Error when using jest + collectCoverage/babel-plugin-lodash

I posted this issue before on https://github.com/facebook/jest/issues/3959 and https://github.com/lodash/babel-plugin-lodash/issues/179

Using babel-plugin-lodash, collectCoverage enabled and a lodash function as show below imported from test file, results into an error.

import { flow, flatten } from 'lodash/fp'

export const testFunction1 = flatten 
// export const testFunction2 = flow(flatten) 

example#testFunction1 npm test will output

    /home/nam/projects/jest-babel-lodash-issue/src/example.js:3
    var testFunction1 = /* istanbul ignore next */exports.testFunction1 = ();
                                                                           ^
    
    SyntaxError: Unexpected token )

example#testFunction2 npm test will output

    ReferenceError: /home/nam/projects/jest-babel-lodash-issue/src/example.js: Container is falsy
      
      at NodePath._replaceWith (node_modules/babel-traverse/lib/path/replacement.js:170:11)

Removing collectCoverage from package.json lets the tests run without failure. Removing babel-plugin-lodash from .babelrc or importing directly from lodash also runs without failure.

Testcase https://github.com/namjul/jest-babel-lodash-issue

[patsissons]

Ran into this too with babel-plugin-dotenv-import (which is very similar to react-native-dotenv). The solution is to import all dotenv defines in a single file and then ignore that file for coverage:

    "coveragePathIgnorePatterns": [
      "<rootDir>/node_modules/",
      "<rootDir>/src/utils/env.js"
    ],

[AndersDJohnson]

Have you tried moving thebabel-plugin-lodash plugin to a non-test environment config?

{
  "plugins": [],
  "env": {
    "production": {
      "plugins": ["lodash"]
     }
  }
}

then when running tests, use:

BABEL_ENV=test jest --coverage

https://github.com/namjul/jest-babel-lodash-issue/issues/1 https://github.com/facebook/jest/issues/3959#issuecomment-317018979