issues when using rxjs/fetch in create-react-app or webpack

[kambing86]

Bug Report

Current Behavior

the default behaviour of using

import { Observable } from "rxjs";

it will be using the source file in ./node_modules/rxjs/_esm5/index.js because of the module defined in ./node_modules/rxjs/package.json

but if we are using some other stuffs like

import { fromFetch } from "rxjs/fetch";

it will be using the source file in ./node_modules/rxjs/fetch/index.js

this is causing a lot of bugs which I filed it here #4820

I have to use

import { fromFetch } from "rxjs/_esm5/fetch";

then everything works fine

Reproduction
https://github.com/kambing86/test-from-fetch
fix repo https://github.com/kambing86/test-from-fetch/tree/fix/import-fromFetch

Expected behavior
should be using just one type of source?

Environment

• Runtime: Node 10 / 12, Chrome 76
• RxJS version: 6.5.2
• (If bug is related) Loader, build configuration: create-react-app
• built in macOS High Sierra / WSL in Windows10

[kambing86]

it seems like using rxjs/operators is fine, most likely because they are just pure functions without state

import { finalize, mergeMap, share } from "rxjs/operators";

but fromFetch is returning the Observable class which is stateful, and this causes a lot of weird issues

[cartant]

@benlesh It seems likely that the problem is related to fetch not being included here:

rxjs/.make-packages.js

Lines 135 to 140 in 3881723

	fs.writeJsonSync(PKG_ROOT + 'package.json', rootPackageJson, {spaces: 2});
	fs.copySync('src/operators/package.json', PKG_ROOT + '/operators/package.json');
	fs.copySync('src/ajax/package.json', PKG_ROOT + '/ajax/package.json');
	fs.copySync('src/webSocket/package.json', PKG_ROOT + '/webSocket/package.json');
	fs.copySync('src/testing/package.json', PKG_ROOT + '/testing/package.json');
	fs.copySync('src/internal-compatibility/package.json', PKG_ROOT + '/internal-compatibility/package.json');

[kambing86]

thanks @cartant for pointing out the root cause, I tried to fix it in my local and it works

create a PR for this #5001