decision expression "in" not working for value 0?

I use the "in" expression when filtering features in a layer.
each feature has a "level" field, and I check in map.setFilter() whether the level is included in the current "selectedLevels" array. however, it never found the level with the number 0, thus never returned true.
I solved the problem, by starting my levels from 1 - but I thought this might be worth pointing out.

mapbox-gl-js version:
v1.8.1

Steps to Trigger Behavior

       var selectedLevels = [0,1,2]

                    [
                        'in',
                        0,
                        ['get', ['literal', 'selectedLevels']]
                    ],

Expected Behavior

return true

Actual Behavior

return false

The issue names map.setFilter() and the "in" expression but no source file or test. Start by reproducing the example on mapbox-gl-js v1.8.1, then trace the expression evaluation path; done means the filter returns true when the selectedLevels array contains 0.