Webpack: Cannot destructure property `curry` of 'undefined' or 'null'

Question

After compiling my application using webpack & babel-loader for the browser, the following error appears right off the bat before the main function starts:

Uncaught TypeError: Cannot destructure property `curry` of 'undefined' or 'null'.
    at Object../node_modules/@qzdio/f/lib/combinators/sync.js (index-c1596672f4.js:formatted:268)
    at n (runtime-74c3f0da77.js:formatted:10)
    at Object../node_modules/@qzdio/f/lib/combinators/index.js (index-c1596672f4.js:formatted:251)
    at n (runtime-74c3f0da77.js:formatted:10)
    at Object../node_modules/@qzdio/f/lib/index.js (index-c1596672f4.js:formatted:723)
    at n (runtime-74c3f0da77.js:formatted:10)
    at Object../dist/graph/visualizer/src/index.js (index-c1596672f4.js:formatted:9)
    at n (runtime-74c3f0da77.js:formatted:10)
    at window.webpackJsonp (runtime-74c3f0da77.js:formatted:26)
    at index-c1596672f4.js:formatted:1

The faulty code is the ES5 transpilation of the following:

import R from 'ramda';
const { curry } = R;

// I :: a -> a
const I = (x) => x;
...

Where the said code is from a private functional library that relies on ramda and bluebird. The library is used and working under Node.js 8.9.1.

The webpack config used is straight up from philipwalton's webpack-esnext-boilerplate (great to start with :D)

Versions:

babel-cli: ^6.26.0,
babel-loader: ^7.1.2,
webpack: ^3.8.1,
Browser: Google Chrome Version 62.0.3202.89 (Official Build) (64-bit),
Node.js: 8.9.1,
npm: 5.5.1

What is the source of the error and how can it be resolved?

Cheers ✨

Both of them are valid permutations of the line yes, but in order to test them in webpack I would have to commit to the library, then push a patched version on npm. I can guarantee you that both work in a node environment however, since I have these exact lines in other files of the library and as said earlier the library loads correctly in node. My guess is that this is more of a configuration/transpilation issue from the webpack viewpoint. But if you do insist I will make the changes — Philippe Hebert, Nov 16 '17 at 15:54
Updating to `import R from 'ramda';` and then using `R.curry` resolves to the same error; `import { curry } from 'ramda'` seems to do the trick. @dzm any idea why? — Philippe Hebert, Nov 16 '17 at 19:24

score 2 · Accepted Answer · answered Nov 16 '17 at 19:32

2

You have to use import { curry } from 'ramda'. You can see here how rambda is exporting it's modules. It doesn't export the ramda module itself, but rather the individual functions.

If you want to access additional methods, you can use this for example:

import { curry, addIndex, clone } from 'ramda'

answered Nov 16 '17 at 19:32

dzm

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That's really interesting. Goes to wonder why I've always used the method outlined in the original post without any issue. But yes you are right, and this solves the issue! – Philippe Hebert Nov 16 '17 at 19:42

score 1 · Answer 2 · answered Nov 16 '17 at 19:36

1

If you really want all the exported values in one object, you can do the following

import * as R from 'ramda';
const { curry } = R;

answered Nov 16 '17 at 19:36

Maluen

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Webpack: Cannot destructure property `curry` of 'undefined' or 'null'

Versions:

2 Answers2