Webpack捆绑包未导出，无法导入

Question

I created my react Project A using Create-React-app . Then I bundle it them with Webpack and saved in my Git account. Now I create another project(Called it Project B )in different directory. Download Project A directly from git. And trying to use it like so:

import React from 'react';
import ReactDOM from 'react-dom';
import { Main } from 'project-A/dist/main'

ReactDOM.render(<Main />, document.getElementById('root'));

I am getting an error like following:

Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: undefined. You likely forgot to export your component from the file it's defined in, or you might have mixed up default and named imports.

The webpack from Project A looks like this:

const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const HtmlWebPackPlugin = require("html-webpack-plugin");
const nodeExternals = require("webpack-node-externals");

module.exports = [
    {
        /*Client Side*/
        module: {
            rules: [
                {
                    test: /\.(js|jsx)$/,
                    exclude: /node_modules/,
                    use: {
                        loader: "babel-loader"
                    }
                },
                {
                    test: /\.html$/,
                    use: {
                        loader: "html-loader",
                        options: { minimize: true }
                    }
                },
                {
                    test: /\.css$/,
                    use: [MiniCssExtractPlugin.loader,"css-loader"]
                }
            ]
        },
        plugins: [
            new HtmlWebPackPlugin({
                template: "./public/index.html",
                filename:"./index.html"
            }),
            new MiniCssExtractPlugin({
                filename: "[name].css",
                chunkFilename:"[id].css"
            })
        ]
    }
]

I have research through the github and tried to change the name import, it still does not work.

Project A's component looks like this:

App.js:

  render() {
    return (
      <div>
        {this.renderCodeAuthCard()}
        {this.renderConfirmCard()}
        {this.renderVerifyCard()}
      </div>
    );
  }

export default App;

index.js:

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';

ReactDOM.render(<App />, document.getElementById('root'));

Apparently webpack is not exporting the bundle file that is created in Project A. Since the import yields " undefine ".

I am trying to find a way to export my webpack bundle file and use it in another project.

Any help will be appreciated

Answer 1

Its because you are not exporting any thing from index.js of Project A . The libraries installed by npm export functions from index.js .