A selector like `$('.elem1 .elem2:first')` selects the first descendant
with class name `.elem2` under `.elem1`. This is the same as saying
`$('.elem1 .elem2').first()`. See example here:
https://jsbin.com/bohehesari/edit?html,js,output
User was able to click delete button multiple time which could cause
multiple delete requests. This commit disables and hides the delete
message button after the first click and shows a spinner until http
the delete request responds.
Also adds a casperjs test to ensure that spinner becomes visible and
delete button becomes invisible after clicking on delete button for
first time and hides spinner and show delete buttton when message is
deleted.
Fixes: #11219.
We now specifically wait for the length to decrease by one. This seems
like a more deterministic condition to wait on.
Previously we were waiting till the id of the deleted message remained
visible; intuitively, this should have worked but it seems that there
is some race condition that was causing the test to fail sporadically.
This makes it possible for Zulip administrators to delete messages.
This is primarily intended for use in deleting early test messages,
but it can solve other problems as well.
Later we'll want to play with the permissions model for this, but for
now, the goal is just to integrate the feature.
Note that it saves the deleted messages for some time using the same
approach as Zulip's message retention policy feature.
Fixes#135.
Thomas Ip
Mohit Gupta
Umair Khan
K.Kanakhin