Copy folder recursively in Node.js

Question

Is there an easier way to copy a folder and all its content without manually doing a sequence of fs.readir, fs.readfile, fs.writefile

Answer 1

Yes, ncp is cool though...

You might want/should promisify its function to make it super cool. While you're at it, add it to a tools file to reuse it.

Below is a working version which is Async and uses Promises.

---

File index.js

const {copyFolder} = require('./tools/');

return copyFolder(
    yourSourcePath,
    yourDestinationPath
)
.then(() => {
    console.log('-> Backup completed.')
}) .catch((err) => {
    console.log("-> [ERR] Could not copy the folder: ", err);
})

File tools.js

const ncp = require("ncp");

/**
 * Promise Version of ncp.ncp()
 *
 * This function promisifies ncp.ncp().
 * We take the asynchronous function ncp.ncp() with
 * callback semantics and derive from it a new function with
 * promise semantics.
 */
ncp.ncpAsync = function (sourcePath, destinationPath) {
  return new Promise(function (resolve, reject) {
      try {
          ncp.ncp(sourcePath, destinationPath, function(err){
              if (err) reject(err); else resolve();
          });
      } catch (err) {
          reject(err);
      }
  });
};

/**
 * Utility function to copy folders asynchronously using
 * the Promise returned by ncp.ncp().
 */
const copyFolder = (sourcePath, destinationPath) => {
    return ncp.ncpAsync(sourcePath, destinationPath, function (err) {
        if (err) {
            return console.error(err);
        }
    });
}
module.exports.copyFolder = copyFolder;

Answer 2

This is my approach to solve this problem without any extra modules. Just using the built-in fs and path modules.

Note: This does use the read / write functions of fs, so it does not copy any meta data (time of creation, etc.). As of Node.js 8.5 there is a copyFileSync function available which calls the OS copy functions and therefore also copies meta data. I did not test them yet, but it should work to just replace them. (See https://nodejs.org/api/fs.html#fs_fs_copyfilesync_src_dest_flags)

var fs = require('fs');
var path = require('path');

function copyFileSync( source, target ) {

    var targetFile = target;

    // If target is a directory, a new file with the same name will be created
    if ( fs.existsSync( target ) ) {
        if ( fs.lstatSync( target ).isDirectory() ) {
            targetFile = path.join( target, path.basename( source ) );
        }
    }

    fs.writeFileSync(targetFile, fs.readFileSync(source));
}

function copyFolderRecursiveSync( source, target ) {
    var files = [];

    // Check if folder needs to be created or integrated
    var targetFolder = path.join( target, path.basename( source ) );
    if ( !fs.existsSync( targetFolder ) ) {
        fs.mkdirSync( targetFolder );
    }

    // Copy
    if ( fs.lstatSync( source ).isDirectory() ) {
        files = fs.readdirSync( source );
        files.forEach( function ( file ) {
            var curSource = path.join( source, file );
            if ( fs.lstatSync( curSource ).isDirectory() ) {
                copyFolderRecursiveSync( curSource, targetFolder );
            } else {
                copyFileSync( curSource, targetFolder );
            }
        } );
    }
}

Answer 3

This is pretty easy with Node.js 10:

const FSP = require('fs').promises;

async function copyDir(src,dest) {
    const entries = await FSP.readdir(src, {withFileTypes: true});
    await FSP.mkdir(dest);
    for(let entry of entries) {
        const srcPath = Path.join(src, entry.name);
        const destPath = Path.join(dest, entry.name);
        if(entry.isDirectory()) {
            await copyDir(srcPath, destPath);
        } else {
            await FSP.copyFile(srcPath, destPath);
        }
    }
}

This assumes dest does not exist.

Answer 4

This code will work just fine, recursively copying any folder to any location. But it is Windows only.

var child = require("child_process");
function copySync(from, to){
    from = from.replace(/\//gim, "\\");
    to = to.replace(/\//gim, "\\");
    child.exec("xcopy /y /q \"" + from + "\\*\" \"" + to + "\\\"");
}

It works perfectly for my textbased game for creating new players.

Answer 5

I created a small working example that copies a source folder to another destination folder in just a few steps (based on shift66's answer using ncp):

Step 1 - Install ncp module:

npm install ncp --save

Step 2 - create copy.js (modify the srcPath and destPath variables to whatever you need):

var path = require('path');
var ncp = require('ncp').ncp;

ncp.limit = 16;

var srcPath = path.dirname(require.main.filename); // Current folder
var destPath = '/path/to/destination/folder'; // Any destination folder

console.log('Copying files...');
ncp(srcPath, destPath, function (err) {
  if (err) {
    return console.error(err);
  }
  console.log('Copying files complete.');
});

Step 3 - run

node copy.js

Answer 6

Here's a function that recursively copies a directory and its contents to another directory:

const fs = require("fs")
const path = require("path")

/**
 * Look ma, it's cp -R.
 * @param {string} src  The path to the thing to copy.
 * @param {string} dest The path to the new copy.
 */
var copyRecursiveSync = function(src, dest) {
  var exists = fs.existsSync(src);
  var stats = exists && fs.statSync(src);
  var isDirectory = exists && stats.isDirectory();
  if (isDirectory) {
    fs.mkdirSync(dest);
    fs.readdirSync(src).forEach(function(childItemName) {
      copyRecursiveSync(path.join(src, childItemName),
                        path.join(dest, childItemName));
    });
  } else {
    fs.copyFileSync(src, dest);
  }
};