Browsersync + gulp-watch无法正常工作

Question

In my project i use gulp + browsersync. After update gulp v.4.0.0., browsersync not working and my styles not compiled when watch run (only after in manual restart gulp watch ).

This is my gulpfile.js:

var gulp = require('gulp'),
sass = require('gulp-sass'),
browserSync = require('browser-sync'),
concat = require('gulp-concat'),
uglify = require('gulp-uglifyjs'),
cssnano = require('gulp-cssnano'),
rename = require('gulp-rename'),
del = require('del'),
imagemin = require('gulp-imagemin'),
pngquant = require('imagemin-pngquant'),
autoprefixer = require('gulp-autoprefixer');

gulp.task('sass', function(){
return gulp.src('app/scss/**/*.scss')
    .pipe(sass())
    .pipe(autoprefixer(['last 15 versions', '> 1%'], {cascade: true}))
    .pipe(cssnano())
    .pipe(rename({suffix: '.min'}))
    .pipe(gulp.dest('css'))
    .pipe(browserSync.reload({stream: true}))
 });

gulp.task('css-libs', gulp.parallel('sass'), function(){
return gulp.src('app/css/main.css')
    .pipe(cssnano())
    .pipe(rename({suffix: '.min'}))
    .pipe(gulp.dest('app/css'));
});


gulp.task('browser-sync', function(){
browserSync({
    server: {
        //baseDir: 'app'
        baseDir: './'
    },
    notify:false
})
});


gulp.task('watch', gulp.parallel('browser-sync', 'css-libs'), function(){
gulp.watch('app/scss/*.scss', ['sass']);
gulp.watch('*.html', browserSync.reload);
});

How to fix it?

UPD

This is my package.json

Gulp-watch not working when i change scss file .

Answer 1

I believe your 'watch' task should be rewritten like so:

gulp.task('browser-sync', function(){

  // note the .init

  browserSync.init({
      server: {
          //baseDir: 'app'
          baseDir: './'
      },
      notify:false
  })
});

gulp.task('watch', gulp.parallel('browser-sync', 'css-libs', function(done){

   //   change in the previous line and the following line

  gulp.watch('app/scss/*.scss', gulp.series('sass'));
  gulp.watch('*.html', browserSync.reload);
  done();
}));

so that the function call with the watches is part of the gulp.parallel call. See the parallel tasks documentation and gulp.task signature .

gulp.task('default', gulp.parallel('one', 'two', function(done) {
  // do more stuff
  done();
}));