gulp-watch 
File watcher that uses super-fast chokidar and emits vinyl objects.
npm install --save-dev gulp-watch
var gulp = require('gulp'),
watch = require('gulp-watch');
gulp.task('stream', function () {
// Endless stream mode
return watch('css/**/*.css', { ignoreInitial: false })
.pipe(gulp.dest('build'));
});
gulp.task('callback', function () {
// Callback mode, useful if any plugin in the pipeline depends on the `end`/`flush` event
return watch('css/**/*.css', function () {
gulp.src('css/**/*.css')
.pipe(gulp.dest('build'));
});
});Protip: until gulpjs 4.0 is released, you can use gulp-plumber to prevent stops on errors.
More examples can be found in docs/readme.md.
Creates a watcher that will spy on files that are matched by glob which can be a
glob string or array of glob strings.
Returns a pass through stream that will emit vinyl files
(with additional event property) that corresponds to event on file-system.
This function is called when events happen on the file-system.
All incoming files that are piped in are grouped and passed to the events stream as is.
vinyl— is vinyl object that corresponds to the file that caused the event. Additionaleventfield is added to determine what caused changes.
Possible events:
add- file was added to watch or createdchange- file was changedunlink- file was deleted
This object is passed to the chokidar options directly. Options for gulp.src are also available. If you do not want content from watch, then add read: false to the options object.
options.ignoreInitial
Type: Boolean
Default: true
Indicates whether chokidar should ignore the initial add events or not.
Type: Array
Default: ['add', 'change', 'unlink']
List of events, that should be watched by gulp-watch. Contains event names from chokidar.
Type: String
Default: undefined
Use explicit base path for files from glob. Read more about base and cwd in gulpjs docs.
Type: String
Default: undefined
Name of the watcher. If it is present in options, you will get more readable output.
Type: Boolean
Default: false
This option will enable verbose output.
Type: Number
Default: 10
Wait for readDelay milliseconds before reading the file.
Type: Boolean
Default: true
Setting this to false will return file.contents as null and not read the file at all. Most useful as an optimization if your plugins pipeline doesn't make use of the file contents (e.g. gulp-clean), or to avoid reading the file twice if you use gulp.src() inside the callback instead of the file object that is passed as argument.
Returned Stream from constructor has some useful methods:
add(path / paths)unwatch(path / paths)close()
All events from chokidar:
add,change,unlink,addDir,unlinkDir,error,ready,raw
MIT (c) 2014 Vsevolod Strukchinsky (floatdrop@gmail.com)