testdriver.js provides a means to automate tests that cannot be written purely using web platform APIs.
It is currently supported only for testharness.js tests.
testdriver.js exposes its API through the
test_driver variable in
the global scope.
NB: presently, testdriver.js only works in the top-level test browsing context (and not therefore in any frame or window opened from it).
This function causes a click to occur on the target element (an
Element object), potentially scrolling the document to make it
possible to click it. It returns a
Promise that resolves after the
click has occured or rejects if the element cannot be clicked (for
example, it is obscured by an element on top of it).
Note that if the element to be clicked does not have a unique ID, the document must not have any DOM mutations made between the function being called and the promise settling.