babel-eslint custom parser and polyfill

[tulsileathers]

I'm trying to get Standard to ignore warnings for undefined variables due to using a babel polyfill (isomorphic-fetch specifically). I understand that you can use a custom parser to use experimental language features. I'm just not sure how to configure this. Can anyone give me an example of how to setup babel-eslint and standard to do this? I've searched but haven't been able to find good info. Thanks for any help.

[Flet]

Sorry for the late reply!

There is a bit of documentation on using babel-eslint:
https://standardjs.com/#how-do-i-use-experimental-javascript-es-next-features

Its also possible to avoid "variable not defined" errors in a couple ways:
https://standardjs.com/#i-use-a-library-that-pollutes-the-global-namespace-how-do-i-prevent-variable-is-not-defined-errors

I'm going to close this issue but please feel free to respond!

[feross]

For that library in particular (isomorphic-fetch) I recommend importing fetch explicitly and not relying on it's polyfill behavior. You want to be explicit about where fetch is coming from to satisfy standard. To do that, you have two options:

1. Use it directly (best)

const fetch = require('isomorphic-fetch')
fetch('http://example.com')

2. Use the global

require('isomorphic-fetch') /* global fetch */
fetch('http://example.com')

More info: #821

[karnavkumar]

use this global.fetch = require('node-fetch')