Session not created Selenium/webdriver when using Safari 12

Question

Since upgrading to Safari 12, my automated scripts are now getting this error:

SessionNotCreatedError: Request body does not contain required parameter \'capabil         


        

Answer 1

This issue happens because Safari 12 uses a new W3C webdriver protocol (source) which appears to be incompatible with the latest stable selenium-webdriver package (v3.6)

safaridriver can be passed a --legacy flag to use the old protocol. Directly on the command line this would be done like: /usr/bin/safaridriver --legacy

This flag can be set on the driver in your node program as follows:

const webdriver = require('selenium-webdriver');
const safari = require('selenium-webdriver/safari');

new webdriver.Builder()
    .usingServer(await new safari.ServiceBuilder().addArguments('--legacy').build().start())
    .forBrowser('safari')
    .build();

Here's documentation on the ServiceBuilder API - https://seleniumhq.github.io/selenium/docs/api/javascript/module/selenium-webdriver/safari_exports_ServiceBuilder.html

A couple GitHub tickets cover this as well:

• https://github.com/SeleniumHQ/selenium/issues/6431
• https://github.com/SeleniumHQ/selenium/issues/6026