tty-aware-progress/src/index.ts

[](https://travis-ci.org/bkniffler/tty-aware-progress)

import Progress from 'progress';

type IProgress = (numberOfTick?: number) => void;
interface IProgressArgs {
  stream?: NodeJS.WriteStream;
}
function createProgress(
  total: number,
  { stream = process.stderr }: IProgressArgs = {}
): IProgress {
  if (process.stderr.isTTY) {
    const progress = new Progress(
      `[:bar] :current/:total :percent :rate/s :etas `,
      {
        total,
        stream
      }
    );
    return (numberOfTick = 1) => progress.tick(numberOfTick);
  } else {
    let current = 0;
    let percent = 0;
    let start = +new Date();
    return (numberOfTick = 1) => {
      current += numberOfTick;
      const ratio = Math.min(Math.max(current / total, 0), 1);
      const value = Math.floor(ratio * 100);
      if (value !== percent) {
        percent = value;
        const elapsed = +new Date() - start;
        const eta = percent === 100 ? 0 : elapsed * (total / current - 1);
        const rate = current / (elapsed / 1000);
        stream.write(
          `    ${percent}% ${Math.round(rate)}/s ${
            isNaN(eta) || !isFinite(eta) ? '0.0' : (eta / 1000).toFixed(1)
          }s`
        );
      }
    };
  }
}

export default createProgress;