javascriptnext.jsprismaserializable

Reason: `object` ("[object Date]") cannot be serialized as JSON. Please only return JSON serializable data types


I am using Prisma and Next.js. When I try to retrieve the content from Prisma in getStaticProps it does fetch the data but I can't pass it on to the main component.

export const getStaticProps = async () => {
  const prisma = new PrismaClient();
  const newsLetters = await prisma.newsLetters.findMany();
  console.log(newsLetters);

  return {
    props: {
      newsLetters: newsLetters,
    },
  };
};

As you can see in this image it is fetching as well as printing the content.

enter image description here

But when I pass I get the following error for passing it as props

Reason: `object` ("[object Date]") cannot be serialized as JSON. Please only return JSON serializable data types.

Solution

  • Looks like nextJS doesn't like serializing anything but scalar types for performance reasons. You can read more in this github issue. Best way you can handle this is that you convert your Date objects to UNIX timestamp before returning them.

    // your data
    let newsLetters = [
        {
            id: 'your-id',
            email: 'email@example.com',
            createdAt: new Date()
        }
    ];
    
    // map the array
    newsLetters.map(x => {
        x.createdAt = Math.floor(x.createdAt / 1000);
        return x;
    })
    
    // use newsLetters now
    console.log(newsLetters);