[fenomas]

> You can have an automated tool, usually a plugin for your front-end bundler, compile a pretty good notice file for you,

I think the tl;dr is that this is feasible but not common, and there's no single widely-used default way of doing it.

E.g. Many packages put their copyright/license info in special inline comments (using /! ... / tags), and every minifier I've used keeps such tags by default. But including these tags in your bundles can be undesirable - if a dependency has: /! Copyright foo@bar / without specifying the package name, then your bundle will appear to be entirely (c) that author.

OTOH the huge majority of projects do include a valid license identifier in a package.json tag (since npm complains if you don't). But I don't think there's any widely-used default way of generating a good licenses declaration from them.