如何在Jest Env中存根或忽略流星/会话？

Question

Jestjs gives me this error when I am testing a react component:

---

import {Session} from 'meteor/session' ". The error is "Cannot find module 'meteor/session' "

---

myTestFile

import PlanSetup from "../../../ui/pages/planSetup/planSetup";

let PlanSetupWrapper;
const PlansetupProps={
    name: "string",
    budget: "string",
    lang: { english: "en",
               French : "fr"
             }
};


describe('<PlanSetup />', () => {
    PlanSetupWrapper = mount(<PlanSetup {...PlansetupProps}/>);
    it('All child components renders correctly', () => {
 expect(PlanSetupWrapper).toMatchSnapshot();
});
});

Answer 1

**jest.config.js**
module.exports = {
    moduleNameMapper: {
      "^meteor/(.*)": "<rootDir>/imports/tests/mocks/meteor.js"
    },
    transform: {
        "^.+\\.(js|jsx)?$": "babel-jest",
        ".+\\.(css|styl|less|sass|scss)$": "/home/megha/Megha/TVStack/dan-tvstack-ui/node_modules/jest-css-modules-transform",
    },
    moduleFileExtensions: [
      'js',
      'jsx'

    ],
    modulePaths: [
        "<rootDir>/node_modules/"
      ],
    globals: {
              "window": true
            },

    unmockedModulePathPatterns: [
      '/^imports\\/.*\\.jsx?$/'
    ],
    setupFiles: [
              "<rootDir>/setupTests.js"
            ]
  };


**<rootDir>/imports/tests/mocks/meteor.js**

exports._session = {
    __: function(value) { return value }
  };

Answer 2

Welcome to Stack Overflow @MeghaRawat. There are a couple of things to consider here.

1) Keeping your components pure 2) Mocking up Meteor services

What this means is that any React components should be as pure as possible, and not reference Meteor - the containers should do that, and pass props to the components.

Jest doesn't know about Meteor, so any Meteor features will need to be stubbed, to prevent the the kind of problems you are encountering.

I may be able to find some code to help you if you need it.