incognito-page.js

const Page = require('puppeteer/lib/Page');

// the following 2 methods are originally from: https://github.com/GoogleChrome/puppeteer/issues/85#issuecomment-341743259, with some modification to fit puppeteerv1.0.0
async function newPageWithNewContext(browser) {
    const { browserContextId } = await browser._connection.send('Target.createBrowserContext');
    const { targetId } = await browser._connection.send('Target.createTarget', { url: 'about:blank', browserContextId });
    const target = await browser._targets.get(targetId);
    const client = await browser._connection.createSession(targetId);
    const page = await Page.create(client, target, browser._ignoreHTTPSErrors, browser._appMode, browser._screenshotTaskQueue);
    page.browserContextId = browserContextId;
    return page;
}

async function closePage(browser, page) {
    if (page.browserContextId != undefined) {
        await browser._connection.send('Target.disposeBrowserContext', { browserContextId: page.browserContextId });
    }
    await page.close();
}
module.exports = {
    beginIncognito: async browser => {
        let page = await newPageWithNewContext(browser);
        page.endIncognito = async() => closePage(browser, page);
        return page;
    }
};

official API available since v1.5.0: browser.createIncognitoBrowserContext()