Why does gulp quit without finishing my task?

Question

I have the following gulp task:

var jade = require('gulp-jade');
var data = require('gulp-data');

gulp.task('jade', function(done) {
  return gulp.src(paths.jade)
    .pipe(data(function(){}))
    .pipe(jade())
    .pipe(gulp.dest('./www/templated/'));
});

Which is trying to compile this jade file:

#{something.anything}

But when I try to run the task, the jade task quits without finishing:

$ gulp jade
[14:39:24] Using gulpfile ~/path/gulpfile.js
[14:39:24] Starting 'jade'...

$

And no output file is generated.

I'm clearly missing something obvious here, but I can't tell what. Searches for 'gulp task not finishing' and the like only yield a lot of results discussing tasks which never finish.

I am running the latest versions of gulp, gulp-jade and gulp-data (3.8.11, 1.0.0 and 1.2.0).

If I remove the pipe to data, everything works. I have tried modifying the call to data, even requiring a valid json file as in the gulp-data example, but it still will not work.

Why is gulp exiting without the task completing and without, seemingly, any error?

Answer 1

The problem is, you have a bug in your .jade file which is causing gulp-jade to throw an error. Ideally, gulp-jade would throw a friendlier gulp error, giving you more info than just a blank screen but, since it's not, you need to handle this error yourself. You can either use gulp-plumber or handle errors coming directly out of that particular pipe manually like so:

var gutil = require('gulp-util');

gulp.task('jade', function() {
  return gulp.src(paths.jade)
    .pipe(jade())
    .on('error', gutil.log)
    .pipe(gulp.dest('./www/templated/'));
});

If you're interested, here are some more details on this error management problem in gulp.