Take screenshot with Selenium JavaScript driver

SeleniumScreenshot.js

var webdriver = require('selenium-webdriver'),
    By = webdriver.By,
    until = webdriver.until,
    logging = webdriver.logging;
const fs = require('fs');
const path = require('path');


// Take a screenshot. 
// state contains the Selenium driver instance and the config with the default path.
// name is the filename (relative)
function takeScreenshot(state, name) {
    return state
        .driver.takeScreenshot()
        .then(base64PngImage => {
            return state.driver.getCurrentUrl()
                .then(u => {
                    let fname = path.join(state.config.screenshotPath, name);
                    console.info("Writing screenshot: " + fname);
                    fs.writeFileSync(fname, base64PngImage, 'base64');
                });
        })
        .then(_ => state);
}