add more tests

Author: BobTheBuidler

mypyc/test-data/irbuild-constant-fold.test

@@ -490,6 +490,14 @@ def neg_index() -> None:
     a = long_string[-5]
 def slice_index() -> None:
     a = long_string[5:]
+def full_slice() -> None:
+    a = long_string[:]
+def prefix_slice() -> None:
+    a = long_string[:5]
+def mid_slice() -> None:
+    a = long_string[3:5]
+def negative_slice() -> None:
+    a = long_string[-6:-1]
 [out]
 def pos_index():
     r0, a :: str
@@ -509,3 +517,27 @@ L0:
     r0 = 'string'
     a = r0
     return 1
+def full_slice():
+    r0, a :: str
+L0:
+    r0 = 'long string'
+    a = r0
+    return 1
+def prefix_slice():
+    r0, a :: str
+L0:
+    r0 = 'long '
+    a = r0
+    return 1
+def mid_slice():
+    r0, a :: str
+L0:
+    r0 = 'g '
+    a = r0
+    return 1
+def negative_slice():
+    r0, a :: str
+L0:
+    r0 = 'strin'
+    a = r0
+    return 1

mypyc/test-data/run-strings.test

@@ -230,7 +230,14 @@ final_string: Final = "abc"
 final_int: Final = 1
 
 def getitem_folded() -> str:
-    return final_string[final_int] + final_string[-1]
+    return (
+        final_string[final_int]
+        + final_string[-1]
+        + final_string[:]
+        + final_string[:2]
+        + final_string[1:3]
+        + final_string[-3:-1]
+    )
 
 def find(s: str, substr: str, start: Optional[int] = None, end: Optional[int] = None) -> int:
     if start is not None:
@@ -269,7 +276,7 @@ def test_getitem() -> None:
         getitem(s, 4)
     with assertRaises(IndexError, "string index out of range"):
         getitem(s, -4)
-    assert getitem_folded() == "bc"
+    assert getitem_folded() == "bcabcabcbab"
 
 def test_find() -> None:
     s = "abcab"