walker

What is walker?

The `walker` npm package is a tool designed for efficiently walking (traversing) file trees in a Node.js environment. It allows developers to easily perform operations on file systems, such as listing all files in a directory and its subdirectories, filtering files based on certain criteria, and processing each file individually. This package is particularly useful for tasks that involve bulk file operations, such as building a search index, file analysis, or automated file organization.

What are walker's main functionalities?

File Traversal

This feature allows the user to traverse all files starting from a specified directory. It emits events for each file found, enabling the execution of custom logic such as logging or processing of each file.

const walker = require('walker');
const path = '/path/to/start/directory';

walker(path)
  .on('file', function(file, stat) {
    console.log('Found file: ' + file);
  })
  .on('error', function(err, entry) {
    console.error('Error at: ' + entry + ' - ' + err);
  })
  .on('end', function() {
    console.log('All files have been processed');
  });

Directory Filtering

This feature demonstrates how to filter directories during traversal, allowing the user to skip certain directories (e.g., 'node_modules'). This is useful for focusing on relevant files and improving performance by avoiding unnecessary directories.

const walker = require('walker');
const path = '/path/to/start/directory';

walker(path)
  .filterDir(function(dir, stat) {
    // Only traverse directories that are not named 'node_modules'
    return dir.indexOf('node_modules') === -1;
  })
  .on('file', function(file, stat) {
    console.log('Found file: ' + file);
  });

Other packages similar to walker

chokidar

Chokidar is a more feature-rich file watching library that provides a high level of customization and is capable of handling more complex file watching scenarios compared to walker. It supports patterns to watch or ignore specific files and directories and can handle events like add, change, and unlink with more granularity.

glob

Glob is focused on pattern matching rather than file tree traversal. It allows users to specify patterns (using wildcards, for example) to find files matching those patterns. While it doesn't offer the same traversal capabilities as walker, it's very useful for finding files when the structure of the directories is not the primary concern.

readdirp

Readdirp is similar to walker in that it provides recursive directory reading capabilities. However, it offers a promise-based API and additional filtering options, making it a good alternative for modern asynchronous workflows. It's particularly useful for applications that require more control over the file traversal process and prefer promises over event emitters.

README

walker

A nodejs directory walker. Broadcasts events for various file types as well as a generic "entry" event for all types and provides the ability to prune directory trees. This shows the entire API; everything is optional:

Walker('/etc/')
  .filterDir(function(dir, stat) {
    if (dir === '/etc/pam.d') {
      console.warn('Skipping /etc/pam.d and children')
      return false
    }
    return true
  })
  .on('entry', function(entry, stat) {
    console.log('Got entry: ' + entry)
  })
  .on('dir', function(dir, stat) {
    console.log('Got directory: ' + dir)
  })
  .on('file', function(file, stat) {
    console.log('Got file: ' + file)
  })
  .on('symlink', function(symlink, stat) {
    console.log('Got symlink: ' + symlink)
  })
  .on('blockDevice', function(blockDevice, stat) {
    console.log('Got blockDevice: ' + blockDevice)
  })
  .on('fifo', function(fifo, stat) {
    console.log('Got fifo: ' + fifo)
  })
  .on('socket', function(socket, stat) {
    console.log('Got socket: ' + socket)
  })
  .on('characterDevice', function(characterDevice, stat) {
    console.log('Got characterDevice: ' + characterDevice)
  })
  .on('error', function(er, entry, stat) {
    console.log('Got error ' + er + ' on entry ' + entry)
  })
  .on('end', function() {
    console.log('All files traversed.')
  })

You specify a root directory to walk and optionally specify a function to prune sub-directory trees via the filterDir function. The Walker exposes a number of events, broadcasting various file type events a generic error event and finally the event to signal the end of the process.