How to use with Jest?

I’m trying to use your package with Jest to test React project but I can’t get it to work, below is my Jest configuration.

// jest.config.js
module.exports = {
  // rest of config...
  setupFilesAfterEnv: ['./tests/setup.ts']
};

// tests/setup.ts
import appRootPath from 'app-root-path';
import tsConfig from '../tsconfig.json';
import tsConfigPaths from 'tsconfig-paths';

let cleanup: () => void;

beforeAll(() => {
  cleanup = tsConfigPaths.register({
    baseUrl: appRootPath.path,
    paths: tsConfig.compilerOptions.paths
  });
});

afterAll(() => {
  cleanup();
});

it keeps throwing errors like “Cannot find module ‘@views/components/error-boundary’ from ‘App.tsx’”

any ideas on how to use it with Jest, keep in mind that Jest doesn’t support the --require flag.

[geersch]

@AhmedMKamal, you don’t need to use that package.

If you use the baseUrland paths options in your tsconfig file, you must make sure to also configure the moduleNameMapper option in your Jest config.

tsconfig.json

{
  "compilerOptions": {
    "baseUrl": "./",
    "paths": {
      "@app/*": ["src/*"]
    }
  }
}

jest.config.json

{ 
  "moduleNameMapper": {
    "^@app/(.*)$": "<rootDir>/$1"
  }
}

You’ll need to map the configuration to the Jest config format, which uses regular expressions. ts-jest provides a helper to transform the mapping from tsconfig to Jest config format, but it you use it you need the .js version of the config file.

jest.config.js

const { pathsToModuleNameMapper } = require('ts-jest/utils');
const { compilerOptions } = require('./tsconfig');

module.exports = {
  //...
  moduleNameMapper: pathsToModuleNameMapper(compilerOptions.paths , { prefix: '<rootDir>/' } )
};

The module that you use basically does the same thing as the pathsToModuleNameMapper helper offered by ts-jest. But if you can use ts-jest’s helper, then I’d remove the extra dependency and use it instead.

More information can be found here:

https://kulshekhar.github.io/ts-jest/user/config/

[aelbore]

@geersch you can try to install alias-hq here’s the docs https://github.com/davestewart/alias-hq/blob/master/docs/integrations.md