gulpfile.js

var gulp = require('gulp'),
	uglify = require('gulp-uglify'),
	rename = require('gulp-rename'),
	git = require('gulp-git'),
	bump = require('gulp-bump'),
	filter = require('gulp-filter'),
	tag_version = require('gulp-tag-version');

/**
 * Bumping version number and tagging the repository with it.
 * Please read http://semver.org/
 *
 * You can use the commands
 *
 *     gulp patch     # makes v0.1.0 → v0.1.1
 *     gulp feature   # makes v0.1.1 → v0.2.0
 *     gulp release   # makes v0.2.1 → v1.0.0
 *
 * To bump the version numbers accordingly after you did a patch,
 * introduced a feature or made a backwards-incompatible release.
 */
function inc(importance) {
	// get all the files to bump version in
	return gulp.src(['./package.json'])
		// bump the version number in those files
		.pipe(bump({type: importance}))
		// save it back to filesystem
		.pipe(gulp.dest('./'))
		// commit the changed version number
		.pipe(git.commit('bump version'))

		// read only one file to get the version number
		.pipe(filter('package.json'))
		// **tag it in the repository**
		.pipe(tag_version());
}

gulp.task('patch', function() { return inc('patch'); });
gulp.task('minor', function() { return inc('minor'); });
gulp.task('major', function() { return inc('major'); });

gulp.task('build', function() {
	return gulp.src('./src/*.js')
		.pipe(uglify({preserveComments: 'license'}))
		.pipe(rename({ suffix: '.min' }))
		.pipe(gulp.dest('./dist/'));
});