gulpfile.js

const gulp = require('gulp');
const tslint = require('tslint');
const gtslint = require('gulp-tslint');
const ts = require('gulp-typescript');
const mocha = require('gulp-mocha');
const sourcemaps = require('gulp-sourcemaps');
const plumber = require('gulp-plumber');
const transform = require('gulp-transform');
const rimraf = require('rimraf');
const merge = require('merge2');
const {preprocess: _preprocess} = require('tiny-preprocessor');

const title = 'yreuq.js';

const tsproj = {
  commonjs: ts.createProject(`./tsconfig.json`, {declaration: true}),
  module: ts.createProject(`./tsconfig.json`, {declaration: true, module: `es2015`}),
  tests: ts.createProject(`./tsconfig.json`, {rootDir: `./`, noUnusedLocals: false})
};

const preprocess = buffer => _preprocess(buffer.toString());

function replace(a, b) {
  return function(buffer) {
    const src = buffer.toString();
    return src.replace(a, b);
  }
}

function compile() {
  const src = gulp.src(`./.build/ts/**/*.ts`)
    .pipe(plumber())
    .pipe(sourcemaps.init());
  const ts_commonjs = src.pipe(tsproj.commonjs());
  const ts_module = src.pipe(tsproj.module());
  return merge([
    ts_commonjs.js
      .pipe(sourcemaps.write(`./`))
      .pipe(gulp.dest(`./lib/commonjs`)),

    ts_module.js
      .pipe(sourcemaps.write(`./`))
      .pipe(gulp.dest(`./lib/module`)),

    ts_module.dts
      .pipe(gulp.dest(`./lib/typings`)),

    gulp.src(`./.build/tests.ts/**/*.ts`)
      .pipe(plumber())
      .pipe(sourcemaps.init())
      .pipe(tsproj.tests()).js
      .pipe(transform(replace(/\.\.\/ts/g, `../../lib/commonjs`)))
      .pipe(sourcemaps.write(`./`))
      .pipe(gulp.dest(`./.build/tests`))
  ]);
}

function runPreprocessor() {
  return merge([
    gulp.src(`./src/**/*.ts`)
      .pipe(plumber())
      .pipe(transform(preprocess))
      .pipe(gulp.dest(`./.build/ts`)),

    gulp.src(`./tests/**/*.ts`)
      .pipe(plumber())
      .pipe(transform(preprocess))
      .pipe(transform(replace(/\.\.\/src/g, `../ts`)))
      .pipe(gulp.dest(`./.build/tests.ts`)),
  ]);
}

function lint() {
  return gulp.src([`./src/**/*.ts`, `./tests/**/*.ts`])
    .pipe(plumber())
    .pipe(gtslint({formatter: "verbose"}))
    .pipe(gtslint.report());
}

function runTests() {
  require(`source-map-support`).install();
  return gulp
    .src([`./.build/tests/**/*.js`], {read: false})
    .pipe(plumber())
    .pipe(mocha({timeout: 10000, ui: `tdd`}));
}

function clean() {
  const paths = [`./lib`, `./.build`];
  return function(cb) {
    const next = (i = 0) => rimraf(paths[i], done(i + 1));
    const done = i => err => err ? cb(err) : i === paths.length ? cb() : next(i);
    return next();
  }
}

gulp.task(`clean`, clean());
gulp.task(`preprocess`, [`lint`], runPreprocessor);
gulp.task(`compile`, [`lint`, `preprocess`], compile);
gulp.task(`watch`, () => gulp.watch([`./src/**/*.ts`, `./tests/**/*.ts`], [`build`]));
gulp.task(`test`, [`compile`], runTests);
gulp.task(`lint`, lint);
gulp.task(`build`, [`preprocess`, `compile`, `test`, `lint`]);
gulp.task(`dev`, [`build`, `watch`]);
gulp.task(`default`, [`build`]);