//  getStaticPaths function
export const getStaticPaths: GetStaticPaths = async () => {
  const res = await fetch("http://localhost:5000/products");
  const products = await res.json();
  const paths = products.map((product: { _id: string }) => ({
    params: { productid: product._id },
  }));
  return { paths, fallback: false };
};

export const getStaticProps: GetStaticProps = async (context) => {
  try {
    const { params } = context;
    const productid = params?.productid as string;
    
    if (!productid) {
      throw new Error('Invalid product id');
    }
    
    const res = await fetch(`http://localhost:5000/products/${productid}`);
    if (!res.ok) {
      throw new Error('Failed to fetch product');
    }
    
    const product: productInterface = await res.json();

    return {
      props: {
        product: product
      },
    };
  } catch (error) {
    console.error('Error fetching product:', error);
    return {
      notFound: true, 
    };
  }
};
    

this is an error

SyntaxError: Unexpected non-whitespace character after JSON at position 4 build . Error: Failed to collect page data for /products/[productid]