Nx Jest <rootdir> does not resolve properly in jest.preset.js

[anthony-b-dev]

Current Behavior

Currently, I have multiple jest.config.ts files in projects throughout my monorepo as a result of the automated library generation process. For some libraries, I have them nested one directory down to group the libraries by application. This results in the various jest.config.ts files being at different levels of the workspace hierarchy.

In jest.preset.js at the root level, I have the following:

const nxPreset = require('@nx/jest/preset').default;

module.exports = {
  ...nxPreset,
  /* TODO: Update to latest Jest snapshotFormat
   * By default Nx has kept the older style of Jest Snapshot formats
   * to prevent breaking of any existing tests with snapshots.
   * It's recommend you update to the latest format.
   * You can do this by removing snapshotFormat property
   * and running tests with --update-snapshot flag.
   * Example: "nx affected --targets=test --update-snapshot"
   * More info: https://jestjs.io/docs/upgrading-to-jest29#snapshot-format
   */
  snapshotFormat: { escapeString: true, printBasicPrototype: true },
  setupFiles: ['./jest.setup.ts'],
};

The last line gets me this error when I run nx test:

 NX   ● Validation Error:


        Module ./jest.setup.ts in the setupFiles option was not found.
               <rootDir> is: C:<\path\to\dir>\libs\shared\data

        Configuration Documentation:
        https://jestjs.io/docs/configuration

Because the jest.config.ts files in the libraries are at different levels, I can't hard code a relative path in the file.

Expected Behavior

The <rootdir> in jest.preset.js at the workspace root resolves to the workspace root every single time, not relative to the library root.

GitHub Repo

No response

Steps to Reproduce

1. Run npx create-nx-worspace with the Angular preset and choosing Jest as the test runner.
2. Run npm install @nx/nest --save
3. Run npx nx g @nx/angular:library libs/angular --importPath @testdemo/angular --routing=false --style none
4. Run npx nx g @nx/nest:library --directory=libs/nested/nestlb --importPath="@test/nestlib" --name=nestlib --simpleName
5. run npx nx run-many - t test

Nx Report

Node           : 22.13.1
OS             : win32-x64
Native Target  : x86_64-windows
npm            : 9.6.6

nx (global)            : 21.1.2
nx                     : 21.2.0
@nx/js                 : 21.2.0
@nx/jest               : 21.2.0
@nx/eslint             : 21.2.0
@nx/workspace          : 21.2.0
@nx/angular            : 21.2.0
@nx/cypress            : 21.2.0
@nx/devkit             : 21.2.0
@nx/esbuild            : 21.2.0
@nx/eslint-plugin      : 21.2.0
@nx/express            : 21.2.0
@nx/module-federation  : 21.2.0
@nx/nest               : 21.2.0
@nx/node               : 21.2.0
@nx/rspack             : 21.2.0
@nx/vite               : 21.2.0
@nx/web                : 21.2.0
@nx/webpack            : 21.2.0
typescript             : 5.8.3
---------------------------------------
Registered Plugins:
@nx/angular/plugin
---------------------------------------
Community plugins:
@ngrx/effects        : 19.2.1
@ngrx/entity         : 19.2.1
@ngrx/eslint-plugin  : 19.2.1
@ngrx/operators      : 19.2.1
@ngrx/router-store   : 19.2.1
@ngrx/schematics     : 19.2.1
@ngrx/signals        : 19.2.1
@ngrx/store          : 19.2.1
@ngrx/store-devtools : 19.2.1
angular-eslint       : 20.0.0
---------------------------------------
Cache Usage: 446.68 KB / 93.45 GB

Failure Logs

from the recreation steps:

       NX   ● Validation Error:


        Module ./jest.setup.js in the setupFiles option was not found.
               <rootDir> is:  C:\<\path\to\dir>\libs\nested\nestlb      

        Configuration Documentation:
        https://jestjs.io/docs/configuration

Package Manager Version

No response

Operating System

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

Additional Information

This issue started a few Nx versions ago, maybe with v18 or v19, I can't pinpoint exactly when. Before then, I was having no issues.

[leosvelperez]

Thanks for reporting this!

This is unrelated to Nx, and it's the expected Jest behavior for rootDir. From the Jest docs:

Default: The root of the directory containing your Jest config file or the package.json or the pwd if no package.json is found

The jest.preset.js is not the Jest config file that's run when running the test task for any given project. The config file is the specific jest.config.ts file in each project, so the rootDir is the directory of those config files.

To ensure the setup file in the preset correctly resolves to a file at that workspace root, regardless of the rootDir value, you can update your preset as follows:

const nxPreset = require('@nx/jest/preset').default;
const path = require('path');

module.exports = {
  ...nxPreset,
  /* TODO: Update to latest Jest snapshotFormat
   * By default Nx has kept the older style of Jest Snapshot formats
   * to prevent breaking of any existing tests with snapshots.
   * It's recommend you update to the latest format.
   * You can do this by removing snapshotFormat property
   * and running tests with --update-snapshot flag.
   * Example: "nx affected --targets=test --update-snapshot"
   * More info: https://jestjs.io/docs/upgrading-to-jest29#snapshot-format
   */
  snapshotFormat: { escapeString: true, printBasicPrototype: true },
  setupFiles: [path.join(__dirname, 'jest.setup.ts')],
};

[anthony-b-dev]

Crazy how tunnel vision works.
Thanks for the assist! It's working now!