Jest encountered an unexpected token when importing lodash functions in Typescript

Question

I am getting an error: Jest encountered an unexpected token when trying to compile in my test classes on lines:

import isEqual from 'lodash-es/isEqual';
import isEmpty from 'lodash-es/isEmpty';

In my package.json I setup my dependency like this:

  "dependencies": {
    "lodash-es": "^4.17.11"
  },
  "devDependencies": {
     ...
     "@types/jest": "^23.3.13",
     "@types/node": "^11.13.4",
     "@types/lodash-es": "^4.17.3",
     "jest": "^25.2.4",
     "ts-jest": "^23.10.4",
     "tslint": "^5.14.0",
     "typescript": "^3.6.4"
     ...
  }

I set my jest config like this:

module.exports = {
    clearMocks: true,
    collectCoverageFrom: ['<rootDir>/src/**/*.+(ts)'],
    coverageDirectory: 'coverage',
    coveragePathIgnorePatterns: [
        '/test/',
        '/dist/',
        '<rootDir>/src/index.ts',
        '<rootDir>/src/imports.ts'
    ],
    coverageThreshold: {
        global: {
            branches: 100,
            functions: 100,
            lines: 100,
            statements: 100,
        },
    },
    moduleFileExtensions: ['ts', 'js', 'json', 'node'],
    preset: "ts-jest/presets/js-with-ts",
    rootDir: '.',
    testEnvironment: 'node',
    testMatch: ['<rootDir>/test/**/*.test.(js|ts)'],
    transform: {
        '\\.(js|ts)$': '<rootDir>/node_modules/babel-jest'
    },
    transformIgnorePatterns: [
        "node_modules/(?!(lodash-es)/)"
    ]
  };

As suggested by other posts I've tried adding in transform, and transformIgnorePatterns. I've also tried with jest --no-cache, and removing node_modules, package-lock.json, and then rebuilding with tsc, and using NodeJS 12. Yet, I still get the same error. Is there something I am misconfiguring?

Answer 1

My jest configuration had a couple mistakes:

    transform: {
            '\\.(js|ts)$': 'ts-jest',
    },

I also needed to update the preset to: preset: 'ts-jest', . I was mixing and matching configuration from different sources which was causing weird compile errors. Updating the configuration fixed my issue.