ncc-build.js

const path = require('path');
const fs = require('fs');
const ncc = require('@zeit/ncc');

ncc(path.join(__dirname, 'src', 'index.ts'), {
    // provide a custom cache path or disable caching
    cache: false,
    // externals to leave as requires of the build
    externals: [],
    // directory outside of which never to emit assets
    filterAssetBase: process.cwd(), // default
    minify: false, // default
    sourceMap: true, // default
    sourceMapBasePrefix: '', // default treats sources as output-relative
    // when outputting a sourcemap, automatically include
    // source-map-support in the output file (increases output by 32kB).
    sourceMapRegister: false, // default
    watch: false, // default
    v8cache: false, // default
    quiet: false, // default
    debugLog: false // default
}).then(({
    code,
    map,
    assets
}) => {
    const output_dir = path.join(__dirname, 'lib');
    fs.mkdir(output_dir, {
        recursive: true,
        mode: 0o777
    }, (err) => {
        if (err) {
            console.error(err.toString());
            return;
        }

        fs.writeFile(path.join(output_dir, 'index.js'), code, {
            encoding: 'utf8',
            mode: 0o777
        }, (err) => {
            if (err) {
                console.error(err.toString());
            } else {
                console.log("Written to " + path.join(output_dir, 'index.js'));
            }
        });

        if (map) {
            fs.writeFile(path.join(output_dir, 'index.js.map'), code, {
                encoding: 'utf8',
                mode: 0o777
            }, (err) => {
                if (err) {
                    console.error(err.toString());
                } else {
                    console.log("Written to " + path.join(output_dir, 'index.js.map'));
                }
            });
        }
    });
    // Assets is an object of asset file names to { source, permissions, symlinks }
    // expected relative to the output code (if any)
});