fs.readdir with sync, async, streaming, and async iterator APIs + filtering, recursion, absolute paths, etc.
npm install @jsdevtools/readdir-enhancedEnhanced fs.readdir()
=======================
Features
----------------------------------
- Fully backward-compatible drop-in replacement for fs.readdir() and fs.readdirSync()
- Can crawl sub-directories - you can even control which ones
- Supports filtering results using globs, regular expressions, or custom logic
- Can return absolute paths
- Can return fs.Stats objects rather than just paths
- Exposes additional APIs: Promise, Stream, EventEmitter, and Async Iterator.
Example
----------------------------------
``javascript
import readdir from "@jsdevtools/readdir-enhanced";
import through2 from "through2";
// Synchronous API
let files = readdir.sync("my/directory");
// Callback API
readdir.async("my/directory", (err, files) => { ... });
// Promises API
readdir.async("my/directory")
.then((files) => { ... })
.catch((err) => { ... });
// Async/Await API
let files = await readdir.async("my/directory");
// Async Iterator API
for await (let item of readdir.iterator("my/directory")) {
...
}
// EventEmitter API
readdir.stream("my/directory")
.on("data", (path) => { ... })
.on("file", (path) => { ... })
.on("directory", (path) => { ... })
.on("symlink", (path) => { ... })
.on("error", (err) => { ... });
// Streaming API
let stream = readdir.stream("my/directory")
.pipe(through2.obj(function(data, enc, next) {
console.log(data);
this.push(data);
next();
});
`
Pick Your API
----------------------------------
Readdir Enhanced has multiple APIs, so you can pick whichever one you prefer. Here are some things to consider about each API:
|Function|Returns|Syntax|Blocks the thread?|Buffers results?|
|---|---|---|---|---|
|readdirSync()|Array|Synchronous|yes|yes|readdir()
||Promise|async/await
callback|no|yes|
||Iterator|for await...of|no|no|readdir.stream()
||Readable Stream|stream.on("data")|no|no|
Alias Exports
----------------------------------
The example above imported the readdir default export and used its properties, such as readdir.sync or readdir.async to call specific APIs. For convenience, each of the different APIs is exported as a named function that you can import directly.
- readdir.sync() is also exported as readdirSync()
- is also exported as readdirAsync()
- is also exported as readdirIterator()
- is also exported as readdirStream()
Here's how to import named exports rather than the default export:
`javascript`
import { readdirSync, readdirAsync, readdirIterator, readdirStream } from "@jsdevtools/readdir-enhanced";
Enhanced Features
----------------------------------
Readdir Enhanced adds several features to the built-in fs.readdir() function. All of the enhanced features are opt-in, which makes Readdir Enhanced fully backward compatible by default. You can enable any of the features by passing-in an options argument as the second parameter.
Crawl Subdirectories
----------------------------------
By default, Readdir Enhanced will only return the top-level contents of the starting directory. But you can set the deep option to recursively traverse the subdirectories and return their contents as well.
The deep option can be set to true to traverse the entire directory structure.
`javascript
import readdir from "@jsdevtools/readdir-enhanced";
readdir("my/directory", {deep: true}, (err, files) => {
console.log(files);
// => subdir1
// => subdir1/file.txt
// => subdir1/subdir2
// => subdir1/subdir2/file.txt
// => subdir1/subdir2/subdir3
// => subdir1/subdir2/subdir3/file.txt
});
`
option can be set to a number to only traverse that many levels deep. For example, calling readdir("my/directory", {deep: 2}) will return subdir1/file.txt and subdir1/subdir2/file.txt, but it _won't_ return subdir1/subdir2/subdir3/file.txt.`javascript
import readdir from "@jsdevtools/readdir-enhanced";readdir("my/directory", {deep: 2}, (err, files) => {
console.log(files);
// => subdir1
// => subdir1/file.txt
// => subdir1/subdir2
// => subdir1/subdir2/file.txt
// => subdir1/subdir2/subdir3
});
`$3
For simple use-cases, you can use a regular expression or a glob pattern to crawl only the directories whose path matches the pattern. The path is relative to the starting directory by default, but you can customize this via .> NOTE: Glob patterns _always_ use forward-slashes, even on Windows. This _does not_ apply to regular expressions though. Regular expressions should use the appropraite path separator for the environment. Or, you can match both types of separators using
[\\/].`javascript
import readdir from "@jsdevtools/readdir-enhanced";// Only crawl the "lib" and "bin" subdirectories
// (notice that the "node_modules" subdirectory does NOT get crawled)
readdir("my/directory", {deep: /lib|bin/}, (err, files) => {
console.log(files);
// => bin
// => bin/cli.js
// => lib
// => lib/index.js
// => node_modules
// => package.json
});
`$3
For more advanced recursion, you can set the option to a function that accepts an fs.Stats object and returns a truthy value if the starting directory should be crawled.fs.Stats object that's passed to the function has additional path and depth properties. The path is relative to the starting directory by default, but you can customize this via options.basePath. The depth is the number of subdirectories beneath the base path (see options.deep).`javascript
import readdir from "@jsdevtools/readdir-enhanced";// Crawl all subdirectories, except "node_modules"
function ignoreNodeModules (stats) {
return stats.path.indexOf("node_modules") === -1;
}
readdir("my/directory", {deep: ignoreNodeModules}, (err, files) => {
console.log(files);
// => bin
// => bin/cli.js
// => lib
// => lib/index.js
// => node_modules
// => package.json
});
` option lets you limit the results based on any criteria you want.$3
For simple use-cases, you can use a regular expression or a glob pattern to filter items by their path. The path is relative to the starting directory by default, but you can customize this via options.basePath.> NOTE: Glob patterns _always_ use forward-slashes, even on Windows. This _does not_ apply to regular expressions though. Regular expressions should use the appropraite path separator for the environment. Or, you can match both types of separators using
[\\/].`javascript
import readdir from "@jsdevtools/readdir-enhanced";// Find all .txt files
readdir("my/directory", {filter: "*.txt"});
// Find all package.json files
readdir("my/directory", {filter: "**/package.json", deep: true});
// Find everything with at least one number in the name
readdir("my/directory", {filter: /\d+/});
`$3
For more advanced filtering, you can specify a filter function that accepts an object and returns a truthy value if the item should be included in the results.fs.Stats object that's passed to the filter function has additional path and depth properties. The path is relative to the starting directory by default, but you can customize this via options.basePath. The depth is the number of subdirectories beneath the base path (see options.deep).`javascript
import readdir from "@jsdevtools/readdir-enhanced";// Only return file names containing an underscore
function myFilter(stats) {
return stats.isFile() && stats.path.indexOf("_") >= 0;
}
readdir("my/directory", {filter: myFilter}, (err, files) => {
console.log(files);
// => __myFile.txt
// => my_other_file.txt
// => img_1.jpg
// => node_modules
});
` objects instead of strings
------------------------------------------------------------
All of the Readdir Enhanced functions listed above return an array of strings (paths). But in some situations, the path isn't enough information. Setting the stats option returns an array of fs.Stats objects instead of path strings. The fs.Stats object contains all sorts of useful information, such as the size, the creation date/time, and helper methods such as isFile(), isDirectory(), isSymbolicLink(), etc.fs.Stats objects that are returned also have additional path and depth properties. The path is relative to the starting directory by default, but you can customize this via options.basePath. The depth is the number of subdirectories beneath the base path (see options.deep).`javascript
import readdir from "@jsdevtools/readdir-enhanced";readdir("my/directory", { stats: true }, (err, stats) => {
for (let stat of stats) {
console.log(
${stat.path} was created at ${stat.birthtime});
}
});
`
Base Path
----------------------------------
By default all Readdir Enhanced functions return paths that are relative to the starting directory. But you can use the
option to customize this. The basePath will be prepended to all of the returned paths. One common use-case for this is to set basePath to the absolute path of the starting directory, so that all of the returned paths will be absolute.`javascript
import readdir from "@jsdevtools/readdir-enhanced";
import { resolve } from "path";// Get absolute paths
let absPath = resolve("my/dir");
readdir("my/directory", {basePath: absPath}, (err, files) => {
console.log(files);
// => /absolute/path/to/my/directory/file1.txt
// => /absolute/path/to/my/directory/file2.txt
// => /absolute/path/to/my/directory/subdir
});
// Get paths relative to the working directory
readdir("my/directory", {basePath: "my/directory"}, (err, files) => {
console.log(files);
// => my/directory/file1.txt
// => my/directory/file2.txt
// => my/directory/subdir
});
`
Path Separator
----------------------------------
By default, Readdir Enhanced uses the correct path separator for your OS (
on Windows, / on Linux & MacOS). But you can set the sep option to any separator character(s) that you want to use instead. This is usually used to ensure consistent path separators across different OSes.`javascript
import readdir from "@jsdevtools/readdir-enhanced";// Always use Windows path separators
readdir("my/directory", {sep: "\\", deep: true}, (err, files) => {
console.log(files);
// => subdir1
// => subdir1\file.txt
// => subdir1\subdir2
// => subdir1\subdir2\file.txt
// => subdir1\subdir2\subdir3
// => subdir1\subdir2\subdir3\file.txt
});
`
Custom FS methods
----------------------------------
By default, Readdir Enhanced uses the default Node.js FileSystem module for methods like
, fs.readdir and fs.lstat. But in some situations, you can want to use your own FS methods (FTP, SSH, remote drive and etc). So you can provide your own implementation of FS methods by setting options.fs or specific methods, such as options.fs.stat.`javascript
import readdir from "@jsdevtools/readdir-enhanced";function myCustomReaddirMethod(dir, callback) {
callback(null, ["__myFile.txt"]);
}
let options = {
fs: {
readdir: myCustomReaddirMethod
}
};
readdir("my/directory", options, (err, files) => {
console.log(files);
// => __myFile.txt
});
`
Backward Compatible
-------------------------------------
Readdir Enhanced is fully backward-compatible with Node.js' built-in
and fs.readdirSync() functions, so you can use it as a drop-in replacement in existing projects without affecting existing functionality, while still being able to use the enhanced features as needed.`javascript
import { readdir, readdirSync } from "@jsdevtools/readdir-enhanced";// Use it just like Node's built-in fs.readdir function
readdir("my/directory", (er, files) => { ... });
// Use it just like Node's built-in fs.readdirSync function
let files = readdirSync("my/directory");
`A Note on Streams
----------------------------------
The Readdir Enhanced streaming API follows the Node.js streaming API. A lot of questions around the streaming API can be answered by reading the Node.js documentation.. However, we've tried to answer the most common questions here.
$3
All events in the Node.js streaming API are supported by Readdir Enhanced. These events include "end", "close", "drain", "error", plus more. An exhaustive list of events is available in the Node.js documentation.
#### Detect when the Stream has finished
Using these events, we can detect when the stream has finished reading files.
javascript
import readdir from "@jsdevtools/readdir-enhanced";// Build the stream using the Streaming API
let stream = readdir.stream("my/directory")
.on("data", (path) => { ... });
// Listen to the end event to detect the end of the stream
stream.on("end", () => {
console.log("Stream finished!");
});
`$3
As with all Node.js streams, a Readdir Enhanced stream starts in "paused mode". For the stream to start emitting files, you'll need to switch it to "flowing mode".
There are many ways to trigger flowing mode, such as adding a
handler, using stream.pipe() or calling stream.resume().Unless you trigger flowing mode, your stream will stay paused and you won't receive any file events.
More information on paused vs. flowing mode can be found in the Node.js documentation.
Contributing
--------------------------
Contributions, enhancements, and bug-fixes are welcome! Open an issue on GitHub and submit a pull request.
#### Building
To build the project locally on your computer:
1. __Clone this repo__
git clone https://github.com/JS-DevTools/readdir-enhanced.git2. __Install dependencies__
3. __Run the tests__
License
--------------------------
Readdir Enhanced is 100% free and open-source, under the MIT license. Use it however you want.
This package is Treeware. If you use it in production, then we ask that you buy the world a tree to thank us for our work. By contributing to the Treeware forest you’ll be creating employment for local families and restoring wildlife habitats.
Big Thanks To
--------------------------
Thanks to these awesome companies for their support of Open Source developers ❤
