Unfortunately the babel minify-mangle plugin seems to be abandoned and
in certain circumstances can be very buggy. The only safe options are to
disable it, or to switch to a different minification library.
Not minifying our javascript is not ideal, so this commit updates the
javascript tasks to use a rollup, combined with babel, and terser.
Babel still converts code from ES/UMD/AMD to AMD modules with the
relevant browser support, whilst terser minifies the code.
The rollup bundler handles tracking and creation of sourcemaps, and
supports better parallelisation of the tasks.
Since the upgrade to Node LTS/Gallium requires an upgrade to @babel/core
and eslint, which change the built files anyway, this seems like the
ideal time to make this change.
The accessibleChange custom interaction event was only listening for
blur and focus, however some OS/browser combinations do not emit these
events until the element is explicitly blurred. This is notably
different on Firefox on some Operating Systems.
Recent changes in MDL-68167 explicitly moved the user participants page
filter module to use the accessibleChange event, which means that the
selections are now only triggered on an explicit blur when using
Firefox. This highlight a bug whereby, when the mouse is used to make a
selection, the event is not triggered until the element is blurred.
This change modifies the accessibleChange event to ignore the `change`
event where it was triggered by the keyboard and where that keybaord
event was not a [return] or [escape] keypress, but to otherwise respect
the native change event.
The `blur` event does not bubble, but the `focusout` events are not
available in all supported versions of Firefox.
Rather than switching event, this patch using event capture to
effectively achieve the same result and bubble the event up through the
DOM to the delegated listener.
There should be no functional change with this patch, except to support
Firefox fully.
