[Bug]: yarn PNP does not pass NODE_PATH to node

[alamothe]

Self-service

• I'd be willing to implement a fix

Describe the bug

We have a TypeScript project. To run this project in production, we first build it, then execute it with node.

For the build, we use plain tsc (no Babel) because it is a simple backend service intended to run on Node.js.

Until now, we enjoyed absolute imports through NODE_PATH. The idea is simple:

• TypeScript compiler knows about absolute imports. However, tsc does not translate absolute imports to relative in generated js files, it leaves them as absolute.
• Our source is in src, build goes to build.

So far, we ran the service in production with:

cross-env NODE_PATH=build node --max-old-space-size=2048 build/index.js

This worked great so far.

However, with Yarn PNP NODE_PATH is not passed to node and absolute imports no longer work. We simply cannot start the service in production anymore after migrating to PNP.

Someone suggested to take a look at link: which is described here: https://yarnpkg.com/features/protocols#why-is-the-link-protocol-recommended-over-aliases-for-path-mapping. However, that works only for plain JavaScript workspaces. Linking src makes no sense since our build goes to build, src only contains TypeScript and we have no issues with compiling.

To reproduce

1. Create a TypeScript workspace and use absolute imports. TS has support for absolute imports through baseUrl setting.
2. Build the code using tsc. So tsconfig.json looks like this:

{
	"compilerOptions": {
		"target": "es2019",
		"module": "commonjs",
		"lib": ["es2019"],

		"outDir": "build",
		"rootDir": "src",
		"baseUrl": "./src",

Which is very standard for TS.

3. Try to run with:

cross-env NODE_PATH=build node --max-old-space-size=2048 build/index.js

Environment

System:
    OS: macOS 11.6.1
    CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  Binaries:
    Node: 14.17.1 - /private/var/folders/nt/2q41tjws39n1pds7hmbyxwvm0000gn/T/xfs-74a6c0d3/node
    Yarn: 3.1.0 - /private/var/folders/nt/2q41tjws39n1pds7hmbyxwvm0000gn/T/xfs-74a6c0d3/yarn
    npm: 6.14.13 - /usr/local/opt/node@14/bin/npm

Additional context

I believe the fix is simple: yarn should pass existing NODE_PATH to node (it can append whatever it needs)

[yarnbot]

Hi! 👋

This issue looks stale, and doesn't feature the reproducible label - which implies that you didn't provide a working reproduction using Sherlock. As a result, it'll be closed in a few days unless a maintainer explicitly vouches for it or you edit your first post to include a formal reproduction (you can use the playground for that).

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[arcanis]

NODE_PATH isn't compatible with PnP. You should instead define build via a link: dependency.

[merceyz]

As I said on Discord, it's not that it isn't passed to Node, it's that PnP doesn't use it.

While the link: protocol doesn't work for you imports using conditions would which can be tracked in #3843