Here are some basic instructions for setting up eslint for for a project that uses ES5 and ES6.
The assumption is that you already have your own project, with its own package.json file.
Inspect the package.json file in this project, and copy all the devDependencies it contains into your own package.json file.
Then run npm install to retrieve the required npm packages.
This project includes a sample .eslintrc file.
To keep things simple, it uses airbnb rules as a base, and adds several rule modifications.
So you might like to check the "rules" section of .eslintrc to see if they match your requirements.
The package.json file in this project contains a very simple "eslint" script to run – it simply calls the eslint binary, with a single argument, which is the filespec for the JS files to lint.
Add this to the "scripts" section of your package.json file, and modify this filespec to match the files you want to lint.
Now you can run eslint against your files:
$ npm run eslint