externalized dependencies

[erwinheldy]

Why does the build output include syntax for importing packages in dependencies, whereas in the readme it says if packages in dependencies will be externalized

[privatenumber]

Perhaps you're missing what externalization does?

If not, what is your expected behavior?

Here are some docs on it:

• https://rollupjs.org/configuration-options/#external
• https://esbuild.github.io/api/#external
• https://webpack.js.org/configuration/externals/#root

ChatGPT explanation:
https://chat.openai.com/share/ad4981d9-854d-444b-b231-b2cf86dbc57c

[privatenumber]

Why's it not needed?

Impossible for me to determine given I don't know your input.

[erwinheldy]

Here's a simple example, the left side is the source while the right side is the build result.

Take a look at the cli.js file, line 4: import 'node:fs/promises'; I don't think it's needed because it's already imported in the index.js file, what do you think?

[erwinheldy]

For comparison, here is the result of using esbuild with the command:

esbuild src/index.ts --format=esm --platform=node --outdir=dist --bundle
esbuild src/cli.ts --format=esm --platform=node --outdir=dist

[privatenumber]

So JSYK the externalization logic is handled by Rollup, rather than pkgroll: REPL

The reason the imports are moved up is explained here:
https://rollupjs.org/faqs/#why-do-additional-imports-turn-up-in-my-entry-chunks-when-code-splitting

TLDR: it's a performance optimization so the JS engine can resolve dependencies faster

[erwinheldy]

Great, thanks for the explanation.