index.ts

const minimalDesc = ["h", "min", "s", "ms", "μs", "ns"];
const verboseDesc = [
  "hour",
  "minute",
  "second",
  "millisecond",
  "microsecond",
  "nanosecond",
];
const convert = [60 * 60, 60, 1, 1e6, 1e3, 1] as const;

export const printHRTime: any = (source: any, opts: any) => {
  let verbose,
    precise,
    i,
    spot,
    sourceAtStep,
    valAtStep,
    decimals,
    strAtStep,
    results,
    totalSeconds;

  verbose = false;
  precise = false;
  if (opts) {
    verbose = opts.verbose || false;
    precise = opts.precise || false;
  }

  if (!Array.isArray(source) || source.length !== 2) {
    return "";
  }
  if (typeof source[0] !== "number" || typeof source[1] !== "number") {
    return "";
  }

  // normalize source array due to changes in node v5.4+
  if (source[1] < 0) {
    totalSeconds = source[0] + source[1] / 1e9;
    source[0] = Math.floor(totalSeconds);
    source[1] = parseFloat((totalSeconds % 1).toPrecision(9)) * 1e9;
  }

  results = "";

  // foreach unit
  for (i = 0; i < 6; i++) {
    spot = i < 3 ? 0 : 1; // grabbing first or second spot in source array
    sourceAtStep = source[spot];
    if (i !== 3 && i !== 0) {
      sourceAtStep = sourceAtStep % (convert[i - 1] as number); // trim off previous portions
    }
    if (i === 2) {
      sourceAtStep += source[1] / 1e9; // get partial seconds from other portion of the array
    }
    valAtStep = sourceAtStep / (convert[i] as number); // val at this unit
    if (valAtStep >= 1) {
      if (verbose) {
        valAtStep = Math.floor(valAtStep); // deal in whole units, subsequent laps will get the decimal portion
      }
      if (!precise) {
        // don't fling too many decimals
        decimals = valAtStep >= 10 ? 0 : 2;
        strAtStep = valAtStep.toFixed(decimals);
      } else {
        strAtStep = valAtStep.toString();
      }
      if (
        strAtStep.indexOf(".") > -1 &&
        strAtStep[strAtStep.length - 1] === "0"
      ) {
        strAtStep = strAtStep.replace(/\.?0+$/, ""); // remove trailing zeros
      }
      if (results) {
        results += " "; // append space if we have a previous value
      }
      results += strAtStep; // append the value
      // append units
      if (verbose) {
        results += " " + verboseDesc[i];
        if (strAtStep !== "1") {
          results += "s";
        }
      } else {
        results += " " + minimalDesc[i];
      }
      if (!verbose) {
        break; // verbose gets as many groups as necessary, the rest get only one
      }
    }
  }

  return results;
};