Added Jest Environment on top of the test file

[arsho]

Without this comment I could not run the test. I was getting:

FAIL  src/sum.test.js
  ● Test suite failed to run

    TypeError: environment.setup is not a function
      
      at node_modules/jest-runner/build/run_test.js:112:23

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        0.395s
Ran all test suites.

Summary

Test plan

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[cpojer]

It seems like you are installing the wrong version of jest-environment-*. You need version 22 of all Jest dependencies, or version 21 of all Jest dependencies.

[arsho]

@cpojer ,
My package.json:

{
  "name": "jest-demo-test",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "react-scripts": "1.0.17"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "jest",
    "eject": "react-scripts eject"
  },
  "devDependencies": {
    "jest": "^22.0.4"
  }
}

It seems I have Jest version 22.
Can you elaborate your comment regarding this?

Thank you

[SimenB]

You cannot upgrade to jest 22 on your own when using CRA, see facebook/create-react-app#2639

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