Res.json is not a function

[jalajgoel]

I am trying to use getStaticProps and in that I am fetching data from firebase, so converting it's response to json is throwing error.

getStaticProps

export async function getStaticProps() {
  let res = await getListings();
  if (!!res) {
    // res = { data: res }
    console.log("res", res)
    const post = await res.json();
    return {
      props: { listing: null },
    };
  }
}

getListings() Function

export const getListings = async () => {
  try {
    let query = firebase.collection("listings");
    query = query.orderBy("LastChangeTimestamp", "desc"); //Matrix_Unique_ID
return await query
      .limit(10)
      .get()
      .then(async (res) => {
      return res.docs.map(doc => {
            return doc.data()
        });
  } catch (error) {
    console.error("error getListings =>", error);
    return error;
  }
};

Error is

res.json() is not a function.

[Timer]

You are calling a non-existent method in getStaticProps. The data is already available under the .data key, as seen via your comment.

[HarjaapSinghM]

@jalajgoel did Timer's response help? I'm trying to figure out this exact issue and don't fully understand the answer offered above