processImageMiddleware.ts

import multer from "multer";

/**
 * For local directory
 */
const storage = multer.diskStorage({
    destination: (req, file, cb) => {
        cb(null, 'uploads');
    },
    filename: (req, file, cb) => {
        cb(null, file.originalname);
    }
});

const imageFilter = (req: any, file: any, cb: any) => {
    if (!file.originalname.match(/\.(JPG|jpg|jpeg|png|gif)$/)) {
        return cb(new Error('Only image files are allowed!'), false);
    }
    cb(undefined, true)
};

const processImageMiddleware = multer({
    fileFilter: imageFilter,
    storage: multer.memoryStorage(), //storage
    limits: {
        fileSize: 5 * 1024 * 1024, // keep images size < 5 MB
    },
}).single('file');

export default processImageMiddleware;

route.ts

import { Request, Response } from "express";
import { checkPostRequestBody } from "../../middleware/checks";
import { BlogController } from "./blogController";
import FirebaseImageProvider, { IFileStatus } from "./providers/firebaseImageProvider";
import UploadImageProvider from "./providers/imageProvider";
import processImageMiddleware from "./providers/processImageMiddleware";

export default [
    {
        path: "/api/v1/uploadImages",
        method: "post",
        handler: [
            checkPostRequestBody,
            async (req: Request, res: Response, next: any) => {
                processImageMiddleware(req, res, async (err) => {
                    if (!req.file) {
                        res.status(400).send('Please attach the file');
                        return;
                    }

                    const file = req.file;
                    const firebaseImageProvider = new FirebaseImageProvider(req, res);
                    firebaseImageProvider.uploadImageToFirebase(file).then(async (file: IFileStatus) => {
                        if (file.isUploaded) {
                            const blogController = new BlogController(req);
                            const result = await blogController.uploadImage(undefined, file.filePath);
                            return res.status(200).send(result);
                        }
                    }).catch(error => {
                        return res.status(400).json({
                            "status": "failed",
                            "code" : "400",
                            "message" : error.message
                        });
                    })
                });
            }
        ]
    }
];