文件移动

目录结构：

├── a.txt
├── b.txt
├── c.txt
├── files
└── index.js

index.js 文件：

const fs = require('fs').promises;
const path = require('path');
/**
 * Move files by directory
 * @param {String} directory
 */
async function moveFilesByDirectory(directory, inputExtname) {
  const dirEntries = await fs.readdir(directory, { withFileTypes: true });
  for (const dirEntry of dirEntries) {
    if (dirEntry.isFile()) {
      const { name: filename, ext } = path.parse(dirEntry.name);
      const extname = ext.split('.').pop().toLocaleLowerCase();
      if (extname === inputExtname) {
        const dir = path.join(directory, filename)
        await mkdir(dir);
        const sourcePath = path.join(directory, dirEntry.name);
        const destPath = path.join(dir, dirEntry.name);
        console.log(sourcePath, destPath);
        await mv(sourcePath, destPath);
      }
    }
  }
}
moveFilesByDirectory('./files', 'txt');
/**
 * Create a directory
 * @param {String} dir
 * @returns 
 */
async function mkdir(dir) {
  if (!(await exists(dir))) {
    await fs.mkdir(dir);
  }
  return dir;
}
/**
 * Check if the file exists
 * @param {String} file 
 * @returns 
 */
async function exists(file) {
  try {
    await fs.access(file);
    return true;
  } catch (err) {
    return false;
  }
}
/**
 * Move
 * @param {String} sourcePath 
 * @param {String} destPath 
 * @returns 
 */
async function mv(sourcePath, destPath) {
  try {
    await fs.rename(sourcePath, destPath);
  } catch (error) {
    if (error.code === 'EXDEV') {
      const readStream = fs.createReadStream(sourcePath);   
      const writeStream = fs.createWriteStream(destPath);
      return new Promise((resolve, reject) => {
        readStream.pipe(writeStream);
        readStream.on('end', onClose);
        readStream.on('error', onError);
        async function onClose() {
          await fsPromises.unlink(sourcePath);
          resolve();
        }
        function onError(err) {
          console.error(`File write failed with message: ${err.message}`);    
          writeStream.close();
          reject(err)
        }
      })
    }
    throw error;
  }
}