fix: kw_only dataclass inheritance mis-ordering.

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## 0.32
 
+### 0.32.1
+
+- fix: kw_only dataclass inheritance mis-ordering.
+
 ### 0.32.0
 - feat: Add `epilog=` field on commands for text which should go after the argument help.
 - refactor: All root objects (Command/Arg/Subcommand) to have "Final" variants which represent their post-normalization shape.

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "cappa"
-version = "0.32.0"
+version = "0.32.1"
 description = "Declarative CLI argument parser."
 
 urls = { repository = "https://github.com/dancardin/cappa" }

src/cappa/command.py

@@ -217,7 +217,9 @@ def collect(
                     raw_subcommands.append((arg, None, None))
 
         else:
-            for field, param_view in zip(fields, function_view.parameters):
+            param_by_name = {p.name: p for p in function_view.parameters}
+            for field in fields:
+                param_view = param_by_name[field.name]
                 arg_help = help_text.args.get(param_view.name)
 
                 maybe_subcommand = Subcommand.detect(

tests/test_base.py

@@ -5,7 +5,7 @@
 
 import cappa
 from cappa.command import Command
-from tests.utils import Backend, backends
+from tests.utils import Backend, backends, require_dataclass_kw_only
 
 
 @backends
@@ -165,6 +165,27 @@ class Example: ...
     assert result == Example()
 
 
+@require_dataclass_kw_only
+@backends
+def test_kw_only_base_class_field_ordering(backend: Backend):
+    kwargs = {"kw_only": True}
+
+    @dataclass(**kwargs)
+    class Base:
+        name: str = "hello"
+
+    @dataclass
+    class Child(Base):
+        number: int = 0
+
+    result = cappa.parse(
+        cappa.Command(Child, default_long=True),
+        argv=["--name", "world"],
+        backend=backend,
+    )
+    assert result == Child(number=0, name="world")
+
+
 @backends
 def test_collect_skips_non_init_fields(backend: Backend):
     @dataclass

tests/utils.py

@@ -2,6 +2,7 @@
 
 import contextlib
 import os
+import sys
 from dataclasses import dataclass
 from typing import Any, Union
 from unittest.mock import patch
@@ -23,9 +24,14 @@
     "invoke",
     "invoke_async",
     "parse",
+    "require_dataclass_kw_only",
     "runner",
 ]
 
+require_dataclass_kw_only = pytest.mark.skipif(
+    sys.version_info < (3, 10), reason="kw_only requires Python 3.10+"
+)
+
 backends = pytest.mark.parametrize(
     "backend",
     [