NodeJS - Running tests with Jest: getting an error with TypeScript config file

Question

I'm trying to run some tests with Jest but I keep getting an error. It's something to do with a TypeScript config file, I already searched but didn't find much. I'm using NodeJS, TypeORM with TypeScript.

I'm getting this error when running yarn test:

Error: Jest: Failed to parse the TypeScript config file

C:\Users\demis\Documents\Projects\Personal\nlw_node\jest.config.ts TypeError: registerer.enabled is not a function*** at readConfigFileAndSetRootDir (C:\Users\demis\Documents\Projects\Personal\nlw_node\node_modules\jest-config\build\readConfigFileAndSetRootDir.js:150:13) at readConfig (C:\Users\demis\Documents\Projects\Personal\nlw_node\node_modules\jest-config\build\index.js:217:18) at readConfigs (C:\Users\demis\Documents\Projects\Personal\nlw_node\node_modules\jest-config\build\index.js:406:26) at runCLI (C:\Users\demis\Documents\Projects\Personal\nlw_node\node_modules@jest\core\build\cli\index.js:230:59) at Object.run (C:\Users\demis\Documents\Projects\Personal\nlw_node\node_modules\jest-cli\build\cli\index.js:163:37)

First.test.ts:

describe("First", () => {
  it("should", () => {
    expect(2 + 2).toBe(4);
  });
});

jest.config.ts:

export default {
  bail: true,
  clearMocks: true,
  coverageProvider: "v8",
  preset: "ts-jest",
  testEnvironment: "node",
  testMatch: ["**/tests/*.test.ts"]
};

tsconfig.json:

{
   "compilerOptions": {
      "lib": [
         "es5",
         "es6"
      ],
      "target": "es5",
      "module": "commonjs",
      "moduleResolution": "node",
      "outDir": "./build",
      "emitDecoratorMetadata": true,
      "experimentalDecorators": true,
      "sourceMap": true
   }
}

package.json:

{
  "name": "nlw_node",
  "version": "0.0.1",
  "description": "Awesome project developed with TypeORM.",
  "devDependencies": {
    "@types/express": "^4.17.11",
    "@types/jest": "^26.0.20",
    "@types/node": "^8.0.29",
    "@types/uuid": "^8.3.0",
    "jest": "^26.6.3",
    "nodemon": "^2.0.7",
    "ts-jest": "^26.5.3",
    "ts-node": "3.3.0",
    "typescript": "^4.2.3"
  },
  "dependencies": {
    "body-parser": "^1.18.1",
    "express": "^4.15.4",
    "mysql": "^2.14.1",
    "reflect-metadata": "^0.1.10",
    "typeorm": "0.2.31",
    "uuid": "^8.3.2"
  },
  "scripts": {
    "start": "nodemon src/index.ts",
    "typeorm": "ts-node node_modules/typeorm/cli.js",
    "test": "jest"
  }
}

ormconfig.ts:

{
  "type": "mysql",
  "host": "localhost",
  "port": 3306,
  "username": "root",
  "password": "root",
  "database": "nlw_node",
  "synchronize": true,
  "logging": false,
  "entities": ["src/api/models/**.ts"],
  "migrations": ["src/database/migrations/**.ts"],
 
  "cli": {
    "entitiesDir": "src/entity",
    "migrationsDir": "./src/database/migrations",
    "subscribersDir": "src/subscriber"
  }
}

Answer 1

Wanting to leave this here just in case it helps someone.

TLDR; run your IDE's "format this file" functionality on your tsconfig.json.

This is the error I was getting:

SyntaxError: /Users/foo/bar/baz/project/tsconfig.json: Expected double-quoted property name in JSON at position 495 (line 20 column 5)

I couldn't find the offending (assumed) single quote, or, well, anything wrong with it all. I wasted so much time on this lol..

The fix was to literally just right click inside my tsconfig.json file and format it (I'm using VSCode FYI).

Answer 2

I had the silliest of issues. There was a comma at the end of my tsconfig file like the following:-

{
  ...
  "ts-node": {
    "compilerOptions": {
      "jsx": "react-jsx",
      "module": "commonjs",
      "jsxImportSource": "",
      "paths": {
        "~/*": [
          "./src/*"
        ]
      }
    },
    "require": [
      "tsconfig-paths/register"
    ],
    "transpileOnly": true
  }, // <----- This was the offending comma
}

Removing this comma fixed the issue for me.

Answer 3

Remove the ts-node package and install ts-node-dev instead.

Answer 4

Installing ts-jest should solve this problem if you have ts-node installed.

Answer 5

I had the same problem, but the tests were running once.

It turned out I needed to delete node_modules and yarn.lock and reinstall everything again.

Answer 6

I had exactly the same error this am, trying to run tests in jest with Angular and Typescript.

My problem was solved by re-installing jest:

npm install --save-dev jest

This then showed an underlying configuration issue with my set up - but at least I don't see the failed error.

Answer 7

I added exclude and include on my tsconfig.json file and it worked.

{
  "compilerOptions": {
    "target": "esnext",
    "module": "commonjs",
    "rootDir": "./",
    "baseUrl": "./src",
    "outDir": "./dist",
    "allowJs": true,
    "noEmit": false,
    "noEmitOnError": true,
    "noUnusedLocals": true,
    "strict": true,
    "moduleResolution": "node",
    "sourceMap": true,
    "resolveJsonModule": true,
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "forceConsistentCasingInFileNames": true,
    "removeComments": true,
    "skipLibCheck": true,
    "typeRoots": [
      "@types",
      "./node_modules/@types"
    ]
  },
  "exclude": [
    "node_modules",
    "dist"
  ],
  "include": [
    "src/**/*",
    "src/__tests__",
    "jest.config.js"
  ]
}

Answer 8

Check if the babel.config.js file is in the root / folder of the project, if is not the problem follow these instructions