gulpfile.js

/*---------------------------------------------------------
 * Copyright (C) Microsoft Corporation. All rights reserved.
 *--------------------------------------------------------*/

const gulp = require('gulp');
const path = require('path');
const fs = require('fs');

function verifyNotALinkedModule(modulePath) {
    return new Promise((resolve, reject) => {
        fs.lstat(modulePath, (err, stat) => {
            if (stat.isSymbolicLink()) {
                reject(new Error('Symbolic link found: ' + modulePath));
            } else {
                resolve();
            }
        });
    });
}

function verifyNoLinkedModules() {
    return new Promise((resolve, reject) => {
        fs.readdir('./node_modules', (err, files) => {
            Promise.all(files.map(file => {
                const modulePath = path.join('.', 'node_modules', file);
                return verifyNotALinkedModule(modulePath);
            })).then(resolve, reject);
        });
    });
}

gulp.task('verify-no-linked-modules', cb => verifyNoLinkedModules().then(() => cb, cb));