* Handling babylon parsing errors in a better way
* Better error messages + Helpful URLs
* Replaced message from babylon completely
* Add importMeta plugin to the map
Currently, Babel is treating JSXIdentifier, JSXMemberExpression, and JSXEmptyExpression as expressions as well, which means Babel will for example incorrectly allow you to place these anywhere an expression is wanted.
Closes#6851.
`this.blockPath.get("body")` constructs an array of paths corresponding to each node in `blocks.body` so takes O(n) time if n is that length. We were re-constructing that array on each iteration, so the entire loop was O(n^2).
On files with many statements in a single block (such as Rollup-generated bundles), this takes a large portion of time. In particular, this makes transforming react-dom.development.js about 40% faster. Not that you should be transforming our bundle with Babel.
Test Plan:
Make an HTML file with these three lines and watch it in the Chrome Performance tab to see timings (on my machine: 2.9s before, 1.6s after):
```
<!DOCTYPE html>
<script src="https://unpkg.com/babel-standalone@7.0.0-beta.3/babel.js"></script>
<script type="text/babel" src="https://unpkg.com/react-dom@16.2.0/umd/react-dom.development.js"></script>
```
This commit introduces 4 changes:
1) Function declarations are wrapped using function declarations.
This has two advantages:
- We can rely on native hoisting, instead of using _blockHoist
- The function isn't wrapped until it is called. This avoids
problems where `regeneratorRuntime.wrap` was called before
that `babel-polyfill` was imported.
Example:
function fn() {}
// becomes
function fn() { return _fn.apply(this, arguments); }
function _fn() {
_fn = _wrapper(/* Original function ... */);
return _fn.apply(this, arguments);
}
2) Use a single template for both named and anonymous function
expressions. They already had the same behavior, but the one
used for named functions was a bit longer.
3) Use normal functions instead of arrow functions to wrap
function expressions.
4) Generate a name based on the original one for wrapped
functions (e.g. `foo` becomes `_foo` instead of `_ref`).
* Split exportExtensions into two plugins in babylon
* rename proposal-export-default to proposal-export-default-from
* rename proposal-export-namespace to proposal-export-namespace-from
* Consider reexports for bindingKindLookup.
* Update test cases according to reexports change
* Fix order for assign reexports.
* void 0 assignation to module keys only for loose mode.
* Create buildReexportsFromMeta helper.
* Update umd/amd fixtures.
* Refactor reexports build.
* Hoist template for reexports.
* Use map as a second argument of Array.from.
* Remove unnecessary export.
