NPM Test - No Tests Found

[svencowart]

Is this a bug report?

Yes

Did you try recovering your dependencies?

Yes

Which terms did you search for in User Guide?

testing, test configuration, jest, jest configuration, overriding pattern

Environment

System:
OS: macOS 10.14.3
CPU: x64 Intel(R) Core(TM) i7-8850H CPU @ 2.60GHz
Binaries:
Node: 10.15.1 - /usr/local/bin/node
npm: 6.8.0 - /usr/local/bin/npm
Browsers:
Chrome: 72.0.3626.121
Safari: 12.0.3
npmPackages:
react: ^16.8.4 => 16.8.4
react-dom: ^16.8.4 => 16.8.4
react-scripts: ^2.1.8 => 2.1.8
npmGlobalPackages:
create-react-app: 2.1.8

Steps to Reproduce

(Write your steps here:)

1. mkdir node_modules
2. cd node_modules
3. create-react-app test
4. cd test
5. npm test
6. (optional) enter "a" after test runner is up.

Expected Behavior

The test in App.test.js should have ran.

Actual Behavior

Step 5 output: No tests found related to files changed since last commit.
Step 6 output:

No tests found
No files found in /Users/svencowart/dev/node_modules/test.
Make sure Jest's configuration does not exclude this directory.
To set up Jest, make sure a package.json file exists.
Jest Documentation: facebook.github.io/jest/docs/configuration.html
Pattern:  - 0 matches

PS: I totally understand that it cannot find any tests because the project is within the node_modules folder; however, this is something beyond my control. It seems though if I run npm test within a project regardless of what parent directory is, it should find those tests but ignore the node_modules that are child directories of the project.

[bugzpodder]

This is probably a limitation with Jest: jestjs/jest#1995
Regardless, even this can be worked around, I am just not seeing how this feature would be useful to anyone else. I recommend tweaking your setup, or tweaking the way how your project runs tests.

[svencowart]

I was able to resolve this issue by using react-app-rewired and configuring jest inside of package.json.

For anyone with similar issues, here is what I did:
Configuring jest within package.json: (make sure the path you specify is the path starting one directory down from the node_modules folder that contains your react project and points to the directory containing your application - e.g. my application is inside of node_modules/my-application/client so the past I add is my-application/client.)

"jest": {
  "haste": {
    "providesModuleNodeModules": [
      "my-application/client"
    ]
  }
}

The contents of my config-overrides.js file:

module.exports = {
  webpack: (config, env) => config,
  jest: config => {
    config.testPathIgnorePatterns = [];
    config.transformIgnorePatterns[0] = `<rootDir>${
      config.transformIgnorePatterns[0]
    }`;
    return config;
  },
  devServer: configFn => configFn,
  paths: (paths, env) => paths,
};

@bugzpodder It seems the real issue is that react-scripts does not support changing the jest configuration for testPathIgnorePatterns and transformIgnorePatterns so I need to rely on react-app-rewired for such changes. However, this could be very intentional so I'll close this issue since my original ticket is resolved.