05b22d2597
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`).
@babel/plugin-transform-async-to-generator
Turn async functions into ES2015 generators
In Babel 7,
transform-async-to-module-methodwas merged into this plugin
Example
In
async function foo() {
await bar();
}
Out
var _asyncToGenerator = function (fn) {
...
};
var foo = _asyncToGenerator(function* () {
yield bar();
});
Out with options
Turn async functions into a Bluebird coroutine
var Bluebird = require("bluebird");
var foo = Bluebird.coroutine(function* () {
yield bar();
});
Installation
npm install --save-dev @babel/plugin-transform-async-to-generator
Usage
Via .babelrc (Recommended)
.babelrc
Without options:
{
"plugins": ["@babel/plugin-transform-async-to-generator"]
}
With options:
{
"plugins": [
["@babel/plugin-transform-async-to-generator", {
"module": "bluebird",
"method": "coroutine"
}]
]
}
Via CLI
babel --plugins @babel/plugin-transform-async-to-generator script.js
Via Node API
require("@babel/core").transform("code", {
plugins: ["@babel/plugin-transform-async-to-generator"]
});