node_modules/react-native-aws3-cognito ReferenceError: FormData is not defined

[bryanboyko]

🐛 Bug Report

 FAIL  ./App.test.js
  ● Test suite failed to run

    ReferenceError: FormData is not defined

      at Object.<anonymous> (node_modules/react-native-aws3-cognito/lib/Request.js:148:20)
      at Object.<anonymous> (node_modules/react-native-aws3-cognito/lib/RNS3.js:16:16)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        2.619s
Ran all test suites.
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! @ test: `jest`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the @ test script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

To Reproduce

Follow setup instructions here

https://docs.expo.io/versions/latest/guides/testing-with-jest/

Install react-native-aws3-cognito in your project

Execute npm run test

Attempt to include react-native-aws3-cognito in package.json transformIgnorePatterns like so

  "jest": {
    "preset": "jest-expo",
    "transformIgnorePatterns": [
      "node_modules/(?!(jest-)?react-native|react-clone-referenced-element|@react-native-community|expo(nent)?|@expo(nent)?/.*|react-navigation|@react-navigation/.*|@unimodules/.*|unimodules|@sentry/.*|sentry-expo|native-base|react-native-aws3-cognito/.*)"
    ]
  },

Note that error still occurs

Expected behavior

Tests would run without error

envinfo

  System:
    OS: macOS Mojave 10.14.4
    CPU: (8) x64 Intel(R) Core(TM) i7-4870HQ CPU @ 2.50GHz
  Binaries:
    Node: 12.12.0 - /usr/local/bin/node
    Yarn: 1.19.1 - /usr/local/bin/yarn
    npm: 6.11.3 - /usr/local/bin/npm

[thymikee]

That's likely not an issue with transformation. The error is ReferenceError: FormData is not defined which means there's no FormData available for some reason. You'll need to dig in into node_modules to see why.

Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions. You'll find more on Jest docs help page. Thank you :)

[SimenB]

FormData is not a global in Node, so if your testEnvironment is node (or a derivation of it) it won't be available. You can probably polyfill it in a setupFile though.

[bryanboyko]

Thanks guys!

Was able to resolve by adding a setupTests.js file that looks like

function FormDataMock() {
    this.append = jest.fn();
}
global.FormData = FormDataMock

And then configuring jest to use the setupTests.js file by adding setupFilesAfterEnv to my package.json

  "jest": {
    "preset": "jest-expo",
    ...
    "setupFilesAfterEnv": [
      "<rootDir>/setupTests.js"
    ]
  }

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.
Please note this issue tracker is not a help forum. We recommend using StackOverflow or our discord channel for questions.