Prevent Illegal invocation Error in webpack

[rockymeza]

I am using ES6 modules with webpack and I ran into an issue. My code was something like this:

import fetch from 'isomorphic-fetch';

fetch(url)
  // .then do stuff

which raised an Illegal invocation Error. This is the same error that happens when you do something like this:

log = console.log
log('hello'); // Error

I looked at the compiled code and it looked like this:

var _fetch = __webpack_require__(10);
var _fetch2 = _interopRequireWildcard(_fetch);

_fetch2['default'](url);

which is the problem because now the fetch function is called with a this value of the _fetch2 module. It is similar to doing the following:

var obj = {myFetch: fetch};

obj.myFetch(url); // Error

So I just made sure that fetch was bound to the window object on importing. This of course assumes that Function.bind exists or was polyfilled.

[crccheck]

Thanks. This was happening to me with browserify and babel in Chrome (but not Firefox) too. This was my workaround:

import fetch_ from 'isomorphic-fetch';
var fetch = fetch_.bind(undefined);

My jest tests remained happy with this hack too.

[beshanoe]

Thank you! Just ran into the same problem. Npm package should be updated ASAP

[rockymeza]

Thanks!

-rocky
2015年5月6日 下午3:25于 "Max" [email protected]写道：

Thank you! Just ran into the same problem. Npm package should be updated
ASAP

—
Reply to this email directly or view it on GitHub
#20 (comment)
.

[babsonmatt]

Thanks!

[zbyte64]

Life saver 👍

[khtdr]

just import the library and let it pollute the global/window namespace.

wrong:
import fetch from 'isomorphic-fetch'; fetch(...);

no error:
import 'isomorphic-fetch'; fetch(...);

[tomchentw]

My experience and workaround on this is simple: don't use import/require for polyfills.
Instead, use webpack.ProvidePlugin for them.

new webpack.ProvidePlugin({
  "fetch": "isomorphic-fetch",
});

[keithamus]

Just been bitten by this. It'd be great to get it merged @matthew-andrews 😄

[keithamus]

@matthew-andrews this one can be closed due to #27 being merged 😄

[matthew-andrews]

Released in v2.1.1.