Practical Microservices

Writing Your First Aggregator

Since this is the first Aggregator, here is the basic shape of one:

video-tutorials/src/aggregators/home-page.js

function createHandlers ({ queries }) {
  return {
  }
}


function createQueries ({ db }) {
  return {
  }
}

function build ({ db, messageStore }) {
  const queries = createQueries({ db })
  const handlers = createHandlers({ queries })
  return {
    queries,
    handlers,
  }
}

module.exports = build

Our Aggregators handle messages, so they have handlers. They also interact with a database, so they have queries. There is a top-level function, which we name build that receives dependencies, namely db and messageStore, references to the database and the Message Store, respectively. ...