NestJS Jest cannot find module with absolute path

Question

I have a quite new NestJS application. I'm trying to run unit tests, but they keep failing due to 'cannot find module..' when using absolute paths ("src/users/..."), but works when using relative paths ("./users/.."). Is there anything wrong with my configuration here?

Jest setup in package.json:

"jest": {
  "moduleFileExtensions": [
    "js",
    "json",
    "ts"
  ],
  "rootDir": "src",
  "testRegex": ".spec.ts$",
  "transform": {
    "^.+\\.(t|j)s$": "ts-jest"
  },
  "coverageDirectory": "../coverage",
  "testEnvironment": "node"
}

tsconfig.json:

{
  "compilerOptions": {
    "module": "commonjs",
    "declaration": true,
    "removeComments": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "allowSyntheticDefaultImports": true,
    "target": "es2017",
    "sourceMap": true,
    "outDir": "./dist",
    "baseUrl": "./",
    "incremental": true
  }
}

Answer 1

I had the same issue, the problem was the default jest configuration created by Nestjs.

I changed "rootDir": "src" to "rootDir": "./" and add "modulePaths": ['<rootDir>'].

Finaly, my jest configuration looks like this:

  moduleFileExtensions: ['js', 'json', 'ts'],
  rootDir: './',
  modulePaths: ['<rootDir>'],
  testRegex: 'spec.ts$',
  transform: {
    '^.+\\.(t|j)s$': 'ts-jest'
  },
  coverageDirectory: './coverage',
  testEnvironment: 'node',

If you have some relative paths to your config you will probably have to update them because your rootDir is not src anymore.

You can even remove rootDir is you setup the jest config in package.json or if the config file is located at the root of your project, as explained in the doc: https://jestjs.io/docs/en/configuration#rootdir-string

And if you want read about modulePaths: https://jestjs.io/docs/en/configuration#modulepaths-arraystring

Hope it will also work for you.

Answer 2

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I spent a lot of time searching and figuring this problem out.

---

My Specific Issue 👇

I faced this issue when running e2e tests with NestJS. I set up the absolute path from the root of the project. Here is my tsconfig.json.

{
  "compilerOptions": {
    "module": "commonjs",
    "declaration": true,
    "removeComments": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "allowSyntheticDefaultImports": true,
    "target": "es2017",
    "sourceMap": true,
    "outDir": "./dist",
    "baseUrl": "./",
    "paths": {
      "src/*": ["./src/*"]
    },
    "incremental": true,
    "skipLibCheck": true,
    "strictNullChecks": false,
    "noImplicitAny": false,
    "strictBindCallApply": false,
    "forceConsistentCasingInFileNames": false,
    "noFallthroughCasesInSwitch": false
  }
}

---

Here is what solved my problem.

add moduleDirectories: ['<rootDir>/../', 'node_modules'] to test/jest-e2e.config.js.

working test/jest-e2e.config.js 👇

{
  moduleFileExtensions: ['js', 'json', 'ts'],
  rootDir: '.',
  testEnvironment: 'node',
  testRegex: '.e2e-spec.ts$',
  transform: {
    '^.+\\.(t|j)s$': 'ts-jest',
  },
  moduleDirectories: ['<rootDir>/../', 'node_modules'],
};

NOTE: moduleDirectories options should be paths relative to the jest confi g file, it is necessary to start you path from <rootDir> and go back as needed. For details of this visit https://github.com/nestjs/nest/issues/5522#issuecomment-714592183

---

Here is the link to my repo if you want to have a look at it. https://github.com/mabdullahadeel/nest-bookmarker

---

Answer 3

You need to configure how jest resolves module paths by configuring the moduleNameMapper.

package.json

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