Making gulp write files synchronously before moving on to the next task

Question

gulpfile.js

gulp.task(\'browser-bundle\', [\'react\'], function() {
...

});


gulp.task(\'react\', function(){
  gulp.src(options.JSX_SOURCE)
      .pipe(re         


        

Answer 1

back to 2019: if some one come here with similar problem

In gulp 4.*, at least, gulp wait for promise to resolve but ignore the result. so... if you use async await pattern and return the result of gulp.src('...') you got a surprise. the task not wait for stream finish before it continue! somthing that can result to serious bug and waist of time. the solution is "promisify" gulp.src

example:

gulp.task( async function notWaitingTask(){
   // the return stream are ignored because function return promise not stream
   return gulp.src('file.js')
     .pipe(gulp.dest('new-location'))

})

gulp.task( async function waitingTask(){
   // the return stream are respect

   await promisifyStream(
     gulp.src('file.js')
      .pipe(gulp.dest('new-location'))
   )

})

function promisifyStream(stream) {
    return new Promise( res => stream.on('end',res));
}