Question 73840 in Reactjs Question posted in
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How would I mock out Meteor.settings with jest? – Reactjs

Meteor.settings is being used in a react class component that I am trying to mock. In the constructor of that component, Meteor.settings is accessed to get a url. I am using the moduleMapper from jest to mock Meteor.settings like so:

const Meteor = {
  settings: {
    public: {
      URL: "http://testing:0000",
    },
  },
};

export default Meteor;

In my test file I am importing my class component. After running jest, I am getting the following error:
TypeError: Cannot read property 'settings' of undefined.

To my understanding, the issue is that Meteor is not correctly being mocked.

How can I fix this issue, so that I can use a mock of Meteor.settings in my component?

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2

Answers


  1. Chosen as BEST ANSWER
    0

    Instead of mocking Meteor out in a separate file, I replaced each instance of Meteor with (((Meteor || {}).settings || {}).public || {})

    For your case just include an empty dictionary w/ each level of the meteor dictionary.


  2. 0

    I do this exact thing!

    1. Include meteor-jest-stubs per the instructions in the repo README.
    2. Stub out missing/custom pieces by including a file at __mocks__/meteor/meteor.js to mock the Meteor module.
    import { Meteor as MockedMongo } from "meteor/meteor"

export const Meteor = {
  ...MockedMongo,
  // then stub out any other meteor values, for example:
  absoluteUrl: jest.fn().mockReturnValue("http://localhost:3000/"),
  settings: {
    public: {
      URL: "http://testing:0000",
    },
    private: {
      MY_PRIVATE_KEY: "secret"
    }
  },
  subscribe: jest.fn().mockImplementation(() => ({
    ready: jest.fn().mockReturnValue(true),
    stop: jest.fn()
  })),
  // etc.
}

    Then jest picks up on the __mocks__ directory automatically and will mock out the Meteor value in your tests.
    https://jestjs.io/docs/manual-mocks#mocking-user-modules

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