How to use safari technology preview in webdriver io tests (using wdio test runner)?

Question

I tried running my tests on safari technology preview release 43 (Safari 11.1, WebKit 12605.1.12) using the below desired capabilities in wdio.conf.js.

capabilities: [{
    browserName: 'safari',
    'safari.options': {
        technologyPreview: true
    }
}]

Every time I run the tests, regular version of browser gets opened. Anybody facing similar issue?

Please find the logs below

[14:39:54]  COMMAND    POST      "/wd/hub/session"
[14:39:54]  DATA        {"desiredCapabilities":{"javascriptEnabled":true,"locationContextEnabled":true,"handlesAlerts":true,"rotatable":true,"browserName":"safari","safari.options":{"technologyPreview":true},"loggingPrefs":{"browser":"ALL","driver":"ALL"},"requestOrigins":{"url":"http://webdriver.io","version":"4.6.2","name":"webdriverio"}}}
[14:39:55]  INFO    SET SESSION ID EE19F81D-B054-4926-8235-B64387250665
[14:39:55]  RESULT        {"applicationCacheEnabled":true,"rotatable":false,"databaseEnabled":true,"handlesAlerts":true,"version":"12604.3.5.1.1","cleanSession":true,"platform":"macOS","nativeEvents":true,"locationContextEnabled":false,"webStorageEnabled":true,"browserName":"safari","javascriptEnabled":true,"platformName":"macOS","cssSelectorsEnabled":true}
[14:39:56]  COMMAND    POST      "/wd/hub/session/EE19F81D-B054-4926-8235-B64387250665/url"

Answer 1

It appears as if this is a feature that may not "yet" be supported by Selenium in their Safari Driver implementation.

After researching a little I came across this issue with notes from a few days ago.

https://github.com/SeleniumHQ/selenium/issues/4537

Near the bottom per a member of the Selenium Organization:

Reading "technologyPreview" setting from the node config file is not yet implemented, it's an independent issue, we're working on this feature.