console-progress-bar/app.js

Console progress bar

// Import.
const cc = require('ccolor');

// Constants.
const MAX_PERCENT_VALUE = 100;
const PROGRESS_BAR_MAX_VALUE = 100;
const PROGRESS_BAR_START_CHARS = ' ';
const PROGRESS_BAR_END_CHARS = ' ';
const PROGRESS_BAR_NOT_FILLED_PART_CHARS = '░';
const PROGRESS_BAR_FILLED_PART_CHARS = ' ';
const PROGRESS_BAR_CHARS_LENGTH = 50;

/**
 * Console progress bar.
 */
class ConsoleProgressBar {
  /**
   * Console progress bar constructor.
   * @param {object} [options] Options.
   * @param {number} [options.maxValue] Max value. Default is 100.
   * @param {string} [options.startChars] Start chars.
   * @param {string} [options.endChars] End chars.
   * @param {string} [options.notFilledPartChars] Not filled part chars.
   * @param {string} [options.filledPartChars] Filled part chars.
   * @param {number} [options.charsLength] Chars length.
   */
  constructor(options = {}) {
    // Define options.
    const defaultOptions = {
      maxValue: PROGRESS_BAR_MAX_VALUE,
      startChars: PROGRESS_BAR_START_CHARS,
      endChars: PROGRESS_BAR_END_CHARS,
      notFilledPartChars: PROGRESS_BAR_NOT_FILLED_PART_CHARS,
      filledPartChars: PROGRESS_BAR_FILLED_PART_CHARS,
      charsLength: PROGRESS_BAR_CHARS_LENGTH
    };
    const progressBarOptions = Object.assign({}, defaultOptions, options);

    // Set options.
    this.value = 0;
    this.percent = -1;
    this.filledParts = -1;
    this.maxValue = progressBarOptions.maxValue;
    this.startChars = progressBarOptions.startChars;
    this.endChars = progressBarOptions.endChars;
    this.notFilledPartChars = progressBarOptions.notFilledPartChars;
    this.filledPartChars = progressBarOptions.filledPartChars;
    this.charsLength = progressBarOptions.charsLength;

    // Show progress bar.
    this.show();
  }

  /**
   * Show.
   */
  show() {
    // Define params.
    this.percent = Math.floor((this.value / this.maxValue) * MAX_PERCENT_VALUE);
    const filledParts = Math.floor((this.value / this.maxValue) * this.charsLength);
    const notFilledParts = this.charsLength - filledParts;
    const filledPartsCharsString = ''.padStart(filledParts, this.filledPartChars);
    const notFilledPartCharsString = ''.padStart(notFilledParts, this.notFilledPartChars);

    // Check if filled parts amount chnaged.
    if (filledParts === this.filledParts) {
      return;
    }
    this.filledParts = filledParts;

    // Show progress bar.
    const progressBarString = `${cc.whiteBackground(this.startChars)}${addColor(filledPartsCharsString, this.percent)}${
      notFilledPartCharsString}${cc.whiteBackground(this.endChars)}`;
    const newLineIfLast = this.percent === MAX_PERCENT_VALUE ? '\n' : '';
    process.stdout.write(`\r${progressBarString}${newLineIfLast}`);
  }

  /**
   * Set value.
   * @param {number} [value] Value.
   */
  setValue(value = this.value) {
    // Check if out of range.
    if (value > this.maxValue) {
      this.value = this.maxValue;
      return;
    }

    // Set as defined.
    this.value = value;

    // Show progress bar.
    this.show();
  }

  /**
   * Add value.
   * @param {number} [value] Value.
   */
  addValue(value = 1) {
    // Define next value.
    const nextValue = this.value + value;

    // Check if out of range.
    if (nextValue > this.maxValue) {
      this.value = this.maxValue;
      return;
    }

    // Set as defined.
    this.value = nextValue;

    // Show progress bar.
    this.show();
  }
}

/**
 * Add color.
 * @param {string} progressBarString Progress bar string.
 * @param {number} percent Percent.
 * @returns {string} Progress bar string with color.
 */
function addColor(progressBarString, percent) {
  // Set color accordance to percent value.
  switch (percent) {
    case 100:
      return cc.greenBackground(progressBarString);
    default:
      return cc.cyanBackground(progressBarString);
  }
}

// Export.
module.exports = ConsoleProgressBar;