A sample of getStaticProps

sample_getStaticProps.tsx

import { GetStaticProps, GetStaticPropsContext } from 'next'
import { ParsedUrlQuery } from 'querystring';
const db = firebase.firestore()

type Choices = {
  A: string
  B: string
  C: string
  D: string
}

type QuestionType =  {
  id: string
  question: string
  answer: string
  choices: Choices
}

export const getStaticProps: GetStaticProps<QuestionType> = async (context: GetStaticPropsContext<ParsedUrlQuery>) => {
  const id = context.params.id;
  const querySnapShot = await db
    .collection('questions')
    .where('questionId', '==', id)
    .get();

  const question = querySnapShot.docs[0]
  return {
    props: {
      id: question.data().questionId,
      question: question.data().question,
      answer: question.data().correctAnswer,
      choices: question.data().choices,
    },
  };
};