Jest: test Intl.DateTimeFormat

Question

I would like to test a filter function I wrote which return a date formatted using Intl.DateTimeFormat(\'en-GB\', options):

// module \"date.js\"
export default          


        

Answer 1

In package.json add the intl package

 "intl": "*",

In the jest.config.js

module.exports = {
    moduleNameMapper: {
        Intl: '/node_modules/intl/'
    }
};

Then in Date.spec.js

 describe(`Date by locale`, () => {
     beforeAll(() => {  global.Intl = require('intl'); });
    // Add your tests here. 
    // Add a temporary console.log to verify the correct output
 }