@babel/plugin-transform-async-to-generator

In

var _asyncToGenerator = function (fn) {
  ...
};
var foo = _asyncToGenerator(function* () {
});

Out with options

var Bluebird = require("bluebird");
var foo = Bluebird.coroutine(function*() {
});

Without options:

{
  "plugins": ["@babel/plugin-transform-async-to-generator"]
}

{
  "plugins": [
    [
      "@babel/plugin-transform-async-to-generator",
        "module": "bluebird",
      }
    ]
  ]
}

require("@babel/core").transformSync("code", {
  plugins: ["@babel/plugin-transform-async-to-generator"],
});

When using await with non-promise values, Bluebird will throw “Error: A value was yielded that could not be treated as a promise”. Since Babel cannot automatically handle this runtime error, you should manually transform it to a promise.

async function foo() {
-  await 42;
}