worker searching using divide and conquer

worker-fun.js

// Uses divide and conquer to find the location of a range of date times within a large array of datetimes.
// It then uses this location to match the date on another array of the same order containing more information about the date.

/* eslint-disable */
const worker = () => {
  function divideAndConquer(lookFor, data, len, order) {
    const half = Math.floor(len - 1 / 2);

    if (!data[half]) return -1;
    if (data[half] === lookFor) return half;

    if (order === 'A' && data[half] < lookFor) {
      return divideAndConquer(lookFor, data.slice(half, half * 2), half, order);
    } else if (order === 'D' && data[half] < lookFor) {
      return divideAndConquer(lookFor, data.slice(0, half), half, order);
    }

    if (order === 'A' && data[half] > lookFor) {
      return divideAndConquer(lookFor, data.slice(0, half), half, order);
    } else if (order === 'D' && data[half] > lookFor) {
      return divideAndConquer(lookFor, data.slice(half, half * 2), half, order);
    }

    return -1;
  }

  self.addEventListener('message', function(e) {
    const {
      len,
      dates,
      dateTimes,
      metrics,
      start,
      end,
    } = e.data;

    const from = divideAndConquer(start, dateTimes, dateTimes.length, 'D');
    const to = divideAndConquer(end, dateTimes, dateTimes.length, 'D');
    const data = {
      dates: dates.slice(from, to).reverse(),
      metrics: metrics.slice(from, to).reverse(),
    };

    self.postMessage(data);
  }, false);
}

let code = worker.toString();
code = code.substring(code.indexOf("{")+1, code.lastIndexOf("}"));

const blob = new Blob([code], {type: "application/javascript"});
const workerScript = URL.createObjectURL(blob);

export {
  workerScript
}

Uses divide and conquer to find the location of a range of date times within a large array of datetimes.
It then uses this location to match the date on another array of the same order containing more information about the date.
Finally it also converts the code into a blob that can be accessed relatively from another file (this is useful when code gets minified into fewer files and to start a web worker you need a separated file)