Web DataDog metrics

server.ts

import {StatsD} from 'hot-shots';

const statsd = new Client({
  host: process.env.STATSD_HOST,
  port: process.env.STATSD_PORT,
  prefix: 'ShopifyWeb.',
});

// An array of objects with some details about browser events
// (time to first byte, first paint, etc)
const events = [];

const metrics: [string, any, {[key: string]: string}][] = [];

// Formats all tags into snake case
function formatTags(object: Dictionary<any>) {
  const output: Dictionary<string> = {};

  for (const [key, value] of Object.entries(object)) {
    output[snakeCase(key)] = value == null ? 'unknown' : String(value);
  }

  return output;
}

const tags = {
  ...formatTags({browserConnectionType: connection.effectiveType}),
  ...formatTags(additionalTags),
};

for (const event of events) {
  metrics.push([eventMetricName(event), Math.round(event.start), tags]);
}

const distributions = metrics.map(([metric, value, tags]) => {
  if (development) {
    statsLogger.log(`Skipping sending metric in dev ${metric}: ${value}`);
  } else {
    return statsd.distribution(metric, value, tags);
  }
});

await Promise.all(distributions);