### `@babel/runtime`
- Added `@babel/runtime-corejs3` package and `corejs: 3` options to `@babel/plugin-transform-runtime`.
- Added support of instance methods, fixes#8928.
- Added flag `proposals` (in `corejs: { version: 3, proposals: true }` format) for support all proposals polyfills from `core-js`.
- Used separate directories in runtime for `core-js` entry points with proposals and without.
- Used `get-iterator-method` helper for getting iterators, fixes#2500.
- As a cheap bonus, added support of IE8- (except some cases of `regenerator`).
### `@babel/polyfill`
- Should be deprecated in favor of separate usage required features from `core-js` and `regenerator-runtime` with an informative message.
### `@babel/preset-env`
- Uses for built-ins data from [`core-js-compat`](https://github.com/zloirock/core-js/tree/master/packages/core-js-compat) instead of `compat-table` since information from `compat-table` [is not enough](https://github.com/zloirock/core-js/tree/master/packages/core-js-compat).
- `useBuilIns` now requires direct setting of `corejs` version option, without it will be used `2` by default and shown deprecation warning.
- Added support of minor `core-js` versions for simplify updating in the future.
- For preventing some order-related problems, polyfills in the both `core-js@3` plugins added on `post` stage in the order of `core-js-compat` data.
- Divided plugins and polyfills parts of `preset-env`, instead of 2 internal plugins for adding polyfills, we have 6: usage and entry versions of plugins for `core-js@2`, ### Current state:
`core-js@3`, `regenerator-runtime`.
- Added support `samsung` target (for Samsung Internet) since `core-js-compat` and `compat-table` now contains mapping for this, fixes#6602.
#### `useBuilIns: entry` with `corejs: 3`
- No longer transforms `@babel/polyfill`.
- Transforms **all possible** `core-js` entry points to import of related modules (based on data from [`core-js-compat`](https://unpkg.com/core-js-compat@3.0.0-beta.15/entries.json)).
- Since of this, we no longer need `shippedProposals` / `proposals` flags with `useBuilIns: entry`.
- Removes `regenerator-runtime/runtime` import where it's not required.
#### `useBuilIns: usage` with `corejs: 3`
- In addition to `shippedProposals`, added flag `proposals` (in `corejs: { version: 3, proposals: true }` format) for polyfill all proposals from `core-js`.
- Fixed list of dependencies in built-in definitions.
- Improved the way of determination method / built-in name and source of this method.
- Adds import of required polyfills on `MemberExpression`, `ObjectPattern`, `in` operator.
- Adds import of required polyfills on access to global object properties.
- Adds import of all required common iterators on all syntax features which use iterators protocol (`for-of`, destructuring, spread, `yield` delegation, etc.).
- Adds import of promises on syntax features which use promises (async functions/generators, dynamic import, etc.), fixes#9250, #7402, etc.
### `core-js@2` stuff
I didn't want to tough `core-js@2`-related stuff, however
- Fixed some serious errors in definitions which breaks `Object.getOwnPropertySymbols`, `Symbol.toStringTag` logic, `Promise#finally`, `Array#forEach`, etc.
- `Array#flatMap` and trim methods moved to stable features as a part of ES2019 and loaded by deprecated `@babel/polyfill` and `@babel/preset-env` with `corejs: 2` option.
* add isSpread field
* use argument
* t.booleanLiteral
* fix typo
* push empty-argument object
* .object
* .value
* object field should be an expression
* lint
* update outputs
* isSpread for the second argument is redundant
* add test
* alternating spread
When the `runtime` flag is on (by default), this plugin adds a new helper which wraps the native `RegExp` class to provide groups support. People nees to use a polyfill (I implemented it in core-js) for browsers that don't support ES6 regexps.
This is similar to ec69b4bb1256c061ac76f53dfed09c4283ec6a31, which
was about private instance fields.
Private properties can be non-writable (thanks to decorators), or have
get/set accessors. If we stored this information on the `privateClass`
object, we would need to always use `Object.getOwnPropertyDescriptor`
before reading or writing a property because accessors need to be called
with the correct `this` context (it should be the actual class, not the
object hat stores the private properties). This commit simplifies that
operation a bit by removing the container object.
It also have another advantage, which instance fields already have
thanks to the use of separate weakmaps: unused private static fields
can be tree-shaken away or garbage-collected, while properties of an
object can't. Also, they can be easilier minified.
* Private Static Class Fields Implementation
* Redo testing without class transform for static private
* Add a call() test for private static
* Use Object.defineProperty in loose mode
* Save full descriptor instead of only value for private fields.
Decorators can make private fields non-writable, so we need to store this
information somewhere.
The descriptor can also be used to implement private accessors.
Fix a ReferenceError caused by a typo (`_construct` instead of
`construct`) in the external `wrapNativeSuper` helper. (The typo
doesn't usually cause an error in inline helpers because `_construct`
happens to be the default name given to the `construct` helper
function.)
* Revert "Move subclass inheritance to end (#7772)"
This reverts commit f8ab9466d331871a90f458af40b14e8d831e0c29.
* Only use getPrototypeOf if setPrototypeOf is implemented
* Update fixtures
* Helpers updates
* Update fixtures
* Fall back to getPrototypeOf
* Update fixtures
* Update member-expression-to-functions
1. Babel using British spellings, so `memoise`
2. Provide a helper `AssignmentMemoiser` class, which will assign the memo'd value with the `n`th access.
* Private properties!
* Fixes
* Tests
* Update helper name
* Fix privates that reference other privates
* Don't extend a builtin
* Rebase
* Remove second wrapper from _wrapNativeSuper
* Fix tests on node 4
I DON'T KNOW WHY IT WORKS.
* Update fixtures
* Use Reflect.construct
* Parens
* Fix things
* Fix things
* Undo changes
* Fix with sham
* Typo
We were using `Object.create` to setup the prototype chain at the start of the class definition, which lead to #7771.
I was a bit worried about a speed hit, but it seems everyone optimizes the two patterns the same way.
https://jsbench.github.io/#f9fca52407643d96458a35763b201215Fixes#7771.
* Improve asyncIterator error
When an object is has neither asyncIterator or iterator defined, throw the "not an async iterable" error
* Correct logic
* reduce access
* Update helpers.js
* Improve get/set helper
* fixtures
* Edge cases
* Add loose edge cases
* Spec compliant
* Add issue case
* Even more edge cases!
* Final updates
* Fix name
* Use Reflect.{get, set} when available
* Avoid block scoping in loose
* Remove semicolon
* Do not redefine a non-enumerable
* Get strictness from call site, not helpers
* Add called assertions
* Classes are always strict
* Update test fixture
The boolean expressions returns false in environments where Map is missing.
This change explicitly sets _cache to undefined in such cases, to ensure the cache methods will be ignored.
Keeping the shape of an object constant is a performance improvement for modern javascript engines. At the point of the code change it is certain that the `children` property will be set later, so the property can already be set to `undefined`.
