Cannot read properties of undefined (reading 'size') - Next js 13

Question

Today, i come up with one problem that i'm using Next js 13.4 version with backend. so when i used searchParams in server side, it was throwing error: Cannot read properties of undefined (reading 'size') iam destructuring size and style search params. this is my code:

Iam performing add to cart functionlaity, which speaks to backend. this is my addToCart function:

 const addToCartHandler = async () => {
    const style = Number(searchParams.get("style"));
    const size = searchParams.get("size");
    console.log("iam from front", style, Number(size));
    await axios
      .get(`/api/product/${product._id}?style=${style}&size=${size}`)
      .then((res) => console.log("data------>", res.data));       
  };

this is my product/[id]/route.ts:

import { NextResponse } from "next/server";
import connect from "../../../../utils/db";
export const GET = async (
  req: Request,
  { params, searchParams }: { params: any; searchParams: any }
) => {
  try {
    await connect();
    const { id } = params;
    const size = searchParams.size;
    const style = searchParams.style;
    console.log(id, size, style);
    return new NextResponse(id, { status: 200 });
  } catch (error: any) {
    return new NextResponse(`${error}`, {
      status: 500,
      statusText: error.message,
    });
  }
};

I have tried this above code after clicking add to cart button, it throws me

I think there's an error in backend. Please ignore it if you think this is stupid, it's a beginner mistake. :)

Answer 1

In NodeJS's world, searchParams is an object that has many methods and doesn't directly returns a value. In this case, searchParams.size would equan an instance of URLSearchParams object, meaning searchParams equal to an URLSearchParams object, and URLSearchParams.size is undefined.

The right way to fix it would be

    const size = searchParams.get('size');
    const style = searchParams.get('style');

See official NodeJS doc for searchParams here https://nodejs.org/api/url.html#urlsearchparams