fix: adjust copy_with to attempt to use __class_getitem__ as …

…the fallback

instruct/typing.py

@@ -241,6 +241,10 @@ def copy_with(hint: TypeHint, args) -> TypeHint:
             return Union[args]
         if is_copywithable(hint):
             return hint.copy_with(args)
+        type_cls = get_origin(hint)
+        with suppress(AttributeError):
+            if type_cls is not None:
+                return type_cls[args]
         raise NotImplementedError(f"Unable to copy with new type args on {hint!r} ({type(hint)!r})")
 
 else:

tasks.py

@@ -288,13 +288,24 @@ def black(context: Context, check: bool = False):
 
 
 @task
-def test(context: Context, *, verbose: bool = False, fail_fast: bool = False):
+def test(
+    context: Context,
+    *,
+    test_files: Optional[Union[str, List[str], Tuple[str, ...]]] = None,
+    verbose: bool = False,
+    fail_fast: bool = False,
+):
     python_bin = _.python_path(str, silent=True)
     extra = ""
     if verbose:
         extra = f"{extra} -svvv"
     if fail_fast:
         extra = f"{extra} -x"
+    if test_files:
+        if isinstance(test_files, str):
+            test_files = tuple(x.strip() for x in test_files.split(","))
+        f = " ".join(test_files)
+        extra = f"{extra} {f}"
     context.run(f"{python_bin} -m coverage run -m pytest {extra}")
 
 

tests/test_atomic_310.py

@@ -0,0 +1,17 @@
+from instruct import Base, public_class
+
+
+def test_subtraction():
+    class Foo(Base):
+        a: tuple[int, ...]
+        b: str | int
+        c: str
+
+    class FooGroup(Base):
+        foos: list[Foo]
+
+    cls = FooGroup - {"foos": {"a", "b"}}
+
+    ModifiedFoo = public_class(cls, "foos", preserve_subtraction=True)
+
+    assert tuple(ModifiedFoo) == ("c",)