Unable to resolve self-referring "subpath exports" from within a haste module

[kraenhansen]

Do you want to request a feature or report a bug?

I'd like to report a bug.

What is the current behavior?

Performing a self-referring subpath import (i.e. import "my-lib/some-sub-path") from within a package (in this example "my-lib") while the package is considered a haste module (included in watchFolders) I'm experiencing the following error:

Error: Unable to resolve module my-lib/subpath from /Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-lib/index.js: my-lib/subpath could not be found within the project.
> 1 | import { greeting } from "my-lib/subpath";
    |                           ^
  2 | console.log(greeting);
  3 |
    at ModuleResolver.resolveDependency (/Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/node-haste/DependencyGraph/ModuleResolution.js:138:15)
    at DependencyGraph.resolveDependency (/Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/node-haste/DependencyGraph.js:231:43)
    at /Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/lib/transformHelpers.js:156:21
    at resolveDependencies (/Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/DeltaBundler/buildSubgraph.js:42:25)
    at visit (/Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/DeltaBundler/buildSubgraph.js:83:30)
    at async Promise.all (index 0)
    at async visit (/Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/DeltaBundler/buildSubgraph.js:92:5)
    at async Promise.all (index 0)
    at async buildSubgraph (/Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/DeltaBundler/buildSubgraph.js:103:3)
    at async Graph._buildDelta (/Users/kraen.hansen/Projects/metro-self-ref-subpath-issue/my-app/node_modules/metro/src/DeltaBundler/Graph.js:157:22)

If the current behavior is a bug, please provide the steps to reproduce and a minimal repository on GitHub that we can yarn install and yarn test.

1. Clone the reproduction repository:

   git clone https://github.com/kraenhansen/metro-issue-1222
   

2. npm install (yarn doesn't create a symlink for the "../my-lib" dependency of "my-app").
3. npm test to observe the error above.

What is the expected behavior?

I would expect the subpath to resolved, just as if the my-app/index.js file is updated to import "my-lib/subpath" directly.

Please provide your exact Metro configuration and mention your Metro, node, yarn/npm version and operating system.

// metro.config.js
const path = require("path");

module.exports = {
  watchFolders: [
    path.resolve(__dirname, "../my-lib"),
  ],
  resolver: {
    unstable_enableSymlinks: true,
    unstable_enablePackageExports: true,
    enableGlobalPackages: false,
  }
};

• Metro v0.80.6
• node -v v20.10.0
• npm -v 10.2.3
• MacOS

Additional information

This bug feels related to #1128, as that was also dealing with subpath exports and haste modules.

[kraenhansen]

@robhogan you mentioned on #1136 (comment) that enableHastePackages is default-off from Metro 0.79, am I missing something obvious / context here?

This issue persists even when I explicitly set resolver.enableGlobalPackages = false.