What is wrong with this code that combines multiple js files to one?

问题

I have this node.js code that tries to minify and combine multiple js files to a single js file.

var concat = require('gulp-concat');
var gulp = require('gulp');

gulp.task('scripts', function() {
    //gulp.src(['./lib/file3.js', './lib/file1.js', './lib/file2.js'])
    gulp.src(['./js/*.js'])
        .pipe(concat('all.js'))
        .pipe(uglify())
        .pipe(gulp.dest('./dist/'))
});

All my js files are located in js folder. My node.js file is above the js folder. I am expecting the single minified file to appear in dist folder. I see nothing and get no error message when I run the code. What could have gone wrong?

回答1:

Gulpfile.js:

"use strict";

var concat = require('gulp-concat');
var gulp = require('gulp');
var uglify = require('gulp-uglify'); // Add gulp-uglify module to your script

gulp.task('scripts', function() {
    gulp.src('./js/*.js')
        .pipe(concat('all.js'))
        .pipe(uglify())
        .pipe(gulp.dest('./dist/'));
});

Check package.json dependencies

Run npm install to verify that all dependencies correctly loaded. I think this was your issue:

{
    "dependencies": {
        "gulp-concat": "2.x",
        "gulp": "3.x",
        "gulp-uglify": "1.x"
    }
}

来源：https://stackoverflow.com/questions/33708893/what-is-wrong-with-this-code-that-combines-multiple-js-files-to-one