Bumper in scroll container #436
Description
I wanted to write a bug report for pat-bumper in the case of scroll containers after I didn't manage to get my bumpers to bump. I've set up an isolated example in this test: https://github.com/Patternslib/bumper-test.
In the bumper example, the strong tags in the left column should stay in place when the user scrolls horizontally within the scroll container.
But just before I wrote this ticket I read this line in the documentation:
In addition it is required that the scrolling container is the first positioned parent of the bumper (i.e. its offset parent).
The above is most likely the reason that my bumper doesn't bump as it's not positioned as a directly child of the scroll container in the DOM tree. The behaviour that I always assumed was that bumper would look for the first ancestor with position auto/scroll on it and if there was none, would assume body as the desired scroll container.
Was there a specific reason we went for this implementation instead? If not, would it be reasonable to let it scan for the first scrolling ancestor instead of only looking at the direct parent?