Pasted

const gulp = require('gulp');
const exec = require('child_process').exec;
const del = require('del');
 
/**
 * Source/Build globs.
 */
const globs = {
    src: './src/**/*.*',
    build: './build/**/*.*',
    lib: './lib/**/*.*'
}
 
/**
 * Cleans the build directory.
 */
gulp.task('clean', () => {
    console.log(`Cleaning files at ${globs.build}`);
    return del([globs.build]);
});
 
/**
 * Runs the TypeScript compiler.
 */
gulp.task('tsc', ['clean'], (done) => {
    exec('tsc --version', (err, stdout, stderr) => {
        console.log(`Compiling using TypeScript ${stdout}`);
        if (stderr) console.warn(stderr);  
    });
 
    return exec('tsc', (err, stdout, stderr) => {
        if (stderr) console.warn(stderr);  
        done(err);
    });
});