js gulp task with config file

jsTask.js

import gulp from 'gulp';
import uglify from 'gulp-uglify';
import eslint from 'gulp-eslint';
import babel from 'gulp-babel';
import concat from 'gulp-concat';
import sourcemaps from 'gulp-sourcemaps';
import gulpif from 'gulp-if';
import globalConfig from './config';

const localConfig = {
  src: './src/js/**/*.js',
  dest: './build/js/',
  buildFileName: 'all.js'
};

gulp.task('js', () =>
  gulp.src(localConfig.src)
    .pipe(gulpif(globalConfig.development(), eslint()))
    .pipe(gulpif(globalConfig.development(), eslint.format()))
    .pipe(gulpif(globalConfig.development(), sourcemaps.init()))
      .pipe(babel())
      .pipe(gulpif(globalConfig.production(), concat(localConfig.buildFileName)))
      .pipe(gulpif(globalConfig.production(), uglify()))
    .pipe(gulpif(globalConfig.development(), sourcemaps.write()))
    .pipe(gulp.dest(localConfig.dest))
);

gulp.task('build', ['js', 'css', 'vendor']);

gulp.task('build:production', ['set-production', 'js', 'css', 'vendor']);

gulp.task('set-production', () => {
  globalConfig.environment = 'production';
});