walk.js/README.md

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# Walk.js (@root/walk)
Walk a directory recursively and handle each entity (files, directories, symlnks, etc).
```js
await Walk.walk(pathname, walkFunc);
function walkFunc(err, pathname, dirent) {
// ...
}
```
This is a port of Go's [`filepath.Walk`](https://golang.org/pkg/path/filepath/#Walk)
for Node.js v10+ (which introduced `fs.readdir` `withFileTypes`) and ES 2021.
# Examples
You can use this with Node v12+ using Vanilla JS or ES2021.
## ES 2021 Modules
`@root/walk` can be used with async/await or Promises.
```js
import { walk } from "@root/walk";
import path from "path";
await walk("./", async (err, pathname, dirent) => {
if (err) {
// throw an error to stop walking
// (or return to ignore and keep going)
console.warn("fs stat error for %s: %s", pathname, err.message);
return;
}
// return false to skip a directory
// (ex: skipping "dot files")
if (dirent.isDirectory() && dirent.name.startsWith(".")) {
return false;
}
// fs.Dirent is a slimmed-down, faster version of fs.Stat
console.log("name:", dirent.name, "in", path.dirname(pathname));
// (only one of these will be true)
console.log("is file?", dirent.isFile());
console.log("is link?", dirent.isSymbolicLink());
});
console.log("Done");
```
## Vanilla JS (ES5)
```js
var Walk = require("@root/walk");
var path = require("path");
Walk.walk("./", function walkFunc(err, pathname, dirent) {
if (err) {
throw err;
}
if (dirent.isDirectory() && dirent.name.startsWith(".")) {
return Promise.resolve(false);
}
console.log("name:", dirent.name, "in", path.dirname(pathname));
return Promise.resolve();
}).then(function () {
console.log("Done");
});
```
# API Documentation
`Walk.walk` walks `pathname` (inclusive) and calls `walkFunc` for each file system entry.
It can be used with Promises:
```js
Walk.walk(pathname, promiseWalker).then(doMore);
```
Or with async / await:
```js
await Walk.walk(pathname, asyncWalker);
```
The behavior should exactly match Go's
[`filepath.Walk`](https://golang.org/pkg/path/filepath/#Walk) with 3 exceptions:
- uses JavaScript Promises/async/await
- receives `dirent` rather than `lstat` (for performance)
<!-- TODO
- can be created with `options` to change default behaviors
-->
## walkFunc
Handles each directory entry
```js
function walker(err, pathname, dirent) {
// `err` is a file system stat error
// `pathname` is the full pathname, including the file name
// `dirent` is an fs.Dirent with a `name`, `isDirectory`, `isFile`, etc
return null;
}
```
<!-- TODO
## create(options)
Create a custom walker with these options:
- `withFileTypes: false` walkFunc will receive String[] instead of fs.Dirent[]
- `sort: sortFunc`
-->