为什么 webpack 认为我的模块不是模块？

Question

I'm trying to import react in the typical way:

import React from 'react'

but I'm getting this error:

Uncaught SyntaxError: Cannot use import statement outside a module

What could cause webpack to not treat my file properly as a module?

Answer 1

One likely cause is that the HTML is trying to point to the raw, uncompiled source script, rather than the script which is run through babel and compiled by webpack.

The location of the uncompiled source script is whatever the path to that file is in the repository.

The location of the compiled output script is whatever the webpack.config.js output filename is set to, with the path being the dev server path or if a production build, whatever the output path is set to.