paralleljs/test/specs/performance.spec.js

parallel.js enables easy multi-thread processing in javascript

const os = require('os')
const isCI = require('is-ci')
const isSingleCore = 1 === os.cpus().length;
 
let extraInfo = 'This test is flaky so please rerun. Will be skipped on single core machines and for CI'

if(isSingleCore){
	extraInfo += 'This test has been skipped as its running on a single core machine';
}

if (isCI) {
  console.log('This test has been skipped as its running in a CI enviroment')
}

describe('Performance', () => {
  const isNode = typeof module !== 'undefined' && module.exports;
  const Parallel = isNode ? require('../../lib/parallel.js') : self.Parallel;

  it(`.map() should be using multi-threading (${extraInfo})`, () => {
    if(isCI || isSingleCore){
 	  return;
    }

    const slowSquare = function(n) {
      let i = 0;
      while (++i < n * n) {}
      return i;
    };

    const p = new Parallel([10000, 20000, 30000]);
    const p2 = new Parallel([10000, 20000, 30000]);

    let start;
    let time = null;

    runs(() => {
      start = Date.now();

      p.spawn(data => {
        for (let i = 0; i < data.length; ++i) {
          const n = data[i];
          var square;
          for (square = 0; square < n * n; ++square) {}
          data[i] = square;
        }
        return data;
      }).then(data => {
        time = Date.now() - start;
      });
    });

    waitsFor(() => time !== null, 'Sequential should finish', 5000);

    let start2;
    let time2 = null;

    runs(() => {
      start2 = Date.now();

      p2.map(slowSquare).then(data => {
        time2 = Date.now() - start2;
      });
    });

    waitsFor(() => time2 !== null, 'Parallel should finish', 5000);

    runs(() => {
      expect(time2).toBeLessThan(time * 0.8);
    });
  });
});