glob-watcher

[![NPM version][npm-image]][npm-url] [![Downloads][downloads-image]][npm-url] [![Build Status][ci-image]][ci-url] [![Coveralls Status][coveralls-image]][coveralls-url]

Watch globs and execute a function upon change, with intelligent defaults for debouncing and queueing.

Usage

``js
var watch = require('glob-watcher');

watch(['./*.js', '!./something.js'], function (done) {
// This function will be called each time a globbed file is changed
// but is debounced with a 200ms delay (default) and queues subsequent calls

// Make sure to signal async completion with the callback
// or by returning a stream, promise, observable or child process
done();

// if you need access to the path or stat object, listen
// for the change event (see below)

// if you need to listen to specific events, use the returned
// watcher instance (see below)
});

// Raw chokidar instance
var watcher = watch(['./*.js', '!./something.js']);

// Listen for the 'change' event to get path/stat
// No async completion available because this is the raw chokidar instance
watcher.on('change', function (path, stat) {
// path is the path of the changed file
// stat is an fs.Stat object (not always available)
});

// Listen for other events
// No async completion available because this is the raw chokidar instance
watcher.on('add', function (path, stat) {
// path is the path of the changed file
// stat is an fs.Stat object (not always available)
});
`

API

$3

Takes a path string, an array of path strings, a [glob][micromatch] string or an array of [glob][micromatch] strings as globs to watch on the filesystem. Also optionally takes options to configure the watcher and a fn to execute when a file changes.

Note: As of 5.0.0, globs must use / as the separator character because \\ is reserved for escape sequences (as per the Bash 4.3 & Micromatch specs). This means you can't use path.join() or dirnamein Windows environments. If you need to usepath.join(), you can use [normalize-path][normalize-path] against your paths afterwards. If you need to use dirname, you can set it as the cwd option that gets passed directly to [chokidar][chokidar]. The [micromatch docs][micromatch-backslashes] contain more information about backslashes.

Returns an instance of [chokidar][chokidar].

#### fn([callback])

If the fn is passed, it will be called when the watcher emits a change, add or unlink event. It is automatically debounced with a default delay of 200 milliseconds and subsequent calls will be queued and called upon completion. These defaults can be changed using the options.

The fn is passed a single argument, callback, which is a function that must be called when work in the fn is complete. Instead of calling the callback function, [async completion][async-completion] can be signalled by:

- Returning a Stream or EventEmitter
- Returning a Child Process
- Returning a Promise
- Returning an Observable

Once async completion is signalled, if another run is queued, it will be executed.

#### options

##### options.ignoreInitial

If set to false the fn is called during [chokidar][chokidar] instantiation as it discovers the file paths. Useful if it is desirable to trigger the fn during startup.

Passed through to [chokidar][chokidar], but defaulted to true instead of false.

Type: Boolean

Default: true

##### options.delay

The delay to wait before triggering the fn. Useful for waiting on many changes before doing the work on changed files, e.g. find-and-replace on many files.

Type: Number

Default: 200 (milliseconds)

##### options.queue

Whether or not a file change should queue the fn execution if the fn is already running. Useful for a long running fn.

Type: Boolean

Default: true

##### options.events

An event name or array of event names to listen for. Useful if you only need to watch specific events.

Type: String | Array

Default: [ 'add', 'change', 'unlink' ]`

##### other

Options are passed directly to [chokidar][chokidar].

License

MIT

[downloads-image]: https://img.shields.io/npm/dm/glob-watcher.svg?style=flat-square
[npm-url]: https://npmjs.com/package/glob-watcher
[npm-image]: https://img.shields.io/npm/v/glob-watcher.svg?style=flat-square

[ci-url]: https://github.com/gulpjs/glob-watcher/actions?query=workflow:dev
[ci-image]: https://img.shields.io/github/actions/workflow/status/gulpjs/glob-watcher/dev.yml?branch=master&style=flat-square

[coveralls-url]: https://coveralls.io/r/gulpjs/glob-watcher
[coveralls-image]: https://img.shields.io/coveralls/gulpjs/glob-watcher/master.svg?style=flat-square

[micromatch]: https://github.com/micromatch/micromatch
[normalize-path]: https://www.npmjs.com/package/normalize-path
[micromatch-backslashes]: https://github.com/micromatch/micromatch#backslashes
[async-completion]: https://github.com/gulpjs/async-done#completion-and-error-resolution
[chokidar]: https://github.com/paulmillr/chokidar