Practical Microservices

Reading the Last Message in a Stream

All of our read functions will sit in a file that exports a dependency-receiving function that captures the database connection. Let’s write that shell now:

video-tutorials/src/message-store/read.js

function createRead ({ db }) {
  return {
  }
}

module.exports = exports = createRead

It receives the db and returns… something. Let’s define that something.

Eventide provides a function to get the last message from a stream.^[42] It’s signature is as follows:

CREATE OR REPLACE FUNCTION get_last_stream_message(
  stream_name varchar
)

It just takes a stream name. Here’s some JavaScript to wrap that for our project:

video-tutorials/src/message-store/read.js

const deserializeMessage = require( ...