UMD centric build and distribution

[jeetiss]

Hello, folks! Thanks for a great library

I have started to use react-query and faced that webpack uses UMD build while package.json describes a module field that supports tree-shaking. so I dig into build/distribution process and found following problems

browser field

webpack's resolve module algorithm picks a more specific field from package.json (and other bundlers too), so webpack chooses UMD module from browser field on the default and that breaks tree-shaking

@tanstack/query-example-react-nextjs

Why browser field is specified in packages? Can I remove it?

I can find any reason for that, readme uses the full path to UMD bundle in CDN example
https://tanstack.com/query/v4/docs/installation#cdn

preserveModules

CJS build contains preserveModules enabled and that creates next problems

• all external modules are copied to the dist folder and shipped to npm, so all users download them twice and react-query has ginormous install size
• broadcast-channel have a browser field and preserveModules don't copy files specified by this field, so it creates issues like v4 of broadcast client, "cannot resolve '../../src/methods/node.js" #3965

I can't find any information on why preserveModules is here, can I remove it?

@DamianOsipiuk asked about this here, but nobody answered

external dependencies specified only for UMD

react-query install size becomes big because all external libraries are installed 4 times to node_modules ones for each type of distribution (esm cjs umd) and ones because dependence specified in package.json

Is it special or I can fix that?

https://packagephobia.com/result?p=%40tanstack%2Freact-query

[DamianOsipiuk]

Hi all of those issues should be fixed by #3892, yet it has not been released yet.
We first want to do a Prerelease and give it to community to test how it behaves with different bundlers and setups. And if everything will be ok, we will release it as a normal build.
This should happen soon.