Angular polyfill.ts 文件帮助。 polyfill 代码在哪里？以及处理它需要什么？

Question

所以我有一个 Angular 项目出错了，需要一些“polyfilling”。由于 Angular 不允许在不导出 webpack.config.js 文件的情况下对其进行编辑，我认为预期的意图是让开发人员编辑 polyfill.ts 文件。现在 src 文件夹中的 polyfill.ts 确实可以识别关键字“resolve”，因为它是以这种方式从 dns 导入的：

import {resolve} from 'dns';

这对于 Angular 来说很典型。但是来自 Angular 的错误消息表明，这个导入的解析应该有它没有的方法 .fallback。

这是 polyfill.ts 的代码图片：

这是前面提到的 Angular 错误的 sn-p：

有谁知道 Angular 期望这段代码放在哪里？除了我在这篇文章中的假设之外，polyfill.ts 文件是否还有其他用途？实际处理 polyfill 是否需要更健壮的代码？我假设它会全部放在这里，否则为什么将文件放在名为 polyfill 的 src 文件夹中，整个项目都可以看到它？如果这个问题看起来太宽泛，请道歉，因为我在黑暗中装模作样，任何和所有批评/建议都会受到赞赏。

以下是 Angular 生成的完整错误：

 $ ng serve
    Your global Angular CLI version (13.0.1) is greater than your local version (12.2.13). The local Angular CLI version is used.
    
    To disable this warning use "ng config -g cli.warnings.versionMismatch false".
    - Generating browser application bundles (phase: setup)...
    √ Browser application bundle generation complete.
    
    Initial Chunk Files   | Names         |      Size
    vendor.js             | vendor        |   6.48 MB
    polyfills.js          | polyfills     | 510.73 kB
    styles.css, styles.js | styles        | 383.69 kB
    main.js               | main          |  81.66 kB
    runtime.js            | runtime       |   6.69 kB
    
    | Initial Total |   7.44 MB
    
    Build at: 2021-11-26T16:15:03.838Z - Hash: b77d276f8b953e0e2990 - Time: 10837ms
    
    ./node_modules/sequelize/lib/dialects/abstract/connection-manager.js:82:15-63 - Warning: Critical dependency: the request of a dependency is an expression
    
    ./node_modules/sequelize/lib/dialects/abstract/connection-manager.js:89:13-32 - Warning: Critical dependency: the request of a dependency is an expression
    
    
    
    ./node_modules/sequelize/lib/dialects/mssql/query-generator.js:8:20-49 - Error: Module not found: Error: Can't resolve 'crypto' in 'C:\again\software-engineering-team-project-fourtothefloor\node_modules\sequelize\lib\dialects\mssql'
    
    BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
    This is no longer the case. Verify if you need this module and configure a polyfill for it.
    
    If you want to include a polyfill, you need to:
            - add a fallback 'resolve.fallback: { "crypto": require.resolve("crypto-browserify") }'
            - install 'crypto-browserify'
    If you don't want to include a polyfill, you can use an empty module like this:
            resolve.fallback: { "crypto": false }
    
    ./node_modules/sequelize/lib/dialects/postgres/hstore.js:3:15-35 - Error: Module not found: Error: Can't resolve 'pg-hstore' in 'C:\again\software-engineering-team-project-fourtothefloor\node_modules\sequelize\lib\dialects\postgres'
    
    ./node_modules/sequelize/lib/dialects/sqlite/connection-manager.js:5:11-24 - Error: Module not found: Error: Can't resolve 'fs' in 'C:\again\software-engineering-team-project-fourtothefloor\node_modules\sequelize\lib\dialects\sqlite'
    
    ./node_modules/sequelize/lib/model.js:5:15-32 - Error: Module not found: Error: Can't resolve 'assert' in 'C:\again\software-engineering-team-project-fourtothefloor\node_modules\sequelize\lib'
    
    BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
    This is no longer the case. Verify if you need this module and configure a polyfill for it.
    
    If you want to include a polyfill, you need to:
            - add a fallback 'resolve.fallback: { "assert": require.resolve("assert/") }'
            - install 'assert'
    If you don't want to include a polyfill, you can use an empty module like this:
            resolve.fallback: { "assert": false }
    
    
    
    ** Angular Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/ **
    
    
    × Failed to compile.

Answer 1

整理这篇文章：

webpack 5 angular polyfill for node.js crypto-js

对于这个错误，不需要 polyfill。只需编辑 angular.json 和 tsconfig.json 文件。

非 polyfilling 错误源于没有规范的服务器/客户端设置。