Performance test to compare different ways to extract the unique items from a big array (in JavaScript)

unique_array.js

const input = Array(7_000_000)
  .fill("")
  .map((_) => Math.floor(Math.random() * 5));

main();

function main() {
  const count = 1000;
  console.log("Running %d iterations", count);
  run_test("FOR   ", unique_with_for, count);
  run_test("SET   ", unique_with_set, count);
  run_test("FOR_OF", unique_with_for_of, count);
  run_test("REDUCE", unique_with_reduce, count);
}

function run_test(label, fn, count) {
  let result = null;
  let total = 0n;
  let lower = 99999999999n;
  let higher = 0n;
  for (let i = 0; i < count; i++) {
    const start = process.hrtime.bigint();
    result = fn(input);
    const end = process.hrtime.bigint(start);
    const duration = end - start;
    if (duration < lower) {
      lower = duration;
    }
    if (duration > higher) {
      higher = duration;
    }
    total += duration;
    // console.log("Done in %d nanoseconds :", end - start, result);
  }
  console.log(
    label + " --- Average: %dms | Lower: %dms | Higher: %dms | Total: %dms",
    parseInt(total / BigInt(count) / BigInt(1_000_000)),
    parseInt(lower / BigInt(1_000_000)),
    parseInt(higher / BigInt(1_000_000)),
    parseInt(total / BigInt(1_000_000))
  );
  //   console.log(result);
}

function unique_with_set(input) {
  return [...new Set(input)];
}

function unique_with_reduce(input) {
  return input.reduce((result, current) => {
    if (result.includes(current)) return result;
    return [...result, current];
  }, []);
}

function unique_with_for(input) {
  const result = [];
  let existing = {};

  for (let entry_index = 0; entry_index < input.length; entry_index++) {
    const entry = input[entry_index];

    if (existing[entry]) continue;

    existing[entry] = true;
    result.push(entry);
  }

  return result;
}

function unique_with_for_of(input) {
  const result = [];
  let existing = {};

  for (const entry of input) {
    if (existing[entry]) continue;

    existing[entry] = true;
    result.push(entry);
  }

  return result;
}