Tzientist demo

index.ts

import * as scientist from 'tzientist';

// Gregory-Leibniz series to calculate Pi
// from https://stackoverflow.com/questions/39574989/calculating-pi-in-javascript-using-gregory-leibniz-series
function oldPi(): number {
  const n = 4000;

  let v = 0;
  for (let i = 1; i <= n; i += 4) {
    v += 1 / i - 1 / (i + 2);
  }
  return 4 * v;
}

function newPi(): number {
  return Math.PI;
}

function publish(results: scientist.Results<[], number>): void {
  if (results.candidateResult !== results.controlResult) {
    console.log(
      `Experiment ${results.experimentName}: expected "${results.controlResult}" but got "${results.candidateResult}"`
    );
  }

  console.log(
    `Control took ${results.controlTimeMs} ms and candidate took ${results.candidateTimeMs} ms`
  );
}

const experiment = scientist.experiment({
  name: 'Pi',
  control: oldPi,
  candidate: newPi,
  options: {
    publish,
  },
});

console.log(`Pi is ${experiment()}`);

package.json

{
  "name": "tzdemo",
  "version": "1.0.0",
  "description": "Tzientist demo",
  "main": "index.js",
  "scripts": {
    "start": "tsc && node index.js"
  },
  "author": "Bill Sorensen",
  "license": "MIT",
  "dependencies": {
    "typescript": "^3.9.3",
    "tzientist": "^2.2.0"
  }
}

tsconfig.json

{
  "compilerOptions": {
    "target": "es5",
    "module": "commonjs",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  }
}