javascript - How do I catch exceptions when a task triggered by gulp-watch fails? -

i use following gulp task transform less css. start once , upon less-file changes updates css.

gulp.task('watch-less', function () {    gulp.watch('app/styles/*.less', function (event) {      try {       var filename = event.path;       gulp.src(filename)         .pipe(sourcemaps.init())         .pipe(less())         .pipe(sourcemaps.write())         .pipe(gulp.dest('app/styles/'));      } catch (e) {       console.log(e);     }   }); }); 

the problem: sometimes, less fails , stops error message like

events.js:72     throw er; // unhandled 'error' event           ^ error: unrecognised input in file  

obviously try catch mechanism wrong, think protects pipe-building step not pipe-running time.

q: how can write gulp-watch task, continues working when less fails?

either go events

gulp.src(filename)     .pipe(sourcemaps.init())     .pipe(less())     .on('error', console.log)     .pipe(sourcemaps.write())     .pipe(gulp.dest('app/styles/')); 

or use gulp-plumber:

 var plumber = require('gulp-plumber')   ...   gulp.src(filename)     .pipe(sourcemaps.init())     .pipe(plumber())     .pipe(less())     .pipe(sourcemaps.write())     .pipe(gulp.dest('app/styles/'));