$ perl AngularDifference.t
1..6
ok 1 - zero at zero
ok 2 - zero at 90
ok 3 - 0,45 -> 45
ok 4 - 45,0 -> 45
not ok 5 - 0,270 -> 90, not 270
#     Failed test (AngularDifference.t at line 15)
#          got: '270'
#     expected: '90'
ok 6 - 720,1440+23 -> 23
# Looks like you failed 1 tests of 6.