Gulp and TypeScript

0-gulpfile.js

// Default 

var gulp = require('gulp');
var ts = require('gulp-typescript');
var tsProject = ts.createProject('tsconfig.json');

gulp.task('default', function () {
    return tsProject.src()
        .pipe(tsProject())
        .js.pipe(gulp.dest('dist'));
});

babel-gulpfile.js

// Babel 

var gulp = require('gulp');
var browserify = require('browserify');
var source = require('vinyl-source-stream');
var tsify = require('tsify');
var sourcemaps = require('gulp-sourcemaps');
var buffer = require('vinyl-buffer');
var paths = {
    pages: ['src/*.html']
};

gulp.task('copy-html', function () {
    return gulp.src(paths.pages)
        .pipe(gulp.dest('dist'));
});

gulp.task('default', gulp.series(gulp.parallel('copy-html'), function () {
    return browserify({
        basedir: '.',
        debug: true,
        entries: ['src/main.ts'],
        cache: {},
        packageCache: {}
    })
    .plugin(tsify)
    .transform('babelify', {
        presets: ['es2015'],
        extensions: ['.ts']
    })
    .bundle()
    .pipe(source('bundle.js'))
    .pipe(buffer())
    .pipe(sourcemaps.init({loadMaps: true}))
    .pipe(sourcemaps.write('./'))
    .pipe(gulp.dest('dist'));
}));

unglify-gulpfile.js

// Uglify 

var gulp = require('gulp');
var browserify = require('browserify');
var source = require('vinyl-source-stream');
var tsify = require('tsify');
var uglify = require('gulp-uglify');
var sourcemaps = require('gulp-sourcemaps');
var buffer = require('vinyl-buffer');
var paths = {
    pages: ['src/*.html']
};

gulp.task('copy-html', function () {
    return gulp.src(paths.pages)
        .pipe(gulp.dest('dist'));
});

gulp.task('default', gulp.series(gulp.parallel('copy-html'), function () {
    return browserify({
        basedir: '.',
        debug: true,
        entries: ['src/main.ts'],
        cache: {},
        packageCache: {}
    })
    .plugin(tsify)
    .bundle()
    .pipe(source('bundle.js'))
    .pipe(buffer())
    .pipe(sourcemaps.init({loadMaps: true}))
    .pipe(uglify())
    .pipe(sourcemaps.write('./'))
    .pipe(gulp.dest('dist'));
}));

watchify-gulpfile.js

 // Watchify 

var gulp = require('gulp');
var browserify = require('browserify');
var source = require('vinyl-source-stream');
var watchify = require('watchify');
var tsify = require('tsify');
var fancy_log = require('fancy-log');
var paths = {
    pages: ['src/*.html']
};

var watchedBrowserify = watchify(browserify({
    basedir: '.',
    debug: true,
    entries: ['src/main.ts'],
    cache: {},
    packageCache: {}
}).plugin(tsify));

gulp.task('copy-html', function () {
    return gulp.src(paths.pages)
        .pipe(gulp.dest('dist'));
});

function bundle() {
    return watchedBrowserify
        .bundle()
        .on('error', fancy_log)
        .pipe(source('bundle.js'))
        .pipe(gulp.dest('dist'));
}

gulp.task('default', gulp.series(gulp.parallel('copy-html'), bundle));
watchedBrowserify.on('update', bundle);
watchedBrowserify.on('log', fancy_log);

Browserify and tsify, we can add various features to our build with browserify plugins.

• Watchify starts gulp and keeps it running, incrementally compiling whenever file saved, to keep an edit-save-refresh cycle in the browser.
• Babel flexible compiler converts ES2015 and beyond into ES5 and ES3 to add extensive and customized transformations that TypeScript doesn’t support.
• Uglify compacts your code so that it takes less time to download.