gulpfile.js

var gulp = require("gulp"),
  watch = require("gulp-watch"),
  tslint = require("gulp-tslint"),
  tsc = require("gulp-typescript");

//******************************************************************************
//* LINT
//******************************************************************************
gulp.task("lint", function() {
  var config = {
    formatter: "verbose",
    emitError: process.env.CI ? true : false
  };

  return gulp
    .src(["src/**/**.ts", "spec/**/**.spec.ts"])
    .pipe(tslint(config))
    .pipe(tslint.report());
});

//******************************************************************************
//* BUILD
//******************************************************************************
var tsLibProject = tsc.createProject("tsconfig.json", {
  module: "commonjs",
  typescript: require("typescript")
});

gulp.task("default", ["build-lib", "build-dts"]);

gulp.task("build-lib", function() {
  return gulp
    .src(["src/**/*.ts"])
    .pipe(tsLibProject())
    .on("error", function(err) {
      process.exit(1);
    })
    .js.pipe(gulp.dest("lib/"));
});

var tsDtsProject = tsc.createProject("tsconfig.json", {
  declaration: true,
  noResolve: false,
  typescript: require("typescript")
});

gulp.task("build-dts", function() {
  return gulp
    .src(["src/**/*.ts"])
    .pipe(tsDtsProject())
    .on("error", function(err) {
      process.exit(1);
    })
    .dts.pipe(gulp.dest("dts"));
});

//******************************************************************************
//* WATCH
//******************************************************************************
gulp.task("watch", function () {
  return watch("src/**/*.ts", function () {
    gulp
      .src(["src/**/*.ts"])
      .pipe(tsLibProject())
      .on("error", function (err) {
        process.exit(1);
      })
      .js.pipe(gulp.dest("lib/"));

    gulp
      .src(["src/**/*.ts"])
      .pipe(tsDtsProject())
      .on("error", function (err) {
        process.exit(1);
      })
      .dts.pipe(gulp.dest("dts"))
  });
});