folder-hash

What is folder-hash?

The folder-hash npm package is used to generate hash values for the contents of a folder. This can be useful for verifying the integrity of files, detecting changes, and ensuring consistency across different environments.

What are folder-hash's main functionalities?

Generate Hash for a Folder

This feature allows you to generate a hash for the contents of a specified folder. The hash can be used to verify the integrity of the folder's contents.

const folderHash = require('folder-hash');
const options = { folders: { include: ['*'] } };
folderHash.hashElement('path/to/folder', options)
  .then(hash => console.log(hash))
  .catch(error => console.error('Error:', error));

Customizing Hash Options

This feature allows you to customize the hashing options, such as the algorithm, encoding, and which files or folders to include or exclude.

const folderHash = require('folder-hash');
const options = { 
  algo: 'sha256', 
  encoding: 'hex', 
  folders: { exclude: ['node_modules', 'test'] }, 
  files: { include: ['*.js', '*.json'] } 
};
folderHash.hashElement('path/to/folder', options)
  .then(hash => console.log(hash))
  .catch(error => console.error('Error:', error));

Other packages similar to folder-hash

hasha

The hasha package is a versatile hashing library that can hash strings, buffers, and streams. It supports multiple algorithms and is highly configurable. Unlike folder-hash, hasha does not specifically target folder contents but can be used in conjunction with other tools to achieve similar results.

crypto

The built-in Node.js crypto module provides cryptographic functionality, including hashing. While it does not directly support hashing entire folders, it can be used to hash individual files and combined with file system operations to hash folder contents. It offers more control but requires more manual setup compared to folder-hash.

checksum

The checksum package is designed to generate checksums for files and directories. It offers similar functionality to folder-hash but with a focus on simplicity and ease of use. It supports various algorithms and can be a good alternative for basic hashing needs.

README

folderHash

Description

Create a hash checksum over a folder or a file.
The hashes are propagated upwards, the hash that is returned for a folder is generated over all the hashes of its children.
The hashes are generated with the sha1 algorithm and returned in base64 encoding.

The returned information looks like this:

{ name: 'test', 
  hash: 'qmUXLCsTQGOEF6p0w9V78MC7sJI=',
  children: [
    { name: 'helper', 
      hash: 'x1CX3yVH3UuLTw7zcSitSs/PbGE=',
      children: [
        { name: 'helper.js', hash: 'pHYwd8k/oZV01oABTz9MC8KovkU=' }
      ] },
    { name: 'test.js', hash: 'L/vqpdQhxmD5w62k24m4TuZJ1PM=' }
  ] 
}

Each file returns a name and a hash, and each folder returns additionally an array of children (file or folder elements).

Usage

First, install the dependencies by executing npm install.

With promises

var hasher = require('folder-hash');
// pass element name and folder path separately
hasher.hashElement('node_modules', __dirname).then(function (hash) {
    console.log('Result for folder "node_modules" in directory "' + __dirname + '":');
    console.log(hash.toString());
});
// pass element path directly
hasher.hashElement(__dirname).then(function (hash) {
    console.log('Result for folder "' + __dirname + '":');
    console.log(hash.toString());
});

With callbacks

var hasher = require('folder-hash');
// pass element name and folder path separately
hasher.hashElement('node_modules', __dirname, function (error, hash)) {
    if (error) return console.error('hashing failed:', error);
    console.log('Result for folder "node_modules" in directory "' + __dirname + '":');
    console.log(hash.toString());
});
// pass element path directly
hasher.hashElement(__dirname, function (error, hash)) {
    if (error) return console.error('hashing failed:', error);
    console.log('Result for folder "' + __dirname + '":');
    console.log(hash.toString());
});

Behavior

The behavior is documented and verified in the unit tests. Execute npm test or mocha test, and have a look at the test subfolder.

Creating hashes over files

The hashes are the same if:

• A file is checked again
• Two files have the same name and content (but exist in different folders)

The hashes are different if:

• A file was renamed or its content was changed
• Two files have the same name but different content
• Two files have the same content but different names

Creating hashes over folders

Content means in this case a folders children - both the files and the subfolders with their children.

The hashes are the same if:

• A folder is checked again
• Two folders have the same name and content (but have different parent folders)

The hashes are different if:

• A file somewhere in the directory structure was renamed or its content was changed
• Two folders have the same name but different content
• Two folders have the same content but different names

License

MIT, see LICENSE.txt