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undefined is not a function (evaluating 'babelHelpers.typeof(obj)') using nes library #8074
Description
Hey there!
I'm trying to use nes library with react-native with no success.
I included nes in a fresh react-native project like this:
import React, { Component } from 'react';
import {
AppRegistry,
StyleSheet,
Text,
View
} from 'react-native';
import { Client as NesClient } from 'nes/client';But I'm getting the following error:
And after trying to add nes in one or another way I came out with this:
If I modify the file nes/dist/client.js like this:
var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol ? "symbol" : typeof obj; };
(function (root, factory) {
// $lab:coverage:off$
/*
if ((typeof exports === 'undefined' ? 'undefined' : _typeof(exports)) === 'object' && (typeof module === 'undefined' ? 'undefined' : _typeof(module)) === 'object') {
module.exports = factory(); // Export if used as a module
} else if (typeof define === 'function' && define.amd) {
define(factory);
} else if ((typeof exports === 'undefined' ? 'undefined' : _typeof(exports)) === 'object') {
exports.nes = factory();
} else {
root.nes = factory();
}
*/
module.exports = factory();
// $lab:coverage:on$
})( /* $lab:coverage:off$ */typeof window !== 'undefined' ? window : global /* $lab:coverage:on$ */, function () {
// ...
});Everything works perfectly, But I can't totally understand with running _typeof({}); throws the same error as the image above.
Also, if I open the remote debugger (with the above "solution") get the following error:
> node -v
v5.9.0
> react-native -v
react-native-cli: 0.2.0
react-native: 0.26.3
Activity
[-]babelHelpers.typeof is not a function using nes[/-][+]undefined is not a function (evaluating 'babelHelpers.typeof(obj)') using nes library[/+]satya164 commentedon Jun 12, 2016
Seems the nes module is pre-compiled with babel using the es2015 preset.React Native uses a different babelHelpers file which might be causing issues. The only workaround I know as of now is to fork React Native and replace it's babelHelpers file with a standard babelHelpers file as documented here - https://github.com/facebook/react-native/blob/235b16d93287061a09c4624e612b5dc4f960ce47/packager/react-packager/src/Resolver/polyfills/babelHelpers.js#L13
I had this issue with one of our own modules earlier and ended up switching that module to use the
react-nativepreset so that we don't have to maintain a fork of React Native.The proper fix will be to add the ability to specify a babelHelpers file to react-native packager. PRs are welcome.
byoigres commentedon Jun 13, 2016
Well, I ended using this solution and it works perfectly.
satya164 commentedon Jun 13, 2016
Awesome. I had actually used that solution in past, but it broke with RN upgrade.
MoOx commentedon Sep 21, 2016
I got a similar error multiple times while I was starting with react-native on the last 2 days.
First I previously add a development section in my babel conf where es2015 where using, so boom. Took me a while to understand that, even with all those errors.
After that, (I now launch
npm startwithNODE_ENV=nativeto avoid babel using development section - which is the default behavior), I used react-router-native (which rely on react-router) which rely on babel-preset-stage-1.Having this
babelHelpers.typeof is not a functionerror is really not explicit.I am still new with react-native, but I saw that some times, errors are caught and displayed with nice explanations (like when using react/react-dom - which is a good thing).
Don't you think this generic error could be caught and enhanced to prevent people wasting time on this, like I just did for a couple of hours?
lacker commentedon Nov 29, 2016
@MoOx It seems like a good idea to add an extra warning when this happens. Interested in sending a pull request? ;-)
Otherwise, it seems like this is an issue with a known workaround, rather than an outstanding bug, so I am going to close this issue. I think the right fix is to stop transpiling npm modules but for now there are workarounds.