gulpfile.js

const gulp = require('gulp')
const ts = require('gulp-typescript')

const STATIC_FILES = ['src/*.json', 'src/**/*.json', 'src/**/*.md']

const tsProject = ts.createProject('tsconfig.json')

gulp.task('compile', () => {
    const tsResult = tsProject.src()
        .pipe(tsProject());
    return tsResult.js.pipe(gulp.dest('dist'))
});

gulp.task('assets', function () {
    return gulp.src(STATIC_FILES)
        .pipe(gulp.dest('dist'));
});

gulp.task('partials', function () {
    return gulp.src(['src/partials/*'])
        .pipe(gulp.dest('dist/partials/'));
});

gulp.task('css', function () {
    return gulp.src(['src/css/*'])
        .pipe(gulp.dest('dist/css/'));
});

gulp.task('img', function () {
    return gulp.src(['src/img/*'])
        .pipe(gulp.dest('dist/img/'));
});

gulp.task('lib', function () {
    return gulp.src(['src/lib/*'])
        .pipe(gulp.dest('dist/lib/'));
});

gulp.task('watch', gulp.series('compile', () => {
    gulp.watch('src/**/*.ts', gulp.series('compile'));
    gulp.watch('src/**/*.json', gulp.series('assets'));
    gulp.watch('src/**/*.md', gulp.series('assets'));
    gulp.watch('src/partials/*', gulp.series('partials'));
    gulp.watch('src/css/*', gulp.series('css'));
    gulp.watch('src/img/*', gulp.series('img'));
    gulp.watch('src/lib/**/*', gulp.series('lib'));
}));

gulp.task('default', gulp.series('watch', 'assets', 'partials', 'css', 'img', 'lib'));