Should mark package.json dependencies as external by default

[mesqueeb]

I'm just thinking that for the es and cjs builds, it should mark all package.json dependencies as external by default:

const pkg = require('../package.json')
const external = Object.keys(pkg.dependencies || [])

Not doing so will include all dependencies as part of the resulting built files. This gives webpack of developers who import your package a harder time eliminating duplicate dependencies.

Please note that passing them as "external" in rollup, they don't need to be added as peer dependency. They will be installed automatically when a dev does npm i or yarn add on your package.

[mesqueeb]

Another benefit to doing so is that it becomes clear on bundlephobia what is taking up space:

This is the example before marking dependencies as external:

This is the same package after marking dependencies as external:

[rstoenescu]

Of course. Please PR it.

[mesqueeb]

@rstoenescu cool thanks! I'll PR asap!!

[hawkeye64]

Love this idea! Thanks Luca! @mesqueeb

[hawkeye64]

I wonder if this would accomplish something similar: rollup-plugin-peer-deps-external - https://www.npmjs.com/package/rollup-plugin-peer-deps-external

[hawkeye64]

Ok, I am not so thrilled with this concept any longer. I tried it out on a few projects with bad results. The issue I had was using an external dependency as a mix-in. This caused rollup to not bundle the dep, which would then require the user to have a way to use it with UMD and that mix-in does not have a UMD equivalent.

[mesqueeb]

@hawkeye64 the idea is to set all dependencies as external, but only for es and cjs builds as I mentioned.

For UMD build, as you mention, it's better that all dependencies do get bundled with the result. 😉

[hawkeye64]

Ah, I see. That would be better. Still looking forward to your PR then. :)