Meteor react jest testing

Question

Simple jest test just to check if the react component can render and it fails because I import

import { Meteor } from 'meteor/meteor'

the full error is...

 PASS  imports/__partials/Navigation/__tests__/Navigation.jest.js
 PASS  imports/__layouts/AuthLayout/__tests__/AuthLayout.jest.js
 FAIL  imports/features/oAuth/ui/LoginLayout/__tests__/LoginLayout.jest.js
  ● Test suite failed to run

    Cannot find module 'meteor/meteor' from 'index.js'

      at Resolver.resolveModule (node_modules/jest-resolve/build/index.js:142:17)
      at Object.<anonymous> (imports/features/oAuth/ui/LoginLayout/index.js:2:41)
      at Object.<anonymous> (imports/features/oAuth/ui/LoginLayout/__tests__/LoginLayout.jest.js:4:40)

 PASS  imports/staticTests/quickCheckboxTest/__tests__/CheckboxWithLabel.jest.js
 PASS  imports/staticTests/quickLinkTest/__tests__/Link.react.jest.js

I'm going to assume its because meteor doesn't build and therefore meteor/meteor doesn't exist, any help in getting this to work will be appreciated. :)

Edit...

I was right in my assumption, it's basically because meteor hasn't built the npm modules.

Answer 1

You can easily stub Meteor modules using the "moduleNameMapper" in your jest config file:

"moduleNameMapper": {
  "^meteor/(.*)": "<rootDir>/meteorMocks.js"
}

And in meteorMocks.js:

export const Meteor = {
  call: () => null,
  // ... more stuff you'd like to mock on the Meteor object
};

Then you can do

import { Meteor } from 'meteor/meteor';

in your test files.

Just do the same with all modules you need to mock (like Tracker or ReactiveVar).