moduleNameMapper doesn't work for me

I change the path configuration in my tsconfig, for better paths. But now i cannot execute my testcases. So i checked the following documentaries:

• jest

• ts-jest

Is that an error or a misconfiguration? By Error i will do a small repo.

Snippet tsconfig.json

...
        "rootDirs": [
          "src/",
          "test/"
        ],
        "baseUrl": ".",
        "paths": {
          "log": ["src/util/log"],
          "server": ["src/server"],
          "util/*": ["src/util/*"],
          "api/*": ["src/api/*"],
          "middleware/*": ["src/middleware/*"],
          "service/*": ["src/service/*"],
          "types/*": ["src/types/*"],
          "test/*": ["test/*"],
          "mocks/*": ["test/mocks/*"],
          "src/*": ["src/*"]
        },

Snippet package.json

...
    "globals": {
      "ts-jest": {
        "tsConfigFile": "tsconfig.json"
      }
...
    "moduleDirectories": [
      ".",
      "node_modules"
    ],
    "moduleNameMapper": {
      "log": "<rootDir>/src/util/log",
      "server": "<rootDir>/src/server",
      "util/(.*)": "<rootDir>/src/util/$1",
      "api/(.*)": "<rootDir>/src/api/$1",
      "middleware/(.*)": "<rootDir>/src/middleware/$1",
      "service/(.*)": "<rootDir>/src/service/$1",
      "types/(.*)": "<rootDir>/src/types/$1",
      "test/(.*)": "<rootDir>/test/$1",
      "mocks/(.*)": "<rootDir>/test/mocks/$1",
      "src/(.*)": "<rootDir>/src/$1"
    }
...

ERROR

● Test suite failed to run

   Configuration error:

   Could not locate module ../util/params (mapped as C:\Users\XXX\backend\src\util\params)

   Please check:

   "moduleNameMapper": {
     "/util\/(.*)/": "C:\Users\XXX\backend\src\util\$1"
   },
   "resolver": undefined

[DarkLite1]

I almost gave up on this but finally fixed it.

// tsconfig.json
{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "@environment": ["src/environment"],
      "@test-utils/*": ["src/test-utils/*"]
    },
}

The key below was that moduleDirectories was not required to get it to work but modulePaths is. Also a piece of advice is to use <rootDir> instead of ./.

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

module.exports = {
  roots: ['<rootDir>'],
  modulePaths: ['<rootDir>'],
  moduleNameMapper: pathsToModuleNameMapper(compilerOptions.paths),
}

[kulshekhar]

Changing the moduleDirectories key in the jest configuration got this working (I tested with jest --no-cache from the root directory)

    "moduleDirectories": [
      ".",
      "src",
      "src/util",
      "node_modules"
    ]

Hope this helps