Prevent errors from breaking / crashing gulp watch

Question

I\'m running gulp 3.6.2 and have the following task that was set up from a sample online

gulp.task(\'watch\', [\'default\'], function () {
  gulp.watch([
            


        

Answer 1

With one format of files

(ex: *.coffee only)

If you want to work only with one format of files, then gulp-plumber is your solution.

For example rich handled errors and warning for coffeescripting:

gulp.task('scripts', function() {
  return gulp.src(['assets/scripts/**/*.coffee'])
    .pipe(plumber())
    .pipe(coffeelint())
    .pipe(coffeelint.reporter())
    .pipe(lintThreshold(10, 0, lintThresholdHandler))
    .pipe(coffee({
      bare: true
    }))
    .on('error', swallowError)
    .pipe(concat('application.js'))
    .pipe(gulp.dest('dist/scripts'))
    .pipe(rename({ suffix: '.min' }))
    .pipe(uglify())
    .pipe(gulp.dest('dist/scripts'))
    .pipe(notify({ message: 'Scripts task complete' }));
});

With multiple types of file formats

(ex: *.coffee and *.js at same time)

But if you won't to work with multiple types of file formats (for example: *.js and *.coffee), than i will post my solution.

I will just post a self explanatory code over here, with some description before.

gulp.task('scripts', function() {
  // plumber don't fetch errors inside gulpif(.., coffee(...)) while in watch process
  return gulp.src(['assets/scripts/**/*.js', 'assets/scripts/**/*.coffee'])
    .pipe(plumber())
    .pipe(gulpif(/[.]coffee$/, coffeelint()))
    .pipe(coffeelint.reporter())
    .pipe(lintThreshold(10, 0, lintThresholdHandler))
    .pipe(gulpif(/[.]coffee$/, coffee({ // if some error occurs on this step, plumber won't catch it
      bare: true
    })))
    .on('error', swallowError)
    .pipe(concat('application.js'))
    .pipe(gulp.dest('dist/scripts'))
    .pipe(rename({ suffix: '.min' }))
    .pipe(uglify())
    .pipe(gulp.dest('dist/scripts'))
    .pipe(notify({ message: 'Scripts task complete' }));
});

I faced the issue with gulp-plumber and gulp-if using gulp.watch(...

See related issue here: https://github.com/floatdrop/gulp-plumber/issues/23

So the best option for me was:

• Each part as file, and concatenate after. Create multiple tasks that can process each part in separate file (like grunt does), and concatenate them
• Each part as stream, and merge streams after. Merge two streams using merge-stream (that was made from event-stream) into one and continue the job (i tried that first, and it work fine for me, so it is faster solution than previous one)

---

Each part as stream, and merge streams after

Her is the main part of my code:

gulp.task('scripts', function() {
  coffeed = gulp.src(['assets/scripts/**/*.coffee'])
    .pipe(plumber())
    .pipe(coffeelint())
    .pipe(coffeelint.reporter())
    .pipe(lintThreshold(10, 0, lintThresholdHandler))
    .pipe(coffee({
      bare: true
    }))
    .on('error', swallowError);

  jsfiles = gulp.src(['assets/scripts/**/*.js']);

  return merge([jsfiles, coffeed])
    .pipe(concat('application.js'))
    .pipe(gulp.dest('dist/scripts'))
    .pipe(rename({ suffix: '.min' }))
    .pipe(uglify())
    .pipe(gulp.dest('dist/scripts'))
    .pipe(notify({ message: 'Scripts task complete' }));
});

---

Each part as file, and concatenate after

If to separate this into parts, then in each part there should be a result file created. For ex.:

gulp.task('scripts-coffee', function() {

  return gulp.src(['assets/scripts/**/*.coffee'])
    .pipe(plumber())
    .pipe(coffeelint())
    .pipe(coffeelint.reporter())
    .pipe(lintThreshold(10, 0, lintThresholdHandler))
    .pipe(coffee({
      bare: true
    }))
    .on('error', swallowError)
    .pipe(concat('application-coffee.js'))
    .pipe(gulp.dest('dist/scripts'));

});

gulp.task('scripts-js', function() {

  return gulp.src(['assets/scripts/**/*.js'])
    .pipe(concat('application-coffee.js'))
    .pipe(gulp.dest('dist/scripts'));

});

gulp.task('scripts', ['scripts-js', 'scripts-coffee'], function() {

  var re = gulp.src([
    'dist/scripts/application-js.js', 'dist/scripts/application-coffee.js'
  ])
    .pipe(concat('application.js'))
    .pipe(gulp.dest('dist/scripts'))
    .pipe(rename({ suffix: '.min' }))
    .pipe(uglify())
    .pipe(gulp.dest('dist/scripts'))
    .pipe(notify({ message: 'Scripts task complete' }));

  del(['dist/scripts/application-js.js', 'dist/scripts/application-coffee.js']);

  return re;

});

P.S.:

Here node modules and functions that were used:

// Load plugins
var gulp = require('gulp'),
    uglify = require('gulp-uglify'),
    rename = require('gulp-rename'),
    concat = require('gulp-concat'),
    notify = require('gulp-notify'),
    plumber = require('gulp-plumber'),
    merge = require('ordered-merge-stream'),
    replace = require('gulp-replace'),
    del = require('del'),
    gulpif = require('gulp-if'),
    gulputil = require('gulp-util'),
    coffee = require('gulp-coffee'),
    coffeelint = require('gulp-coffeelint),
    lintThreshold = require('gulp-coffeelint-threshold');

var lintThresholdHandler = function(numberOfWarnings, numberOfErrors) {
  var msg;
  gulputil.beep();
  msg = 'CoffeeLint failure; see above. Warning count: ';
  msg += numberOfWarnings;
  msg += '. Error count: ' + numberOfErrors + '.';
  gulputil.log(msg);
};
var swallowError = function(err) {
  gulputil.log(err.toString());
  this.emit('end');
};