Paths not being resolved. Cannot find module X from Y

Issue: Doesn’t seem to work with tsconfig.json -> compilerOptions.paths.

Expected behaviour: I would like ts-jest to handle the relationship to files as specified with tsconfig.json -> compilerOptions.paths.

Link to a minimal repo that reproduces this issue: It’s closed source, but what I can do is give you an example.

tsconfig.json

{
	"compiledOptions": {
		"emitDecoratorMetadata": true,
		"experimentalDecorators": true,
		"module": "es2015",
		"moduleResolution": "node",
		"target": "es2017",
		"lib": ["dom", "es2015", "es2016", "es2017"],
		"paths": {
			"@fooBar/*": ["packages/*"]
		}
	}
}

I did pull out a few more things out of there that isn’t relevant to the issue.

---

my-test.spec.ts

import {calc} from `@fooBar/misc/calc`;

describe('Misc/Calc', () => {
	it('should do stuff', () => {
		expect(calc(1, 2)).toEqual(3);
	});
});

---

ERROR

Test suite failed to run

    Cannot find module '@fooBar/misc/calc' from 'my-test.spec.ts'
      
      at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:179:17)
      at Object.<anonymous> (packages/services/calculate/index.ts:43:121)

Which is odd, because I can tsc just fine and works 100% okay.

[keawade]

@geirsagberg, that fixes the problem for me.

@maraisr, adding this snippet to your package.json should allow you to take your custom name and map it to your actual folder:

"moduleNameMapper": {
  "^@fooBar/(.*)": "<rootDir>/src/barFoo/$1"
},

[benwinding]

To make it clear for others this solution worked:

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

module.exports = {
  preset: 'ts-jest',
  testEnvironment: 'node',
  moduleNameMapper: pathsToModuleNameMapper(compilerOptions.paths, {prefix: '<rootDir>/'})
};

And make sure the tsconfig.json file has no comments or extra commas.