Guard sameish invocation matching against matcher predicate errors

The v2 continuation dedup path compares stubbed invocations in both
matching directions to detect "sameish" signatures. This can evaluate
arg_that predicates against internal matcher objects (for example Any),
which may raise TypeError/ValueError in user predicates.

Treat those exceptions as "not sameish" during continuation detection
instead of failing stubbing. This keeps arg_that behavior unchanged for
normal runtime matching while making internal dedup robust.

Add a regression test in tests/chaining_test.py that reproduces the
failure with arg_that(lambda value: value > 0) next to any().

Ref #119

Author: kaste

mockito/mocking.py

@@ -399,16 +399,28 @@ def set_continuation(self, continuation: invocation.ConfiguredContinuation) -> N
     def _sameish_invocations(
         self, same: invocation.StubbedInvocation
     ) -> list[invocation.StubbedInvocation]:
-        return [
-            invoc
-            for invoc in self.stubbed_invocations
-            if (
-                invoc is not same
-                and invoc.method_name == same.method_name
-                and invoc.matches(same)
-                and same.matches(invoc)
-            )
-        ]
+        sameish: list[invocation.StubbedInvocation] = []
+        for invoc in self.stubbed_invocations:
+            if invoc is same:
+                continue
+
+            if invoc.method_name != same.method_name:
+                continue
+
+            if self._invocations_are_sameish(invoc, same):
+                sameish.append(invoc)
+
+        return sameish
+
+    def _invocations_are_sameish(
+        self,
+        left: invocation.StubbedInvocation,
+        right: invocation.StubbedInvocation,
+    ) -> bool:
+        try:
+            return left.matches(right) and right.matches(left)
+        except Exception:
+            return False
 
     def get_original_method(self, method_name: str) -> object | None:
         return self._original_methods.get(method_name, None)

tests/chaining_test.py

@@ -1,6 +1,7 @@
 import pytest
 
-from mockito import expect, mock, verify, unstub, when
+from mockito import any as any_
+from mockito import arg_that, expect, mock, verify, unstub, when
 from mockito.invocation import AnswerError, InvocationError
 
 
@@ -469,6 +470,16 @@ def test_chain_matching_requires_candidate_matches_existing_direction():
     assert cat.meow(2).purr() == "two"
 
 
+def test_sameish_matching_does_not_evaluate_arg_that_predicate_on_matchers():
+    cat = mock()
+
+    when(cat).meow(any_()).thenReturn("any")
+    when(cat).meow(arg_that(lambda value: value > 0)).thenReturn("positive")
+
+    assert cat.meow(1) == "positive"
+    assert cat.meow(-1) == "any"
+
+
 def test_unexpected_chain_segment_arguments_raise_invocation_error_early():
     cat = mock()