Create a new file with gulp

gulpfile.js

var
  gulp              = require('gulp'),
  tap               = require('gulp-tap'),
  path              = require('path'),
  newfile           = require('gulp-file');

gulp.task('new-file', function(){
  gulp.src('./foo.derp')
    .pipe(tap(function(file){
      var fileName = path.basename(file.path) + ".derp";
      var contents = 'hello!';
      return newfile(fileName, contents)
        .pipe(gulp.dest('dist'));
    }));
});