator#some
  - AsyncIterator#take
  - AsyncIterator#toArray
  - AsyncIterator#@@toStringTag
Updated Map#upsert (Map#updateOrInsert before) proposal
- Moved to stage 2, per October TC39 meeting
- Map#updateOrInsert renamed to Map#upsert
- Added WeakMap#upsert
- You can don't pass one of the callbacks
Added a workaround for iOS Safari MessageChannel + bfcache bug, #624
Added a workaround for Chrome 33 / Android 4.4.4 Promise bug, #640
Replaced broken URL constructor in Safari and URLSearchParams in Chrome 66-, #656
Added compat data for Node up to 12.11, FF 69, Samsung up to 10.2 and Phantom 1.9
Math.hypot marked as not supported in Chrome 77 since a bug in this method was not fixed before the stable Chrome 77 release
Fixed unnecessary exposing on Symbol.matchAll in esnext.string.match-all, #626
Fixed missed cases access the .next method once, at the beginning, of the iteration protocol
Show similar postinstall messages only once per npm i, #597, thanks @remy

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3.0.019 Mar 2019withdrawn: core-js@<3.23.3 is no longer maintained and not recommended for usage due to the number of issues. Because of the V8 engine whims, feature detection in old core-js versions could cause a slowdown up to 100x even if nothing is polyfilled. Some versions have web compatibility issues. Please, upgrade your dependencies to the actual version of core-js.

See more info in this article and the changelog.

See more info in this article and the changelog.

Open source →

Additional notes

Features
- Add new features:
  - Object.fromEntries (ECMAScript 2019)
  - Symbol#description (ECMAScript 2019)
  - New Set methods (stage 2 proposal)
    - Set#difference
    - Set#intersection
    - Set#isDisjointFrom
    - Set#isSubsetOf
    - Set#isSupersetOf
    - Set#symmetricDifference
    - Set#union
  - Promise.allSettled (stage 2 proposal)
  - Getting last item from Array (stage 1 proposal)
    - Array#lastItem
    - Array#lastIndex
  - String#replaceAll (stage 1 proposal)
  - String#codePoints (stage 1 proposal)
  - New collections methods (stage 1 proposal)
    - Map.groupBy
    - Map.keyBy
    - Map#deleteAll
    - Map#every
    - Map#filter
    - Map#find
    - Map#findKey
    - Map#includes
    - Map#keyOf
    - Map#mapKeys
    - Map#mapValues
    - Map#merge
    - Map#reduce
    - Map#some
    - Map#update
    - Set#addAll
    - Set#deleteAll
    - Set#every
    - Set#filter
    - Set#find
    - Set#join
    - Set#map
    - Set#reduce
    - Set#some
    - WeakMap#deleteAll
    - WeakSet#addAll
    - WeakSet#deleteAll
  - compositeKey and compositeSymbol methods (stage 1 proposal)
  - Number.fromString (stage 1 proposal)
  - Math.seededPRNG (stage 1 proposal)
  - Symbol.patternMatch (for stage 1 pattern matching proposal)
  - Symbol.dispose (for stage 1 using statement proposal)
  - Promise.any (with AggregateError) (stage 0 proposal)
  - URL and URLSearchParam from URL standard, also stage 0 proposal to ECMAScript
    - URL
      - URL#href
      - URL#origin
      - URL#protocol
      - URL#username
      - URL#password
      - URL#host
      - URL#hostname
      - URL#port
      - URL#pathname
      - URL#search
      - URL#searchParams
      - URL#hash
      - URL#toString
      - URL#toJSON
    - URLSearchParams
      - URLSearchParams#append
      - URLSearchParams#delete
      - URLSearchParams#get
      - URLSearchParams#getAll
      - URLSearchParams#has
      - URLSearchParams#set
      - URLSearchParams#sort
      - URLSearchParams#toString
      - URLSearchParams#keys
      - URLSearchParams#values
      - URLSearchParams#entries
      - URLSearchParams#@@iterator
  - .forEach method on iterable DOM collections (#329)
- Improve existing features:
  - Add triggering unhandled Promise rejection events (instead of only global handlers), #205.
  - Wrap fetch for correct with polyfilled Promise and preventing problems like #178, #332, #371.
  - Add support of @@isConcatSpreadable to Array#concat.
  - Add support of @@species to Array#{concat, filter, map, slice, splice}.
  - Add direct .exec calling to RegExp#{@@replace, @@split, @@match, @@search}. Also, added fixes for RegExp#exec method. #411, #434, #453, thanks @nicolo-ribaudo.
  - Correct iterators prototypes chain, related #261.
  - Correct Typed Arrays prototypes chain, related #378.
  - Make the internal state of polyfilled features completely unobservable, #146.
  - Add validation of receiver's internal class to missed non-generic methods.
  - Fix descriptors of global properties.
  - In the version without global pollution, if Object#toString does not support @@toStringTag, add to wrapped prototypes own toString method with @@toStringTag logic, see #199.
- Update standard features and proposals:
  - asap (old stage 0 proposal) replaced by queueMicrotask (a part of HTML spec)
  - Update Observable (#257, #276, etc.)
  - Update Array#flatten -> Array#flat and Array#flatMap
  - Update global stage 3 proposal - rename global to globalThis
  - Update String#matchAll (proposal-string-matchall#17, proposal-string-matchall#38, proposal-string-matchall#41, etc.) and move to the stage 3
  - Update .name properties of String#{trimStart, trimEnd , trimLeft, trimRight}, move to the stage 3
  - Remove mongolian vowel separator (U+180E) from the list of whitespaces for methods like String#trim (ES6 -> ES7)
- Mark ES2016, ES2017, ES2018, ES2019 features as stable:
  - Array#{ flat, flatMap }
  - { Array, %TypedArray% }#includes
  - Object.{ values, entries}
  - Object.getOwnPropertyDescriptors
  - String#{ padStart, padEnd }
  - String#{ trimStart, trimEnd, trimLeft, trimRight }
  - Promise#finally
  - Symbol.asyncIterator
  - Object#__(define|lookup)[GS]etter__
- Remove obsolete features:
  - Error.isError (withdrawn)
  - System.global and global (replaced by globalThis)
  - Map#toJSON and Set#toJSON (rejected)
  - RegExp.escape (rejected)
  - Reflect.enumerate (removed from the spec)
  - Unnecessary iteration methods from CSSRuleList, MediaList, StyleSheetList
- No more non-standard features, finally removed:
  - Dict
  - Object.{classof, isObject, define, make}
  - Function#part
  - Number#@@iterator
  - String#{escapeHTML, unescapeHTML}
  - delay
- Add .sham flag to features which can't be properly polyfilled and / or not recommended for usage:
  - Symbol constructor - we can't add new primitives. Object.prototype accessors too expensive.
  - Object.{create, defineProperty, defineProperties, getOwnPropertyDescriptor, getOwnPropertyDescriptors}, Reflect.{defineProperty, getOwnPropertyDescriptor} can't be properly polyfilled without descriptors support.
  - Object.{freeze, seal, preventExtensions}, Reflect.preventExtensions can't be properly polyfilled in ES3 environment.
  - Object.getPrototypeOf can be deceived in ES3 environment.
  - Reflect.construct can't be polyfilled for a correct work with newTarget argument on built-ins.
  - Typed Array constructors polyfill is quite correct but too expensive.
  - URL constructor in engines without descriptors support.
Bug and compatibility fixes:
- Fix deoptimisation of iterators in V8, #377.
- Fix import of property before constructor which should contain this property, #262.
- Fix some cases of IE11 WeakMap frozen keys fallback, #384.
- Fix non-enumerable integer keys issue because of Nashorn ~ JDK8 bug, #389.
- Fix Safari 12.0 Array#reverse bug.
- One more fix for microtasks in iOS related #339.
- Added a fallback for Rhino bug, #440.
- Many other internal fixes and improvements.
Repository:
- Change core-js repository structure to monorepo with packages in /packages/ directory.
- Clean-up it, remove all possible duplicates, generated files, etc.
Packages:
- Extract a version without global namespace pollution to a separate core-js-pure package (replacement for core-js/library).
- Leave only one pair of bundles (global, with all polyfills) and move it to core-js-bundle package.
- Remove bundling logic from core-js package, leave it only in core-js-builder package.
- Clean-up packages.
- Because of all approaches, reduce size of packages from ~2mb for core-js@2 to:
  - ~500kb for core-js package
  - ~440kb for core-js-pure package
- Finally remove bower.json
CommonJS API, namespaces:
- Add availability configuration of aggressiveness.
- Move core-js/library to separate core-js-pure package.
- Because of removing all non-standard features, we no longer need core-js/shim entry point, replace it just with core-js.
- Move all features from ES5, ES2015, ES2016, ES2017, ES2018 and ES2019 to one namespace for stable ES - it's available as core-js/es, all those features in modules folder has es. prefix.
- Change prefix for ES proposals from es7. to esnext., they no longer available in core-js/es7, use core-js/stage/* instead of that.
- Rename core-js(/library)/fn to core-js(-pure)/features for improve readability.
- Allow more granular inclusion of features from /es/ path (for example, core-js/es/array/from).
- Add /stable/ entry points as an equal of /features/ for stable features, without proposals.
- Add /proposals/ entry points for allow include all features from one proposal (for example, core-js/proposals/reflect-metadata).
- Add /es|stable|features/instance/ entry points for getting polyfill of the related method for passed instance (could be used in cases like babel-runtime).
- Split typed arrays polyfills. Now you can, for example, load only required method (for example, core-js/es/typed-array/from).
- Extract well-known symbols definition from es.symbol module for loading only required features, for example, in MS Edge.
- Rename web.dom namespace to web.dom-collections.
- Rename es6.regexp.{match, replace, search, split} -> es.string.{match, replace, search, split} - mainly it's fixes / adding support of well-known symbols to string methods, only in second place adding related methods to regexp prototype.
- Relax /modules/ directory by moving internal modules to /internals/ directory.
- Remove deprecated array entry points: core-js(/library)/fn/array/{pop, push, reverse, shift, unshift}.
- core object no longer available in the global version, entry points which previously returned it now returns globalThis object. Also, don't set global core property.
- Add some missing entry points.
Tools, tests, code quality:
- Added core-js-compat package with:
  - Data about the necessity of core-js modules and API for getting a list of required core-js modules by browserslist query, #466.
  - Data which modules load by each entry point (mainly useful for tools like @babel/preset-env).
  - Data which modules added in minor versions (mainly useful for tools like @babel/preset-env).
- core-js-builder package:
  - Added targets option with browserslist query.
  - Removed an option for generation bundle of a version without global namespace pollution - now it's an odd use case.
  - Removed UMD wrapper from a generated code of bundles - we don't need it for a global polyfill.
- Getting rid of LiveScript, usage another language in JS standard library looks strange and impedes usage of tools like ESLint:
  - Tests are rewritten to JS.
  - Scripts are rewritten to JS.
- Babel with minimalistic config (which should work anywhere) used on tests.
- ESLint used on tests and tools.
- Source code refactored for improving readability.

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