Ethers and Rollup

Hello,

I am struggling to get ethers.js to work with rollup.

The specific error that I am encountering in browser is:

Uncaught SyntaxError: The requested module './../../../bn.js/lib/bn.js' does not provide an export named 'default'

Here is a repo to reproduce the error: https://github.com/GradientCap/Graph

Rollup config: https://github.com/GradientCap/Graph/blob/main/rollup.config.js

I’ve tried setting mainfields and using the commonjs plugin configuration from the ethers repo to no avail.

Any help would be appreciated.

[veikkoeeva]

I’ll add here that I did just a quick experiment by going to node_modules and bn.js package where I patched package.config to have "module": "lib/bn.esm.js", created a file with that name and copy-pasted the contents of bn.js to there and echanged the module export to export default { BN } and it compiled. Another idea could something like import BN from "bn.js"; -> import * as _BN from "bn.js"; and doing it to all modules that import like that, but it wouldn’t work on runtime.

There’s more links in the SO thread, but it looks to me RollupJS checks module field and due to recent changed it may be @rollup/plugin-commonjs does not catch the CJS module exports in the files and so consequently they are not transpiled to ESM ones in expeced format.

I am not sure how laborious would it be to turn the file into ES modules locally and add default exports, but maybe I try later next week. Looking quickly at packages, most are maintained by @ricmoo already or have a TS/Rollup builds that just do not provide ES builds yet. 😃 (As an aside, it appears to be web advocates from communities like lit.dev, open-wc etc. note to provide ES6 builds with modern code and let users to transpile if they need specific polyfills etc.)

[ricmoo]

Once the beta of v6 is out, I would love wools to experiment with various bundlers. I personally only use rollup (you can check out the various rollup configs in the project for some ideas if you are having problems) and webpack as part of the ReactNative tests.