Nx jest resolver might resolve the same file as different modules

[yjaaidi]

Current Behavior

Given the following conditions:

• adding a tsconfig.spec.json at the root of the workspace
• using tsconfig paths with deep import (e.g. "@demo/stuff/*": ["apps/demo/stuff/*"]) + a barrel export in index.ts

then importing the same symbol from the @demo/stuff and @demo/stuff/something will produce different symbols:

import { Something } from '@demo/stuff';
import { Something as DeepSomething } from '@demo/stuff/something';

Something === DeepSomething; // false

This can break many things (e.g. dependency injection, variables holding global variables / counters etc...)

It seems that the problem comes partially from Nx jest resolver:

nx/packages/jest/plugins/resolver.ts

Line 76 in 2f9060e

compilerSetup = compilerSetup || getCompilerSetup(options.rootDir);

1. when the files are resolved by jest (e.g. test-setup.ts), the rootDir is undefined
2. if tsconfig.spec.json does exist in the workspace root, getCompilerSetup() works instead of crashing and resolves the configuration from the root config which resolves TS rootDir to . instead of the absolute path to the library.
3. from there, all modules are resolved with a relative path starting from the workspace root instead of an absolute path and this seems to cause the issue here.

Suggested solutions

A. While I still don't understand why rootDir is undefined, throwing an error in getCompilerSetup() if rootDir is undefined is a better option than mistakenly using tsconfig.spec.json from the workspace root as it solves this issue.
B. We could improve the heuristics of finding the "right" tsconfig.

Expected Behavior

Modules should be resolved consistently no matter what the configuration is.

GitHub Repo

https://github.com/yjaaidi/experiments/tree/repro/nx-jest-resolver

Steps to Reproduce

1. clone repro from https://github.com/yjaaidi/experiments/tree/repro/nx-jest-resolver
2. nx test demo

Nx Report

>  NX   Report complete - copy this into the issue template

   Node   : 21.4.0
   OS     : darwin-arm64
   pnpm   : 8.12.0
   
   nx                 : v17.2.5
   @nx/js             : v17.2.5
   @nx/jest           : v17.2.5
   @nx/linter         : v17.2.5
   @nx/eslint         : v17.2.5
   @nx/workspace      : v17.2.5
   @nx/angular        : v17.2.5
   @nx/cypress        : v17.2.5
   @nx/devkit         : v17.2.5
   @nx/eslint-plugin  : v17.2.5
   @nx/playwright     : v17.2.5
   @nrwl/tao          : v17.2.5
   @nx/web            : v17.2.5
   @nx/webpack        : v17.2.5
   typescript         : 5.2.2

Failure Logs

No response

Package Manager Version

No response

Operating System

• macOS
• Linux
• Windows
• Other (Please specify)

Additional Information

No response

[github-actions]

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