feat(test): test start out of range

Author: BobTheBuidler

mypyc/test-data/run-strings.test

@@ -828,6 +828,13 @@ def test_count_start() -> None:
     assert string.count("a", 2) == string.count("a", -4) == 0, (string.count("a", 2), string.count("a", -4))
     assert string.count("b", 2) == string.count("b", -4) == 2, (string.count("b", 2), string.count("b", -4))
     assert string.count("c", 2) == string.count("c", -4) == 2, (string.count("c", 2), string.count("c", -4))
+    # out of bounds
+    assert string.count("a", 8) == 0
+    assert string.count("a", -8) == 1
+    assert string.count("b", 8) == 0
+    assert string.count("b", -8) == 3
+    assert string.count("c", 8) == 0
+    assert string.count("c", -8) == 2
 def test_count_start_end() -> None:
     string = "abcbcb"
     assert string.count("a", 0, 4) == 1, string.count("a", 0, 4)
@@ -843,6 +850,13 @@ def test_count_multi_start() -> None:
     assert string.count("aaa", 6) == string.count("aaa", -12) == 0, (string.count("aaa", 6), string.count("aaa", -12))
     assert string.count("bbb", 6) == string.count("bbb", -12) == 2, (string.count("bbb", 6), string.count("bbb", -12))
     assert string.count("ccc", 6) == string.count("ccc", -12) == 2, (string.count("ccc", 6), string.count("ccc", -12))
+    # out of bounds
+    assert string.count("aaa", 20) == 0
+    assert string.count("aaa", -20) == 1
+    assert string.count("bbb", 20) == 0
+    assert string.count("bbb", -20) == 3
+    assert string.count("ccc", 20) == 0
+    assert string.count("ccc", -20) == 2
 def test_count_multi_start_end() -> None:
     string = "aaabbbcccbbbcccbbb"
     assert string.count("aaa", 0, 12) == 1, string.count("aaa", 0, 12)