perf(collections): optimize sortBy

[tomas-zijdemans]

• Optimizes sortBy performance by eliminating wrapper object allocations and reducing redundant computations in the comparison hot path.
• Added more test cases

Benchmark Results:
Tested on Apple M1. Results vary by array size and iteration count, but I observed improvements across all test scenarios on all my various runs. Here's a typical result:

Benchmark	Before	After	Improvement
Numbers (identity selector)	538.27ms	372.90ms	30.7%
Objects by number field	523.60ms	378.41ms	27.7%
Numbers descending	709.18ms	513.22ms	27.6%
Strings by length	58.69ms	43.45ms	26.0%
Already sorted array	64.60ms	48.06ms	25.6%
Reverse sorted array	65.16ms	57.30ms	12.1%
Objects by string field	1162.69ms	1023.97ms	11.9%
Objects by Date field	3232.32ms	2951.31ms	8.7%
Total	6354.53ms	5388.62ms	15.2%

Test script used:

/**
 * Performance benchmark for sortBy
 * Run with: deno run test.ts
 */

import { sortBy } from "@std/collections/sort-by";

const ARRAY_SIZE = 1_000_000;
const ITERATIONS = 50;

function generateTestData() {
  const numbers = Array.from({ length: ARRAY_SIZE }, () => Math.random());

  const objects = Array.from({ length: ARRAY_SIZE }, (_, i) => ({
    id: i,
    value: Math.random(),
    name: `item-${Math.random().toString(36).slice(2, 10)}`,
  }));

  const dates = Array.from({ length: ARRAY_SIZE }, () => ({
    timestamp: new Date(Date.now() - Math.random() * 1e12),
  }));

  const strings = Array.from(
    { length: ARRAY_SIZE },
    () => Math.random().toString(36).slice(2, 12),
  );

  return { numbers, objects, dates, strings };
}

function benchmark(name: string, fn: () => void): number {
  fn();

  const times: number[] = [];
  for (let i = 0; i < ITERATIONS; i++) {
    const start = performance.now();
    fn();
    times.push(performance.now() - start);
  }

  const avg = times.reduce((a, b) => a + b, 0) / times.length;
  const min = Math.min(...times);
  const max = Math.max(...times);

  console.log(
    `  ${name}: avg=${avg.toFixed(2)}ms, min=${min.toFixed(2)}ms, max=${
      max.toFixed(2)
    }ms`,
  );
  return avg;
}

console.log(`\n sortBy Performance Benchmark`);
console.log(`   Array size: ${ARRAY_SIZE.toLocaleString()} elements`);
console.log(`   Iterations: ${ITERATIONS}\n`);

console.log("Generating test data...");
const data = generateTestData();
console.log("Done.\n");

let totalTime = 0;

console.log("Benchmarks:");

totalTime += benchmark("Numbers (identity selector)", () => {
  sortBy(data.numbers, (n) => n);
});

totalTime += benchmark("Objects by number field", () => {
  sortBy(data.objects, (o) => o.value);
});

totalTime += benchmark("Objects by string field", () => {
  sortBy(data.objects, (o) => o.name);
});

totalTime += benchmark("Objects by Date field", () => {
  sortBy(data.dates, (d) => d.timestamp);
});

totalTime += benchmark("Strings by length", () => {
  sortBy(data.strings, (s) => s.length);
});

totalTime += benchmark("Numbers descending", () => {
  sortBy(data.numbers, (n) => n, { order: "desc" });
});

const sorted = [...data.numbers].sort((a, b) => a - b);
totalTime += benchmark("Already sorted array", () => {
  sortBy(sorted, (n) => n);
});

const reversed = [...sorted].reverse();
totalTime += benchmark("Reverse sorted array", () => {
  sortBy(reversed, (n) => n);
});

console.log(`\nTotal average execution time: ${totalTime.toFixed(2)}ms`);

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.17%. Comparing base (13e5527) to head (9d1f709).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #6916   +/-   ##
=======================================
  Coverage   94.17%   94.17%           
=======================================
  Files         584      584           
  Lines       43087    43095    +8     
  Branches     6875     6877    +2     
=======================================
+ Hits        40578    40586    +8     
  Misses       2457     2457           
  Partials       52       52           

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