format.js

/**
 * Formats all JS code using Prettier standards
 *
 * Run "yarn format" in command line terminal
 */

'use strict';

// built-in node modules
const fs = require('fs');
const path = require('path');

// third-party node modules
const prettier = require('prettier');
const currentDir = process.cwd(); // the current directory

// ignore these directories
const ignoreDirectories = ['node_modules', '.git', 'redis'];

// methods to detect weather a file is a directory or a .js file
const isDirectory = source => fs.lstatSync(source).isDirectory();
const isJsFile = source => fs.lstatSync(source).isFile() && source.trim().substring(source.length - 3).toLowerCase() === '.js';
const isJsonFile = source => fs.lstatSync(source).isFile() && source.trim().substring(source.length - 5).toLowerCase() === '.json';

// functions to get directories and js files
const getDirectories = source => fs.readdirSync(source).map(name => path.join(source, name)).filter(isDirectory);
const getJsFiles = source => fs.readdirSync(source).map(name => path.join(source, name)).filter(isJsFile);
const getJsonFiles = source => fs.readdirSync(source).map(name => path.join(source, name)).filter(isJsonFile);

// store all the directories to format
let stack = [currentDir];

// format the js files in the current directory and then add the new directories to the stack
function formatDirectory(curDir, options) {
  // get all directory contents
  const directoryContents = fs.readdirSync(curDir);

  // if there are directory contents
  if (directoryContents) {
    // get all directories and JS files in this directory
    const directories = getDirectories(curDir);
    const jsFiles = getJsFiles(curDir);
    const jsonFiles = getJsonFiles(curDir);

    // add directories to stack
    for (let i = 0; i < directories.length; i++) {
      let addDir = true;
      let directory = directories[i];

      // go through the ignoreDirectories
      for (let e = 0; e < ignoreDirectories.length; e++) {
        if (directory.indexOf(ignoreDirectories[e]) >= 0) {
          addDir = false;
          break;
        }
      }

      // if not in ignore directories
      if (addDir)
        stack.push(directory);
    }

    // format js files
    for (let i = 0; i < jsFiles.length; i++) {
      const fileName = jsFiles[i];
      const originalJS = fs.readFileSync(fileName, 'utf8');
      const formattedJS = prettier.format(originalJS, options);

      // write file
      fs.writeFileSync(fileName, formattedJS, { encoding: 'utf8', flag: 'w' });
    }

    // format json files
    for (let i = 0; i < jsonFiles.length; i++) {
      const fileName = jsonFiles[i];
      const originalJson = fs.readFileSync(fileName, 'utf8');

      // USE JSON PARSER
      const formattedJson = prettier.format(originalJson, { parser: 'json' });

      // write file
      fs.writeFileSync(fileName, formattedJson, { encoding: 'utf8', flag: 'w' });
    }
  }
}

// load prettier configuration
prettier.resolveConfig(process.cwd()).then(options => {
  // go through the stack
  while (stack.length)
    formatDirectory(stack.pop(), options);

  console.log('Formatting Finished.');
});