* Removed unnecessary 'return' statements.
Returning a 'Promise' value in 'promise.then()' makes promise chains.
Used memory and promises are not garbage collected
until finishing 'helpers.asyncToGenerator'.
* Update test
* Fix class inheritance in IE9 & IE10 (T3041)
Internet Explorer 9&10 do not support __proto__ at all, don't have
Object.setPrototypeOf(), but have Object.getPrototypeOf().
Because of this setting the prototype is not possible, which makes the
babelHelpers.inherits() function to set __proto__ although not supported.
Afterwards Object.getPrototypeOf() is used, but this one is not
respecting the "custom" property __proto__ that we set.
The solution is to check for __proto__ first and afterwards fallback to
Object.getPrototypeOf().
* Do the same logic in babel-helper-replace-supers
* Fix tests
* Extract creation of prototype nodes to small helper
This reverts commit 033681af8941d9678961f985c13e500c3c70f337, reversing
changes made to a2d66c0fc8ee58e82be3efd59173803e66dee3e0.
I brought you into this world, and I can take you out.
I previously tried an approach to scope bindings from var to scope but
it didn't catch all cases. This is evident in this bug:
https://phabricator.babeljs.io/T2892
Where even after transforming a const to a var we still get an error
that it's read-only.
This approach will go through and delete every existing let and const
binding and creates a new one with the kind "var"
Original PR: https://github.com/babel/babel/pull/2469. Seems this got
lost in the v6 changes.
- - -
Without this, the only way to replace the arrow function is to either
manually override its `node.body`, or duplicate the arrow:
```js
// Old
ArrowFunctionExpression: function (node) {
node.body = t.blockStatement(...);
// Or
return t.ArrowFunctionExpression(
node.params,
t.blockStatement(...),
node.async
);
}
// New
ArrowFunctionExpression: function() {
this.get("body").replaceWith(t.blockStatement(...));
}
```
Rather than repeating the original location when we exit a node, we need to restore the previous parent’s original line location, since the source map format denotes the start location.
