How to log slow prisma query, tested on Prisma 3

debug-slow-prisma-query.ts

const prismaClient = new PrismaClient({
  log: ['query'] // must enable this to log
});

// Log slow query with all parameters in place,
// so you can copy pasted it and do EXPLAIN query
prismaClient.$on('query' as any, (e: any) => {
  const dur = Number.parseInt(e?.duration);
  const maxQueryTime = 100; // in ms
  if (dur <= maxQueryTime) return;

  console.debug('PRISMA SLOW QUERY >>>', {
    duration: dur,
    query: replaceQuestionMarks(e?.query, e?.params)
  });
});

function replaceQuestionMarks(query: string, args: string): string {
  // add quotes to date
  const queryParamsArray = args.replace(/(\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2} UTC)/g, (match) => {
    return `"${match}"`;
  });

  const paramObjs = JSON.parse(queryParamsArray);

  let replacedQuery = query;
  for (const arg of paramObjs) {
    if (typeof arg === 'number') {
      replacedQuery = replacedQuery.replace('?', `${arg}`);
      continue;
    }
    replacedQuery = replacedQuery.replace('?', `'${arg}'`);
  }
  return replacedQuery;
}