Found an edge-case when after some intensive scrolling in FireFox - evntObj.deltaY at one point is zero. And since evntObj.wheelDelta is undefined, the wheelDelta variable becomes NaN. Which breaks further scrolling (as visible from screenshots below).
The fix added - falling back on zero, if any of evntObj.deltaY || evntObj.detail || (-1 / 3 * evntObj.wheelDelta) is falsy.
Coverage remained the same at 53.498% when pulling ab9d1f3372b34725ce9ca853133c16cbce2b1f68 on oxala:master into 93c8a51457a67e57a84008d2254f436206cb3098 on wieringen:master.
Found an edge-case when after some intensive scrolling in FireFox -
evntObj.deltaY
at one point is zero. And sinceevntObj.wheelDelta
is undefined, thewheelDelta
variable becomesNaN
. Which breaks further scrolling (as visible from screenshots below).The fix added - falling back on zero, if any of
evntObj.deltaY || evntObj.detail || (-1 / 3 * evntObj.wheelDelta)
is falsy.