Auto imports not working properly with RxJS 7 beta

[benlesh]

• VS Code Version: any
• OS Version: any

Steps to Reproduce:

1. Add rxjs@7.0.0-beta.12 to a project
2. type concatMap and check the possible auto-import locations
3. It should show rxjs/operators as the correct import location. Instead it shows rxjs/dist/types/operators.

Does this issue occur when all extensions are disabled?: Yes

This comes from an issue reported on the RxJS repository here: ReactiveX/rxjs#6067

Apparently, neovim users don't experience this issue, so it leads me to believe it's not the configuration of the package.

[mjbvz]

Having trouble getting any auto imports for map to show up:

import { interval } from "rxjs";

interval(100).pipe(
    map()
)

There are no auto imports:

Any extra steps required while setting up the project?

[voliva]

Yes, first you need to import something from rxjs/operators in another file of the same project. This usually hints that rxjs/operators also has exports.

The issue in the other files (where it hasn't been manually imported), then VSCode suggests rxjs/dist/types/operators instead.

My environment, btw:

• VSCode: 1.53.2
• Node: 12.18.3
• Typescript: 4.1.5

[Toliak]

Reproduced for me with TS 4.2.3.

Yes, There is no suggestions to import concatMap (another bug, I think it is #30033), until there is no .ts files with rxjs/operators import.

After adding mentioned .ts file, for example:

import {} from 'rxjs/operators'

The bug appears:

OS Version: Linux manjaro 5.4.97-1-MANJARO

Code Version:

1.53.1
5d424b828ada08e1eb9f95d6cb41120234ef57c7
x64

All extensions are disabled.

[voliva]

I've been digging a bit around TSServer and am I correct the fix might be in moduleSpecifiers.ts#tryGetModuleNameAsNodeModule?

As far as I can see, that function receives a declaration file path (e.g. {absolutePath}/node_modules/rxjs/dist/types/index.d.ts or {absolutePath}/node_modules/rxjs/dist/types/operators/index.d.ts) and tries to resolve it to a node module name by looking at package.json, correctly identifying rxjs/dist/types/index.d.ts as rxjs but failing to identifiy rxjs/dist/types/operators/index.d.ts

Would it be possible to update this file to also consider subfolders?

[andrewbranch]

This is caused by the highly unusual package organization present in RxJS 7. node_modules/rxjs/operators is empty except for a package.json (not the root package.json) whose entrypoints point back outside of that folder (to dist/types/operators/index.d.ts for types). While that works fine for module resolution, it’s hard to imagine how we should be able to come up with that from scratch. When we generate a module specifier for a module file inside node_modules, we walk up the directory tree from that file looking at package.json files we see along the way, and see if their types/main fields point to that file. If so, we can use a short path to the directory of that package.json. But when we start at node_modules/rxjs/dist/types/operators/index.d.ts, we of course never see node_modules/rxjs/operators/package.json in that traversal. From the perspective of the module specifier resolver, we have absolutely no indication that some other directory would contain a match for that file. I’m not sure there’s anything TypeScript can reasonably do here.