+abcdefghij << 0 = abcdefghij
abcdefghij << 3 = defghij
+abcdefghij >> 0 = abcdefghij
abcdefghij >> 3 = abcdefg
abcdefghij <<= 5 : fghij
abcdefghij >>= 5 : abcde
+Shift left an empty string: ""
+Shift right an empty string: ""
+abcdefghji << 42 = ""
+abcdefghji >> 42 = ""
PASS string_shift (exit status: 0)