laravel-elixir-ts.js

var gulp = require('gulp');
var Elixir = require('laravel-elixir');
var ts = require('gulp-typescript');
var concat = require('gulp-concat');
var _ = require('underscore');

// Laravel Elixir Reporter
var _laravelReporter = require('./reporter');

Elixir.extend('typescript', function(output, dest, options) {
    var search = '**/*.+(ts)';

    options = _.extend({
        sortOutput: true
    }, options);

    new Elixir.Task('typescript', function() {
        var tsResult = gulp.src('./resources/assets/typescript/**/*.ts')
            .pipe(ts(options, undefined, _laravelReporter.ElixirMessage()));
        return tsResult
            .pipe(concat(output))
            .pipe(gulp.dest(dest || './public/js'))
    })
    .watch(Elixir.config.assetsDir + 'typescript' + '/' + search);
});

Recommendation: https://github.com/okaufmann/laravel-elixir-typescript