Because $test is in double-quotes, your shell is trying to interpolate it. Since it isn't set though (and there aren't such things as warnings and strict for the shell ; ), it is replaced with nothing and becomes:

perl -wMstrict -e"if( my() = 0 ) { print 'Passed'; } else { print 'Fai
+led'; }"
[download]

If you escape the $ you'll be fine.

perl -wMstrict -e"if( my(\$test) = 0 ) { print 'Passed'; } else { prin
+t 'Failed'; }"
[download]