Actually SeleniumLibrary supports ShadowDom!
The Locator Strategy dom works.
This is what is copied.
document.querySelector("body > settings-ui").shadowRoot.querySelector("#main").shadowRoot.querySelector("settings-basic-page").shadowRoot.querySelector("#basicPage > settings-section:nth-child(3) > settings-people-page").shadowRoot.querySelector("#pages > div > settings-sync-account-control").shadowRoot.querySelector("#avatar-container > img")
Use it like this
Page Should Contain Image dom:document.querySelector("body > settings-ui").shadowRoot.querySelector("#main").shadowRoot.querySelector("settings-basic-page").shadowRoot.querySelector("#basicPage > settings-section:nth-child(3) > settings-people-page").shadowRoot.querySelector("#pages > div > settings-sync-account-control").shadowRoot.querySelector("#avatar-container > img")
This is this cascaded css selectors i was talking about.
This works if the stuff is just there.
Also Get WebElement does work.
But it would be useful to have the parent parameter available.
The capture of the Screenshot is also no problem.
But the dom locator strategy is searching this cascade at one time. I would want to have it pice by pice.
But now i know everything i need!