generate.js

#!/usr/bin/env node

const fs = require('fs');

/**
 * Simple script to generate random data for our mongodb
 * example:
 *    node generate.js <topic_name> <min> <max> <numEntries>
 *
 *    # or
 *
 *    node generate.js <topic_name> <min> <max> <numEntries> true # this will round up the data results
 *
 *    result of the script is written to a file: <topic>.sample.json
 */

// takes in min, max and a bool to round the data
// returns a rand int in the specified range
const rand = (min, max, round = false) =>
  round
    ? Math.floor(Math.random() * (max - min) + min)
    : Math.random() * (max - min) + min;

const data = [];
const topic = process.argv[2];
const min = process.argv[3];
const max = process.argv[4];
const numEntries = process.argv[5];
const round = process.argv[6] && process.argv[5] === 'true';

for (let i = 0; i < numEntries; i++) {
  data.push({
    topic,
    data: [rand(min, max)],
  });
}

fs.writeFileSync(`${topic}.sample.json`, JSON.stringify(data));