feat: add algopy.arc4.Struct._replace introduced in algorand-python…

… 2.5.0

src/_algopy_testing/arc4.py

@@ -1096,6 +1096,12 @@ def _as_tuple(self) -> Tuple:  # type: ignore[type-arg]
         tuple_items = tuple(getattr(self, field.name) for field in dataclasses.fields(self))
         return Tuple(tuple_items)
 
+    def _replace(self, **kwargs: typing.Any) -> typing.Self:
+        copy = self.copy()
+        for field, value in kwargs.items():
+            setattr(copy, field, value)
+        return copy
+
 
 class ARC4Client:
     pass

tests/arc4/test_struct.py

@@ -349,6 +349,16 @@ def test_struct_kw_only() -> None:
         StructWithKwOnly(arc4.UInt64(1), arc4.UInt64(2), arc4.Bool(True), arc4.String("hello"))  # type: ignore[misc]
 
 
+def test_replace() -> None:
+    x = StructWithKwOnly(
+        a=arc4.UInt64(1), b=arc4.UInt64(2), c=arc4.Bool(True), d=arc4.String("hello")
+    )
+    y = x._replace(a=arc4.UInt64(2))
+    assert x.a == arc4.UInt64(1)
+    assert y.a == arc4.UInt64(2)
+    assert x != y
+
+
 def _compare_abi_and_arc4_values(
     arc4_value: typing.Any,
     abi_value: typing.Any,