@types/zen-observable missing in dependencies list

[onichandame]

Problem

This lib is compiled to use @types/zen-observable as a shadow dependency. This won't be a problem in node_modules as @apollo/client -> zen-observable-ts -> @types/zen-observable.

But it throws when used with yarn v2 PnP where shadow dependency is strictly forbidden. An example output is:

../../.yarn/__virtual__/@apollo-client-virtual-65fb8a2b1f/0/cache/@apollo-client-npm-3.4.8-69b6059fd9-07e4f32545.zip/node_modules/@apollo/client/link/utils/fromError.d.ts:1:23 - error TS2688: Cannot find type definition file for 'zen-observable'.
/// <reference types="zen-observable" />

There are dozens of such errors. After a quick glance at the code, I found that the source code does not use the shadow dependency at all, it is solely a result of the ts compilation.

Workaround

yarn v2 provides a way to patch the deps of packages:

# .yarnrc.yml
packageExtensions:
  "@apollo/client@*":
    dependencies:
      "@types/zen-observable": "*"

Solution

As simply patching @apollo/client with a dependency eradicates the errors, the straight forward solution would be fixing the dependencies list.

I have found a relating issue #2405 . It was once fixed but now on master branch the dependencies are removed again.

[benjamn]

@onichandame I would very much hope https://github.com/apollographql/zen-observable-ts (a package we control) can abstract away these concerns without help or oversight from Apollo Client.

From your perspective, is there anything zen-observable-ts could be doing to prevent tsc from generating these /// <reference types="zen-observable"/> lines when compiling packages (like @apollo/client) that merely depend on zen-observable-ts and don't know/care about zen-observable?

It would be shame to require any package using zen-observable-ts also to run npm i @types/zen-observable, especially since the zen-observable-ts package has @types/zen-observable in the dependencies section of its package.json, so @types/zen-observable is guaranteed to be installed (even in production) when zen-observable-ts is installed.

What more can zen-observable-ts do here?

[onichandame]

I am not sure how and why the reference line is generated. will look into it after work.

[benjamn]

I wonder if there's a way we could just remove @types/zen-observable from the picture, maybe by internalizing those types within zen-observable-ts. I'll keep looking into to it.

[benjamn]

I think that idea might work! apollographql/zen-observable-ts#152

[benjamn]

@onichandame Can you try with @apollo/[email protected] (just published)? When I install that version, I no longer see the comments

/// <reference types="zen-observable" />

so I'm hopeful your issue will be solved.

[onichandame]

My project has switched from PnP to node modules for ESM support, so I cannot reproduce the error in the original project.

Having tested @apollo/[email protected] in a fresh new project with PnP enabled, it worked!
Thanks a lot for your quick action :P