Error [ERR_REQUIRE_ESM]: Must use import to load ES Module

In Node.js v14, I got this error.

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: /Users/salty/Documents/src/youtu-bu/node_modules/ky-universal/index.js
require() of ES modules is not supported.
require() of /Users/salty/Documents/src/youtu-bu/node_modules/ky-universal/index.js from /Users/salty/Documents/src/youtu-bu/packages/youtu-bu-sakagura/.next/server/pages/index.js is an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which defines all .js files in that package scope as ES modules.
Instead rename /Users/salty/Documents/src/youtu-bu/node_modules/ky-universal/index.js to end in .cjs, change the requiring code to use import(), or remove "type": "module" from /Users/salty/Documents/src/youtu-bu/node_modules/ky-universal/package.json.

Could you tell me why do you use "type": "module" in package.json?

[sindresorhus]

I think you could have easily Googled the error and figured this out yourself.

It’s also explained in the release notes: https://github.com/sindresorhus/ky-universal/releases/tag/v0.9.0

[sindresorhus]

@RXminuS I can understand the situation is annoying. Yes, I could have been more helpful in the issue comment, but I get many issues like this every day where the poster did zero effort in Googling or debugging stuff themselves. It’s both time consuming and demotivating. ky-universal is a 100% valid ESM package. The fact that Next.js cannot handle ESM is not really something I can control or something I should be obliged to answer support questions about. ESM has been in development for 10 years. We all knew it was coming. Webpack and Next.js could have better prepared for this. In the end, you are the one that chose to use Next.js, with all the hidden complexity that entails.

That being said, I’m happy to document workarounds for Next.js in https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c (comment on that gist with any working workarounds)