Support types from PEP 585, 604

dcargs/_resolver.py

@@ -1,14 +1,16 @@
 """Utilities for resolving types and forward references."""
-
 import collections.abc
 import copy
 import dataclasses
+import sys
 from typing import (
     Any,
     Callable,
     Dict,
+    FrozenSet,
     List,
     Optional,
+    Set,
     Tuple,
     Type,
     TypeVar,
@@ -171,6 +173,25 @@ def apply_type_from_typevar(
         if get_origin(typ) is collections.abc.Callable:
             assert isinstance(args[0], list)
             args = tuple(args[0]) + args[1:]
+
+        # Convert Python 3.10-style types to their typing library equivalents, which
+        # support `.copy_with()`.
+        if sys.version_info[:2] >= (3, 10):
+            import types
+
+            for new, old in {
+                # PEP 585
+                tuple: Tuple,
+                list: List,
+                dict: Dict,
+                set: Set,
+                frozenset: FrozenSet,
+                # PEP 604
+                types.UnionType: Union,
+            }.items():
+                if isinstance(typ, new) or get_origin(typ) is new:  # type: ignore
+                    typ = old.__getitem__(args)  # type: ignore
+
         return typ.copy_with(tuple(apply_type_from_typevar(x, type_from_typevar) for x in args))  # type: ignore
 
     return typ

tests/test_new_style_annotations_only_py310.py

@@ -0,0 +1,60 @@
+import dataclasses
+from typing import Any, Literal
+
+import pytest
+
+import dcargs
+
+
+def test_union_basic():
+    def main(x: int | str) -> int | str:
+        return x
+
+    assert dcargs.cli(main, args=["--x", "5"]) == 5
+    assert dcargs.cli(main, args=["--x", "6"]) == 6
+    assert dcargs.cli(main, args=["--x", "five"]) == "five"
+
+
+def test_union_with_list():
+    def main(x: int | str | list[bool]) -> Any:
+        return x
+
+    assert dcargs.cli(main, args=["--x", "5"]) == 5
+    assert dcargs.cli(main, args=["--x", "6"]) == 6
+    assert dcargs.cli(main, args=["--x", "five"]) == "five"
+    assert dcargs.cli(main, args=["--x", "True"]) == "True"
+    assert dcargs.cli(main, args=["--x", "True", "False"]) == [True, False]
+
+
+def test_union_literal():
+    def main(x: Literal[1, 2] | Literal[3, 4, 5] | str) -> int | str:
+        return x
+
+    assert dcargs.cli(main, args=["--x", "5"]) == 5
+    assert dcargs.cli(main, args=["--x", "6"]) == "6"
+    assert dcargs.cli(main, args=["--x", "five"]) == "five"
+
+
+def test_super_nested():
+    def main(
+        x: None
+        | list[
+            tuple[
+                None | int,
+                Literal[3, 4],
+                tuple[int, int] | tuple[str, str],
+            ]
+        ] = None
+    ) -> Any:
+        return x
+
+    assert dcargs.cli(main, args=[]) is None
+    assert dcargs.cli(main, args="--x None".split(" ")) is None
+    assert dcargs.cli(main, args="--x None 3 2 2".split(" ")) == [(None, 3, (2, 2))]
+    assert dcargs.cli(main, args="--x 2 3 x 2".split(" ")) == [(2, 3, ("x", "2"))]
+    assert dcargs.cli(main, args="--x 2 3 x 2 2 3 1 2".split(" ")) == [
+        (2, 3, ("x", "2")),
+        (2, 3, (1, 2)),
+    ]
+    with pytest.raises(SystemExit):
+        dcargs.cli(main, args=["--help"])