This is a gulp plugin that merges JSON locale files.
npm install gulp-locale-merge --save-dev
var gulp = require('gulp');
var mergeLocale = require('gulp-locale-merge');
gulp.task('locale', function(){
return gulp.src(['locale/application/**/*.json', 'common/locale/**/*.json'])
.pipe(mergeLocale('locale.js'))
.pipe(gulp.dest(`./dist`));
});