How can I return Multer Error to Client while using Express-Validator?

Question

Updated Post: Scroll to bottom of post for updated info

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Original Post

I need some help on this one. I'm creating a route that takes FormData, validates the file data via Multer (images in this case), then validates the string data using Express-Validator. I've created a working route that completes both validations, but I can't figure out how to take any errors from Multer and return them to the client.

I have set Multer before Express-Validator, so that the req.body can be read by Express-Validator. With that, I can't figure out how to (or if I'm able at all) to pass in the Multer errors for sending back in the response.

My example below should include everything needed for examination, but if you need additional information, please let me know.

const multer = require('multer')
const {
    check,
    validationResult
} = require('express-validator/check');
const {
    sanitizeBody
} = require('express-validator/filter');


const imageUpload = multer({
    dest: 'uploads/',
    limits: {
        fileSize: 1000000
    },
    fileFilter: function (req, file, cb) {
        let filetypes = /jpeg|jpg/;
        let mimetype = filetypes.test(file.mimetype);
        let extname = filetypes.test(path.extname(file.originalname).toLowerCase());
        if (mimetype && extname) {
            return cb(null, true);
        }
        cb(new Error('Invalid IMAGE Type'))
    }
}).fields([{
        name: 'cover_image',
        maxCount: 1
    },
    {
        name: 'more_images',
        maxCount: 2
    }
])


const validationChecks = [
    check('street', 'Invalid Street Name').matches(/^[a-z0-9 ]+$/i).isLength({
        min: 1,
        max: 25
    }).trim().escape(),
    check('city', 'Invalid City Name').matches(/^[a-z ]+$/i).isLength({
        min: 1,
        max: 15
    }).trim().escape()
]


router.post('/addnewproperty', imageUpload, validationChecks,(req, res, next) => {  
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        console.log('text validation FAILED');
        return res.status(400).json({
            errors: errors.array()
        });
    }
    console.log('validation PASSED');
})

Update 2/6/19

Okay, I think I have found a solution, although not what I expected.

By using the next() function within express, I'm able to utilize Multer in the first route handler where I can receive and send back Multer errors in the response. If no errors arise in this first route handler, I can call next(), to then move along to the next route handler for utilizing express-validator where I can check for and send any errors that arise from string validation.

The code below is a working example of what I'm describing. Not sure if this is acceptable code, but it is working upon some light testing. Any opinions or recommendations on this are welcome in the comments below.

// Here's the meat of what I changed.  
// The config and variables set in the previous code are the same. 

router.post('/addnewproperty',(req, res, next) => {
    imageUpload(req,res,(err)=>{
        if(err){
            console.log(err.message);
            return res.status(400).json(err.message)
        }
        next()
    })
})

router.post('/addnewproperty',validationChecks,(req,res)=>{
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        return res.status(400).json({
            errors: errors.array()
        });
    }
    return res.sendStatus(200)
})

I'll leave this question open in case someone has a better solution of obtaining what I originally set out to do besides the code above.