aodb/build/gulp/compile-tests.js

var gulp = require('gulp'),
  config = require('../gulp.config')(),
  tsc = require('gulp-typescript'),
  replace = require('gulp-replace'),
  sourcemaps = require('gulp-sourcemaps');

module.exports = gulp.task('compile-tests', function () {

    gulp.src(config.requiredJavascript).pipe(gulp.dest('./tests/compiled/lib'));

    var result = gulp.src(['./tooling/typings/tsd.d.ts', './app/**/*.ts'])
        .pipe(replace(/\/\/TESTONLY/g, ''))
        .pipe(sourcemaps.init())
        .pipe(tsc({
            target: "ES5",
            module: "commonjs",
            noImplicitAny: false,
            removeComments: true,
            reserveConstEnums: true,
            experimentalDecorators: true
        }));

    return result.js
      .pipe(sourcemaps.write('./'))
       .pipe(replace(/\/\/TESTONLY/g, ''))
      .pipe(replace(/(var __decorate = \(this && this.__decorate\))/g, '$1/* istanbul ignore next */'))
      .pipe(replace(/(var __extends  = \(this && this.__extends \))/g, '$1/* istanbul ignore next */'))
      .pipe(gulp.dest('./tests/compiled'));
});