sorted uniq benchmarks

sortedUniqBenchmarks.js

const _ = require('lodash');

// Alter these values to see how it affects the overall performance.
const NUMBER_OF_UNIQUE_ITEMS = 100;
const NUMBER_OF_DUPLICATES_PER_ITEM = 10000;
const TRIALS = 100;

function buildArray() {
  const result = [];
  for (let i = 0; i < NUMBER_OF_UNIQUE_ITEMS; ++i) {
    for (let j = 0; j < NUMBER_OF_DUPLICATES_PER_ITEM; ++j) {
      result.push(i);
    }
  }

  return result;
}

function lodashUniq(array) {
  return _.sortedUniq(array);
}

function unoptimized(array) {
  return [...new Set(array)];
}

function vanillaUniq(array) {
  if (array.length === 0) {
    return [];
  }

  const result = [array[0]];
  for (const value of array) {
    if (result[result.length - 1] !== value) {
      result.push(value);
    }
  }

  return result;
}

function run(...fns) {
  const totals = fns.map(() => 0);
  for (let i = 0; i < TRIALS; ++i) {
    for (const [i, fn] of Object.entries(fns)) {
      const array = buildArray();
      const start = performance.now();
      fn(array);
      const end = performance.now();
      totals[i] += end - start;
    }
  }

  for (const [i, total] of Object.entries(totals)) {
    console.log(`${fns[i].name}: ${total}`);
  }
}

run(lodashUniq, vanillaUniq, unoptimized);