Upload images from array of objects (Multer)

I’ve been struggling with how to grab the images in an array of objects that looks like this:

import mongoose from "mongoose";

const prodcutSchema = new mongoose.Schema(
  {
    title: {
      type: String,
      required: true,
      trim: true,
      lowercase: true,
      unique: true,
    },
    details: [String],
    fits: [String],
    compositions: [String],
    sold: {
      type: Number,
      default: 0,
    },
    colors: [
      {
        coverImage: {
          type: String,
          required: true,
        },
        hoverImage: String,
        images: [String],
        colorName: {
          type: String,
          required: true,
          trim: true,
          lowercase: true,
        },
        colorQuantity: {
          type: Number,
          required: true,
          trim: true,
        },
        discount: {
          type: Number,
          default: 0,
          max: 80,
        },
        sizes: [
          {
            sizeName: {
              type: String,
              required: true,
              trim: true,
              lowercase: true,
            },
            sizeQuantity: {
              type: Number,
              required: true,
              trim: true,
            },
          },
        ],
      },
    ],
    price: {
      type: Number,
      required: true,
      trim: true,
    },
    totalQuantity: {
      type: Number,
      required: true,
      trim: true,
    },
    category: {
      type: mongoose.Schema.ObjectId,
      ref: "Category",
      required: true,
    },
    subcategory: {
      type: mongoose.Schema.ObjectId,
      ref: "Subcategory",
      required: true,
    },
    series: {
      type: mongoose.Schema.ObjectId,
      ref: "Series",
      required: true,
    },
  },
  { timestamps: true }
);

That is the schema of the object, and i dont know how to add that path for the images in my router, i have it like this:

router.post("/", upload.fields([
  {
    name: "coverImage",
    maxCount: 1,
  },
  {
    name: "hoverImage",
    maxCount: 1,
  },
  {
    name: "images",
    maxCount: 3,
  },
]), createProdcutValidation, createProduct);

And is always throwing me an “MulterError: Unexpected field” this is how i send it with postman:
Postman Image
So what is the problem?

“MulterError: Unexpected field” i always get this error!

As files are within an array of objects, .fields() cannot detect fields, and it’s giving that error (fieldname is actually colors[0][coverImage] etc., which is then unexpected…).

You could use .any(), to process all files, and then you could loop req.files and read fieldname property to determine which type of file is it, add counter to replace maxCount, validate etc.

For example:

router.post("/", upload.any(), createProdcutValidation, createProduct);

handle and validate:

req.files.forEach(file => {
  // handle/validate
  console.log(file.fieldname); // e.g. 'colors[0][coverImage]'
});