Trying to use async/await in mocha - node.js

Question

I want to use async/await in mocha in order to make my tests. I have read many post, but I didn't find the solution. I have already install all the babel modules in order to transpiling the code, but it doesn't work.
Here is my code inside the "test" folder:
import test from 'mocha'
import 'babel-polyfill'
import { expect } from 'chai'
import { assert } from 'chai'
import utils from '../lib/utils'
describe('long number', function () {
it("Sample", mochaAsync(async () => {
var x = utils.longNums(0);
expect(x).to.equal(5000);
}))
})
Here is my package.json where I am using all the babel dependencies and plugins that I have read I have to install, and my test script where I suggest to mocha to use the babel transpiling
{
"name": "pos_lisa-test",
"version": "1.0.0",
"description": "pos lisa test",
"main": "index.js",
"scripts": {
"test": "mocha --compilers js:babel-core/register ./src/**/*.test.js"
},
"standard": {
"parser": "babel-eslint"
},
"babel": {
"presets": [
"es2015",
"react"
]
},
"keywords": [
"test"
],
"author": "Mauricio",
"license": "MIT",
"devDependencies": {
"babel-core": "^6.23.1",
"babel-eslint": "^7.1.1",
"babel-plugin-transform-async-to-generator": "^6.22.0",
"babel-preset-es2015": "^6.22.0",
"babel-preset-react": "^6.23.0",
"chai": "^3.5.0",
"mocha": "^3.2.0",
},
"plugins": [
"transform-async-to-generator"
],
"dependencies": {
"babel-polyfill": "^6.23.0"
}
}
And the error that I get is the following
it('should remove items that don\'t evaluate to true when passed to predicate function', async function () {
^^^^^
SyntaxError: missing ) after argument list
What I am doing wrong? In advance thanks a lot for your help

Answer 1

You have added "plugins": ["transform-async-to-generator"]" to the top level of your package.json, but it should be inside the "babel" section. Change it to:
"babel": {
"presets": [
"es2015",
"react"
],
"plugins": [
"transform-async-to-generator"
]
},

Answer 2

According to the Tao of Javascript, "Code flows in the moment, so knowledge is but a hint, like the map of a stream."
As of April, 2017, having the 'transform-async-to-generator' will actually cause problems.
As a more general note, every async function returns a promise, or casts its return value and exception to a promise. It is usually cleaner to test the promise and not have your test call await:
it('should have no drops left', () =>
ocean.listDrops().should.eventually.have.length(0));