RustPython · youknowone · Jul 12, 2025 · Jul 12, 2025 · Jul 12, 2025 · Jul 12, 2025
diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
@@ -8,26 +8,20 @@
 from collections import UserList
 import random
 
+
 class Sequence:
     def __init__(self, seq='wxyz'): self.seq = seq
     def __len__(self): return len(self.seq)
     def __getitem__(self, i): return self.seq[i]
 
-class BadSeq1(Sequence):
-    def __init__(self): self.seq = [7, 'hello', 123]
-    def __str__(self): return '{0} {1} {2}'.format(*self.seq)
-
-class BadSeq2(Sequence):
-    def __init__(self): self.seq = ['a', 'b', 'c']
-    def __len__(self): return 8
 
 class BaseTest:
     # These tests are for buffers of values (bytes) and not
     # specific to character interpretation, used for bytes objects
     # and various string implementations
 
     # The type to be tested
-    # Change in subclasses to change the behaviour of fixtesttype()
+    # Change in subclasses to change the behaviour of fixtype()
     type2test = None
 
     # Whether the "contained items" of the container are integers in
@@ -36,7 +30,7 @@ class BaseTest:
     contains_bytes = False
 
     # All tests pass their arguments to the testing methods
-    # as str objects. fixtesttype() can be used to propagate
+    # as str objects. fixtype() can be used to propagate
     # these arguments to the appropriate type
     def fixtype(self, obj):
         if isinstance(obj, str):
@@ -160,6 +154,14 @@ def test_count(self):
                     self.assertEqual(rem, 0, '%s != 0 for %s' % (rem, i))
                     self.assertEqual(r1, r2, '%s != %s for %s' % (r1, r2, i))
 
+    # TODO: RUSTPYTHON; TypeError: Unexpected keyword argument count
+    @unittest.expectedFailure
+    def test_count_keyword(self):
+        self.assertEqual('aa'.replace('a', 'b', 0), 'aa'.replace('a', 'b', count=0))
+        self.assertEqual('aa'.replace('a', 'b', 1), 'aa'.replace('a', 'b', count=1))
+        self.assertEqual('aa'.replace('a', 'b', 2), 'aa'.replace('a', 'b', count=2))
+        self.assertEqual('aa'.replace('a', 'b', 3), 'aa'.replace('a', 'b', count=3))
+
     def test_find(self):
         self.checkequal(0, 'abcdefghiabc', 'find', 'abc')
         self.checkequal(9, 'abcdefghiabc', 'find', 'abc', 1)
@@ -327,11 +329,12 @@ def reference_find(p, s):
             for i in range(len(s)):
                 if s.startswith(p, i):
                     return i
+            if p == '' and s == '':
+                return 0
             return -1
 
-        rr = random.randrange
-        choices = random.choices
-        for _ in range(1000):
+        def check_pattern(rr):
+            choices = random.choices
             p0 = ''.join(choices('abcde', k=rr(10))) * rr(10, 20)
             p = p0[:len(p0) - rr(10)] # pop off some characters
             left = ''.join(choices('abcdef', k=rr(2000)))
@@ -341,6 +344,49 @@ def reference_find(p, s):
                 self.checkequal(reference_find(p, text),
                                 text, 'find', p)
 
+        rr = random.randrange
+        for _ in range(1000):
+            check_pattern(rr)
+
+        # Test that empty string always work:
+        check_pattern(lambda *args: 0)
+
+    def test_find_many_lengths(self):
+        haystack_repeats = [a * 10**e for e in range(6) for a in (1,2,5)]
+        haystacks = [(n, self.fixtype("abcab"*n + "da")) for n in haystack_repeats]
+
+        needle_repeats = [a * 10**e for e in range(6) for a in (1, 3)]
+        needles = [(m, self.fixtype("abcab"*m + "da")) for m in needle_repeats]
+
+        for n, haystack1 in haystacks:
+            haystack2 = haystack1[:-1]
+            for m, needle in needles:
+                answer1 = 5 * (n - m) if m <= n else -1
+                self.assertEqual(haystack1.find(needle), answer1, msg=(n,m))
+                self.assertEqual(haystack2.find(needle), -1, msg=(n,m))
+
+    def test_adaptive_find(self):
+        # This would be very slow for the naive algorithm,
+        # but str.find() should be O(n + m).
+        for N in 1000, 10_000, 100_000, 1_000_000:
+            A, B = 'a' * N, 'b' * N
+            haystack = A + A + B + A + A
+            needle = A + B + B + A
+            self.checkequal(-1, haystack, 'find', needle)
+            self.checkequal(0, haystack, 'count', needle)
+            self.checkequal(len(haystack), haystack + needle, 'find', needle)
+            self.checkequal(1, haystack + needle, 'count', needle)
+
+    def test_find_with_memory(self):
+        # Test the "Skip with memory" path in the two-way algorithm.
+        for N in 1000, 3000, 10_000, 30_000:
+            needle = 'ab' * N
+            haystack = ('ab'*(N-1) + 'b') * 2
+            self.checkequal(-1, haystack, 'find', needle)
+            self.checkequal(0, haystack, 'count', needle)
+            self.checkequal(len(haystack), haystack + needle, 'find', needle)
+            self.checkequal(1, haystack + needle, 'count', needle)
+
     def test_find_shift_table_overflow(self):
         """When the table of 8-bit shifts overflows."""
         N = 2**8 + 100
@@ -724,6 +770,18 @@ def test_replace(self):
         self.checkraises(TypeError, 'hello', 'replace', 42, 'h')
         self.checkraises(TypeError, 'hello', 'replace', 'h', 42)
 
+    def test_replace_uses_two_way_maxcount(self):
+        # Test that maxcount works in _two_way_count in fastsearch.h
+        A, B = "A"*1000, "B"*1000
+        AABAA = A + A + B + A + A
+        ABBA = A + B + B + A
+        self.checkequal(AABAA + ABBA,
+                        AABAA + ABBA, 'replace', ABBA, "ccc", 0)
+        self.checkequal(AABAA + "ccc",
+                        AABAA + ABBA, 'replace', ABBA, "ccc", 1)
+        self.checkequal(AABAA + "ccc",
+                        AABAA + ABBA, 'replace', ABBA, "ccc", 2)
+
     @unittest.skip("TODO: RUSTPYTHON, may only apply to 32-bit platforms")
     @unittest.skipIf(sys.maxsize > (1 << 32) or struct.calcsize('P') != 4,
                      'only applies to 32-bit platforms')
@@ -734,8 +792,6 @@ def test_replace_overflow(self):
         self.checkraises(OverflowError, A2_16, "replace", "A", A2_16)
         self.checkraises(OverflowError, A2_16, "replace", "AA", A2_16+A2_16)
 
-
-    # Python 3.9
     def test_removeprefix(self):
         self.checkequal('am', 'spam', 'removeprefix', 'sp')
         self.checkequal('spamspam', 'spamspamspam', 'removeprefix', 'spam')
@@ -754,7 +810,6 @@ def test_removeprefix(self):
         self.checkraises(TypeError, 'hello', 'removeprefix', 'h', 42)
         self.checkraises(TypeError, 'hello', 'removeprefix', ("he", "l"))
 
-    # Python 3.9
     def test_removesuffix(self):
         self.checkequal('sp', 'spam', 'removesuffix', 'am')
         self.checkequal('spamspam', 'spamspamspam', 'removesuffix', 'spam')
@@ -1053,7 +1108,7 @@ def test_splitlines(self):
         self.checkraises(TypeError, 'abc', 'splitlines', 42, 42)
 
 
-class CommonTest(BaseTest):
+class StringLikeTest(BaseTest):
     # This testcase contains tests that can be used in all
     # stringlike classes. Currently this is str and UserString.
 
@@ -1084,11 +1139,6 @@ def test_capitalize_nonascii(self):
         self.checkequal('\u019b\u1d00\u1d86\u0221\u1fb7',
                         '\u019b\u1d00\u1d86\u0221\u1fb7', 'capitalize')
 
-
-class MixinStrUnicodeUserStringTest:
-    # additional tests that only work for
-    # stringlike objects, i.e. str, UserString
-
     def test_startswith(self):
         self.checkequal(True, 'hello', 'startswith', 'he')
         self.checkequal(True, 'hello', 'startswith', 'hello')
@@ -1273,8 +1323,11 @@ def test_join(self):
             self.checkequal(((('a' * i) + '-') * i)[:-1], '-', 'join',
                  ('a' * i,) * i)
 
-        #self.checkequal(str(BadSeq1()), ' ', 'join', BadSeq1())
-        self.checkequal('a b c', ' ', 'join', BadSeq2())
+        class LiesAboutLengthSeq(Sequence):
+            def __init__(self): self.seq = ['a', 'b', 'c']
+            def __len__(self): return 8
+
+        self.checkequal('a b c', ' ', 'join', LiesAboutLengthSeq())
 
         self.checkraises(TypeError, ' ', 'join')
         self.checkraises(TypeError, ' ', 'join', None)
@@ -1459,19 +1512,19 @@ def test_find_etc_raise_correct_error_messages(self):
         # issue 11828
         s = 'hello'
         x = 'x'
-        self.assertRaisesRegex(TypeError, r'^find\(', s.find,
+        self.assertRaisesRegex(TypeError, r'^find\b', s.find,
                                 x, None, None, None)
-        self.assertRaisesRegex(TypeError, r'^rfind\(', s.rfind,
+        self.assertRaisesRegex(TypeError, r'^rfind\b', s.rfind,
                                 x, None, None, None)
-        self.assertRaisesRegex(TypeError, r'^index\(', s.index,
+        self.assertRaisesRegex(TypeError, r'^index\b', s.index,
                                 x, None, None, None)
-        self.assertRaisesRegex(TypeError, r'^rindex\(', s.rindex,
+        self.assertRaisesRegex(TypeError, r'^rindex\b', s.rindex,
                                 x, None, None, None)
-        self.assertRaisesRegex(TypeError, r'^count\(', s.count,
+        self.assertRaisesRegex(TypeError, r'^count\b', s.count,
                                 x, None, None, None)
-        self.assertRaisesRegex(TypeError, r'^startswith\(', s.startswith,
+        self.assertRaisesRegex(TypeError, r'^startswith\b', s.startswith,
                                 x, None, None, None)
-        self.assertRaisesRegex(TypeError, r'^endswith\(', s.endswith,
+        self.assertRaisesRegex(TypeError, r'^endswith\b', s.endswith,
                                 x, None, None, None)
 
         # issue #15534