将 multer diskStorage 与 Typescript 结合使用

Question

我正在将 node.js 服务器转换为打字稿。

我的节点功能是：

const storage = multer.diskStorage({
    destination: function (req, file, cb) {
        const dir = './uploads/';
        mkdirp(dir, err => cb(err, dir));
    },
    filename: function (req, file, cb) {
        cb(null, file.originalname)
    }
});

const upload = multer({
    storage: storage
});

router.post('/test', upload.fields({name: 'image'}), async function (req, res, next) {
...
});

但我有很多错误。例如，我无法将文件参数设置为 Express.File 类型，“memoryStorage”不接受参数或 mkdirp 告诉我它不可调用。

Answer 1

以下是我使用@types/multer.

如果您还没有安装 multer 包的类型定义，请首先安装：

npm i --save-dev @types/multer

导入和type别名

import { Request } from 'express'
import multer, { FileFilterCallback } from 'multer'

type DestinationCallback = (error: Error | null, destination: string) => void
type FileNameCallback = (error: Error | null, filename: string) => void

为了storage

export const fileStorage = multer.diskStorage({
    destination: (
        request: Request,
        file: Express.Multer.File,
        callback: DestinationCallback
    ): void => {
        // ...Do your stuff here.
    },

    filename: (
        req: Request, 
        file: Express.Multer.File, 
        callback: FileNameCallback
    ): void => {
        // ...Do your stuff here.
    }
})

为了fileFilter

export const fileFilter = (
    request: Request,
    file: Express.Multer.File,
    callback: FileFilterCallback
): void => {
    if (
        file.mimetype === 'image/png' ||
        file.mimetype === 'image/jpg' ||
        file.mimetype === 'image/jpeg'
    ) {
        callback(null, true)
    } else {
        callback(null, false)
    }
}

为了使代码更清晰并分离关注点，请将上述两个常量放在单独的文件中，例如config/multer.ts或util/multer.ts

用法

app.ts在or中导入并使用上述常量server.ts：

app.use(multer({ storage: fileStorage, fileFilter: fileFilter })

Answer 2

我使用了以下代码并且它有效

   const guidGenerator = require('uuid/v1');

   // configurates how the files are gonna be stored
   const storage = multer.diskStorage({
       destination: function (req: Express.Request, file: Express.Multer.File, callback: (error: Error | null, destination: string) => void) {
        callback(null, './upload/');
    },
    filename: function (req: Request, file: Express.Multer.File, callback: (error: Error | null, filename: string) => void) {
        const guid = guidGenerator();
        callback(null, guid + '_' + file.originalname);
    }
});