Migrate deprecated 'assert' import syntax, bump to Node 18.20

[fatso83]

Description

This fixes #35825 by ensuring that yarn start works. Currently this breaks on both Node 20 and 22 due to scripts using a mix of syntax only supported by either version.

Motivation

I wanted to contribute a tiny fix and this made it impossible to check the result by firing up yarn start (it still does, by the way, as the proxy feature doesn't seem to work on my Mac). Now, at least, I can run tests and linting.

Additional details

• Remove deprecated 'assert' import syntax in favor of 'with'
• Specify engines field to minimum Node 22 for experimental 'import ...with' support

Related issues and pull requests

Fixes #35825

Background
nodejs/node#51622

Note that with is already unflagged in 20 and 21 (and in 18 right now it just doesn't exist, not even behind a flag).

[fatso83]

After seeing that this PR failed in the Github workflow due to .nvmrc setting the Node version to 18.20.4, I installed that locally, and that worked. I could revert the engines change, but still, there is no documentation on which Node version to use in the docs (not even mentioning NVM), so that does not really fix anything. Also, Node 18 is reaching EOL in these days and it's about time to update the version anyway 😄

I'll await some feedback. I can for instance include a reference in the contributor docs to look at .nvmrc for the supported version.

[bsmth]

Thanks for opening this one. We have a tracker for moving to Node 20 in MDN repos here: mdn/mdn#521

[fatso83]

According to the linked issue no one should start working on this yet. Should I then just revert all nvmrc and package.json changes, but keep the rest and explicitly set the engine to ">=18.18.0, < 19.0.0" to avoid issues such as the ones I got?

I could also make a mention in the contributing.md docs about referring to .nvmrc for which Node version to use?

[caugner]

Should I then just revert all nvmrc and package.json changes, but keep the rest and explicitly set the engine to ">=18.18.0, < 19.0.0" to avoid issues such as the ones I got?

We strive to support all current and future LTS versions of Node.js, and currently also support the active LTS version 18. So we don't want to restrict the engine to < 19.0.0.

The good news is that Node 18.20.0 added support for import attributes, so we should require >=18.20.0 instead and migrate the deprecated assert syntax.

@fatso83 Can you update your PR accordingly? 🙏

[fatso83]

Updates done

[caugner]

Thanks @fatso83!