instrumentation.js

const benchmarksMap = {};

// benchmarks an individual fn
export const benchmarkFn = (id, fn) => {
  // if id is not a string throw TypeError
  if ("string" !== typeof id) throw new TypeError("id should be a string");
  // if obj is not an object throw an error
  if ("function" !== typeof fn) throw new TypeError("fn should be a function");

  return (...args) => {
    const start = performance.now();
    const res =  fn(...args);
    const end = performance.now();
    const delta = end - start;
    if (!benchmarksMap[id]) {
      benchmarksMap[id] = {
        name: id,
        runs: 1,
        avgTime: delta,
        total: delta
      };
    } else {
      benchmarksMap[id].runs += 1;
      benchmarksMap[id].avgTime = (benchmarksMap[id].avgTime + delta) / 2;
      benchmarksMap[id].total += delta;
    }
    return res;
  };
};

// benchmark all non-class (no-prototype) fns of an object
export const benchmarkAllFns = (id, obj) => {
  // if id is not a string throw TypeError
  if ("string" !== typeof id) throw new TypeError("id should be a string");
  // if obj is not an object throw an error
  if ("object" !== typeof obj) throw new TypeError("obj should be an object");

  const keys = Object.getOwnPropertyNames(obj);
  for (const key of keys) {
    console.log(typeof obj[key] === 'function' && !obj[key].prototype)
    if (typeof obj[key] === 'function') {
     
      obj[key] = benchmarkFn(`${id}-${key}`, obj[key]);
    }
  }
}

// prints a table with benchmark values
export const showBenchmarks = () => {
  console.log(Object.values(benchmarksMap));
  console.table(Object.values(benchmarksMap));
};

window.showBenchmarks = showBenchmarks;