node.js - 无法在 TypeScript 中扩展 Express Request

Question

这个问题已经被问过好几次了，但是没有一个答案对我有用。我正在尝试扩展 Express Request 对象以包含一个属性来存储 User 对象。我创建了一个声明文件 express.d.ts，并将其放在与我的 tsconfig.json 相同的目录中:

import { User } from "./src/models/user";

declare namespace Express {
    export interface Request {
        user: User;
    }
}

然后我尝试在 secured-api.ts 中对其进行赋值:

import express from 'express';
import { userService } from '../services/user';

router.use(async (req, res, next) => {
    try {
        const user = await userService.findByUsername(payload.username);

        // do stuff to user...

        req.user = user;
        next();
    } catch(err) {
        // handle error
    }
});

我收到以下错误:

src/routes/secured-api.ts:38:21 - error TS2339: Property 'user' does not exist on type 'Request'.

38                 req.user = user;
                       ~~~~

我的 User 类是:

import { Model, RelationMappings } from 'objection';

export class User extends Model {

    public static tableName = 'User';
    public static idColumn = 'username';

    public static jsonSchema = {
        type: 'object',
        required: ['fname', 'lname', 'username', 'email', 'password'],

        properties: {
            fname: { type: 'string', minLength: 1, maxLength: 30 },
            lname: { type: 'string', minLength: 1, maxLength: 30 },
            username: { type: 'string', minLength: 1, maxLength: 20 },
            email: { type: 'string', minLength: 1, maxLength: 320 },
            password: { type: 'string', minLength: 1, maxLength: 128 },
        }
    };

    public static modelPaths = [__dirname];

    public static relationMappings: RelationMappings = {

    };

    public fname!: string;
    public lname!: string;
    public username!: string;
    public email!: string;
    public password!: string;
}

我的 tsconfig.json 是:

{
    "compilerOptions": {
      "target": "es6",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
      "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
      "lib": ["es2015"],                             /* Specify library files to be included in the compilation. */
      "outDir": "./build",                      /* Redirect output structure to the directory. */
      "strict": true,                           /* Enable all strict type-checking options. */
      "esModuleInterop": true                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
    }
}

我的目录结构是:

backend/
    package.json
    tsconfig.json
    express.d.ts
    src/
        models/
            user.ts
        routes/
            secured-api.ts

我在这里做错了什么？

Answer 1

问题是您没有扩充由 express 定义的 Express 全局命名空间您正在模块中创建一个新的命名空间(一旦您使用该文件就成为一个模块导入)。

解决方法是在global中声明命名空间

import { User } from "./src/models/user";

declare global {
    namespace Express {
        export interface Request {
            user: User;
        }
    }
}

或者不使用模块导入语法，只引用类型:

declare namespace Express {
    export interface Request {
        user: import("./src/models/user").User;
    }
}