This changes the markdown preview test to use the
waitForSelectorTextChange method rather than waitWhileVisible
because it was not being generated fast enough in some cases
to show correctly with waitWhileVisible.
* In most cases, eslint --fix with the right comma-dangle settings was
able to update the code correctly.
* The exceptions were cases where the parser incorrectly treated the
arguments to functions as lists/objects and added commas; these are
detectable with linters, and we fixed manually. Since this is test
code, we can be reasonably confident that just fixing the failures
suffices to correct any bugs introduced by making changes
automatically.
Chaining together `wait*` functions can create race conditions in the
frontend tests. To avoid race condition, we need to insert `then`
function between two `wait*` functions.
brockwhittaker
Tim Abbott
Steve Howell
hackerkid
Umair Khan