Create Directory When Writing To File In Node.js

Question

Node > 10.12.0

fs.mkdir now accepts a { recursive: true } option like so:

// Creates /tmp/a/apple, regardless of whether `/tmp` and /tmp/a exist.
fs.mkdir('/tmp/a/apple', { recursive: true }, (err) => {
  if (err) throw err;
});

or with a promise:

fs.promises.mkdir('/tmp/a/apple', { recursive: true }).catch(console.error);

Node <= 10.11.0

You can solve this with a package like mkdirp or fs-extra. If you don't want to install a package, please see Tiago Peres França's answer below.

If you don't want to use any additional package, you can call the following function before creating your file:

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

function ensureDirectoryExistence(filePath) {
  var dirname = path.dirname(filePath);
  if (fs.existsSync(dirname)) {
    return true;
  }
  ensureDirectoryExistence(dirname);
  fs.mkdirSync(dirname);
}

With node-fs-extra you can do it easily.

Install it

npm install --save fs-extra

Then use the outputFile method. Its documentation says:

Almost the same as writeFile (i.e. it overwrites), except that if the parent directory does not exist, it's created.

You can use it in four ways.

Async/await

const fse = require('fs-extra');

await fse.outputFile('tmp/test.txt', 'Hey there!');

Using Promises

If you use promises, this is the code:

const fse = require('fs-extra');

fse.outputFile('tmp/test.txt', 'Hey there!')
   .then(() => {
       console.log('The file has been saved!');
   })
   .catch(err => {
       console.error(err)
   });

Callback style

const fse = require('fs-extra');

fse.outputFile('tmp/test.txt', 'Hey there!', err => {
  if(err) {
    console.log(err);
  } else {
    console.log('The file has been saved!');
  }
})

Sync version

If you want a sync version, just use this code:

const fse = require('fs-extra')

fse.outputFileSync('tmp/test.txt', 'Hey there!')

For a complete reference, check the outputFile documentation and all node-fs-extra supported methods.

Shameless plug alert!

You will have to check for each directory in the path structure you want and create it manually if it doesn't exist. All the tools to do so are already there in Node's fs module, but you can do all of that simply with my mkpath module: https://github.com/jrajav/mkpath

Since I cannot comment yet, I'm posting an enhanced answer based on @tiago-peres-frança fantastic solution (thanks!). His code does not make directory in a case where only the last directory is missing in the path, e.g. the input is "C:/test/abc" and "C:/test" already exists. Here is a snippet that works:

function mkdirp(filepath) {
    var dirname = path.dirname(filepath);

    if (!fs.existsSync(dirname)) {
        mkdirp(dirname);
    }

    fs.mkdirSync(filepath);
}

My advise is: try not to rely on dependencies when you can easily do it with few lines of codes

Here's what you're trying to achieve in 14 lines of code:

fs.isDir = function(dpath) {
    try {
        return fs.lstatSync(dpath).isDirectory();
    } catch(e) {
        return false;
    }
};
fs.mkdirp = function(dirname) {
    dirname = path.normalize(dirname).split(path.sep);
    dirname.forEach((sdir,index)=>{
        var pathInQuestion = dirname.slice(0,index+1).join(path.sep);
        if((!fs.isDir(pathInQuestion)) && pathInQuestion) fs.mkdirSync(pathInQuestion);
    });
};