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JavaScript Gulp Basics Gulp your JavaScript Workflow Minifying JavaScript Files

Christopher R
Christopher R
1,441 Points
Posted by Christopher R
Christopher R
1,441 Points

events.js:160 throw er; // Unhandled 'error' even

I'm getting the above error in the console when running gulp minifyScripts:

"use strict";

var gulp = require('gulp'),
  concat = require('gulp-concat'),
  uglify = require('gulp-uglify'),
  rename = require('gulp-rename');

gulp.task("concatScripts", function() {
    gulp.src([
        'js/jquery.js',
        'js/sticky/jquery.sticky.js',
        'js/main.js'
        ])
    .pipe(concat('app.js'))
    .pipe(gulp.dest('js'));
});

gulp.task("minifyScripts", function() {
    gulp.src("js/app.js")
    .pipe(uglify())
    .pipe(rename('app.min.js'))
    .pipe(gulp.dest('js'));
});

gulp.task("default", ["hello"], function() {
    console.log("the default task!!!!");
});

2 Answers

eck
eck
43,038 Points

I think that uglify might be having an error, which is currently not being handled. If you try adding this to the uglify step you might be able to learn more about the nature of your error:

.pipe(uglify().on('error', function(e){
            console.log(e);
         }))
gulp.task("minifyScripts", function() {
    gulp.src("js/app.js")
    .pipe(uglify().on('error', function(e){
       console.log(e);
     }))
    .pipe(rename('app.min.js'))
    .pipe(gulp.dest('js'));
});
eck
eck
43,038 Points

Oh, I think I know where you went wrong. You are running minifyScripts but not the concatScripts task. Adding the concat task to your minify task could be the solution.

gulp.task("minifyScripts", ["concatScripts"], function() {...
eck
eck
43,038 Points

If you pass an array of strings that match other tasks you have declared as the second argument in the gulp.task method then those will be run before that task.