javascript - 要求未在反射元数据上定义 - __webpack_require__ 问题

Question

我正在尝试在 Visual Studio 上启动我的 Angular 应用程序，但是当它启动时，它停留在“正在加载...”部分。

如果我阅读 Chrome 的错误控制台，我会收到以下错误:

Uncaught ReferenceError: require is not defined at Object. < anonymous > __ webpack_require __

reflect-metadata 包含以下内容: module.exports = require("reflect-metadata"); ，其中“require”导致错误。

<小时/>

这是我的一些代码...

webpack.config.js

const path = require('path');    
const webpack = require('webpack');
const merge = require('webpack-merge');
const AotPlugin = require('@ngtools/webpack').AotPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
var nodeExternals = require('webpack-node-externals');

module.exports = (env) => {
    // Configuration in common to both client-side and server-side bundles
    const isDevBuild = !(env && env.prod);
    const sharedConfig = {

        externals: [nodeExternals()], // in order to ignore all modules in node_modules folder

        stats: { modules: false },
        context: __dirname,
        resolve: { extensions: [ '.js', '.ts' ] },
        output: {
            filename: '[name].js',
            publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
        },
        module: {
            rules: [
                { test: /\.ts$/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader', 'angular2-router-loader'] : '@ngtools/webpack' },
                { test: /\.html$/, use: 'html-loader?minimize=false' },
                { test: /\.css$/, use: [ 'to-string-loader', 'style-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
                { test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
            ]
        },
        plugins: [new CheckerPlugin()]
    };

    // Configuration for client-side bundle suitable for running in browsers
    const clientBundleOutputDir = './wwwroot/dist';
    const clientBundleConfig = merge(sharedConfig, {
        entry: { 'main-client': './ClientApp/boot.browser.ts' },
        output: { path: path.join(__dirname, clientBundleOutputDir) },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./wwwroot/dist/vendor-manifest.json')
            })
        ].concat(isDevBuild ? [
            // Plugins that apply in development builds only
            new webpack.SourceMapDevToolPlugin({
                filename: '[file].map', // Remove this line if you prefer inline source maps
                moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
            })
        ] : [
            // Plugins that apply in production builds only
            new webpack.optimize.UglifyJsPlugin(),
            new AotPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.browser.module#AppModule'),
                exclude: ['./**/*.server.ts']
            })
        ])
    });

    // Configuration for server-side (prerendering) bundle suitable for running in Node
    const serverBundleConfig = merge(sharedConfig, {
        resolve: { mainFields: ['main'] },
        entry: { 'main-server': './ClientApp/boot.server.ts' },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./ClientApp/dist/vendor-manifest.json'),
                sourceType: 'commonjs2',
                name: './vendor'
            })
        ].concat(isDevBuild ? [] : [
            // Plugins that apply in production builds only
            new AotPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.server.module#AppModule'),
                exclude: ['./**/*.browser.ts']
            })
        ]),
        output: {
            libraryTarget: 'commonjs',
            path: path.join(__dirname, './ClientApp/dist')
        },

        target: 'node',
        devtool: 'inline-source-map'
    });

    return [clientBundleConfig, serverBundleConfig];
};

<小时/>

在互联网上搜索，所有故障排除都建议在 systemjs.config 文件上执行某些操作，但我的不是 angular-cli 应用程序，所以我无法执行此操作。

<小时/>

更新部分

1. 更新#1

看起来问题是由在浏览器模式下执行的 webpack-node-externals 引起的。

必须找到另一种方法。

<小时/>

有任何疑难解答或潜在的解决方案建议吗？

提前致谢!

<小时/>

更新#2

我已经成功了，请参阅下面的答案

Answer 1

明白了!

该问题是由我的常用配置中使用的 webpack-node-externals 引起的。

查看我的问题和我对自己问题的回答:Webpack - Excluding node_modules with also keep a separated browser and server management了解更多详情。

所以，简而言之，我遵循的步骤如下:

• 安装 requireJS ==> http://requirejs.org/docs/node.html
• 从我的通用 webpack 配置中删除 externals: [nodeExternals()],//为了忽略 node_modules 文件夹中的所有模块并将其添加到我的服务器配置(在我的问题之前完成，但这是非常重要的一步)[请参阅此答案或下面的代码片段中链接的问题中的 webpack.config.js 内容]
• 添加 target: 'node', 在我上面的外部点之前，在我的服务器端部分下(在我的问题之前完成，但这是一个非常重要的步骤)[参见问题中的 webpack.config.js 内容链接在这个答案或下面的代码片段中]
  这确保浏览器端保留 target:'web' (默认目标)，并且 target 成为仅用于服务器的节点。
• 从 powershell 手动启动 webpack 配置 vendor 命令 webpack --config webpack.config.vendor.js
• 从 powershell 手动启动 webpack 配置命令 webpack --config webpack.config.js

这对我有用!希望它也适用于阅读此问题并遇到此问题的其他人!

<小时/>

webpack.config.js内容:

const path = require('path');    
const webpack = require('webpack');
const merge = require('webpack-merge');
const AotPlugin = require('@ngtools/webpack').AotPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;

var nodeExternals = require('webpack-node-externals');

module.exports = (env) => {
    // Configuration in common to both client-side and server-side bundles
    const isDevBuild = !(env && env.prod);
    const sharedConfig = {
        //removed from here, moved below.
        //externals: [nodeExternals()], // in order to ignore all modules in node_modules folder

        stats: { modules: false },
        context: __dirname,
        resolve: { extensions: [ '.js', '.ts' ] },
        output: {
            filename: '[name].js',
            publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
        },
        module: {
            rules: [
                { test: /\.ts$/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader', 'angular2-router-loader'] : '@ngtools/webpack' },
                { test: /\.html$/, use: 'html-loader?minimize=false' },
                { test: /\.css$/, use: [ 'to-string-loader', 'style-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
                { test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
            ]
        },
        plugins: [new CheckerPlugin()]
    };

    // Configuration for client-side bundle suitable for running in browsers
    const clientBundleOutputDir = './wwwroot/dist';
    const clientBundleConfig = merge(sharedConfig, {
        entry: { 'main-client': './ClientApp/boot.browser.ts' },
        output: { path: path.join(__dirname, clientBundleOutputDir) },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./wwwroot/dist/vendor-manifest.json')
            })
        ].concat(isDevBuild ? [
            // Plugins that apply in development builds only
            new webpack.SourceMapDevToolPlugin({
                filename: '[file].map', // Remove this line if you prefer inline source maps
                moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
            })
        ] : [
            // Plugins that apply in production builds only
            new webpack.optimize.UglifyJsPlugin(),
            new AotPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.browser.module#AppModule'),
                exclude: ['./**/*.server.ts']
            })
        ])
    });

    // Configuration for server-side (prerendering) bundle suitable for running in Node
    const serverBundleConfig = merge(sharedConfig, {
        resolve: { mainFields: ['main'] },
        entry: { 'main-server': './ClientApp/boot.server.ts' },
        plugins: [
            new webpack.DllReferencePlugin({
                context: __dirname,
                manifest: require('./ClientApp/dist/vendor-manifest.json'),
                sourceType: 'commonjs2',
                name: './vendor'
            })
        ].concat(isDevBuild ? [] : [
            // Plugins that apply in production builds only
            new AotPlugin({
                tsConfigPath: './tsconfig.json',
                entryModule: path.join(__dirname, 'ClientApp/app/app.server.module#AppModule'),
                exclude: ['./**/*.browser.ts']
            })
        ]),
        output: {
            libraryTarget: 'commonjs',
            path: path.join(__dirname, './ClientApp/dist')
        },

        //added target and externals HERE, in order to prevent webpack to read node_modules
        //this also prevents fake-positives parsing errors
        target: 'node',
        externals: [nodeExternals()], // in order to ignore all modules in node_modules folder,
            devtool: 'inline-source-map'
        });

    return [clientBundleConfig, serverBundleConfig];
};