The first module example is incorrect: // myModule.js export function myModule(someArg) { return someArg; } // main.js import myModu

The first module example is incorrect: // myModule.js export function myModule(someArg) { return someArg; } // main.js import myModule from 'myModule'; The import is importing a non-existent default export. Either the export needs to be changed to a default export: export default function myModule(someArg) { -or- the import needs to be changed to importing a member: import {myModule} from 'myModule';