For a library written in ES6/7, I want to compile (to ES5) the library to a dist/ folder. I also want to run the tests (written in ES6/7) for this lib.
My dev dependencies look like this (package.json):
"devDependencies": {
"@babel/cli": "^7.4.4",
"@babel/core": "^7.4.5",
"@babel/preset-env": "^7.4.5",
"@babel/register": "^7.4.4",
"chai": "^4.2.0",
"mocha": "^6.1.4",
"sinon": "^7.3.2"
},
My build and test scripts looks like this (package.json):
"scripts": {
"test": "mocha --require @babel/register",
"build": "babel src -d dist --presets=@babel/preset-env"
},
Running npm run build
works well. The dist/ folder gets populated with transpiled files.
Running npm run test
does not seem to work - this is my problem.
> mocha --require @babel/register
/Users/dro/Repos/lib/node_modules/yargs/yargs.js:1163
else throw err
^
ReferenceError: regeneratorRuntime is not defined
Initially I got an import error, which was resolved by adding .babelrc file.
Below is my .babelrc file content.
{
"presets": ["@babel/preset-env"]
}
I was reading about regeneratorRuntime
and it got me to this link about babel-polyfill where they explain I shouldn't need that polyfill.
This will emulate a full ES2015+ environment (no < Stage 4 proposals) and is intended to be used in an application rather than a library/tool.
What is needed to set this up properly?
I am not using webpack.
Testing in ES6 with Mocha and Babel 7. Look here: https://dev.to/bnorbertjs/my-nodejs-setup-mocha--chai-babel7-es6-43ei or http://jamesknelson.com/testing-in-es6-with-mocha-and-babel-6/
npm install --save @babel/runtime
npm install --save-dev @babel/plugin-transform-runtime
And, in .babelrc, add:
{
"presets": ["@babel/preset-env"],
"plugins": [
["@babel/transform-runtime"]
]
}