fix Parser do not examine PEP 526 __annotations__

Signed-off-by: Zhiyuan Chen <[email protected]>

chanfig/parser.py

@@ -22,11 +22,14 @@
 from ast import literal_eval
 from collections.abc import Sequence
 from contextlib import suppress
-from typing import TYPE_CHECKING, Any
+from dataclasses import Field
+from inspect import isclass
+from types import NoneType, UnionType
+from typing import TYPE_CHECKING, Any, _UnionGenericAlias, get_args  # type: ignore[attr-defined]
 from warnings import warn
 
 from .nested_dict import NestedDict
-from .utils import Null, parse_bool
+from .utils import Null, get_annotations, parse_bool
 from .variable import Variable
 
 if TYPE_CHECKING:
@@ -277,23 +280,38 @@ def parse_args(  # type: ignore[override]
                     parsed[key] = value
         return parsed
 
-    def add_config_arguments(self, config):
+    def add_config_arguments(self, config: Config):
+        for key, dtype in get_annotations(config).items():
+            self.add_config_argument(key, dtype=dtype)
         for key, value in config.all_items():
+            self.add_config_argument(key, value)
+
+    def add_config_argument(self, key, value: Any | None = None, dtype: type | None = None):
+        if dtype is None:
             if isinstance(value, Variable):
                 dtype = value._type or value.dtype  # pylint: disable=W0212
+            elif isinstance(value, Field):
+                dtype = value.type
             elif value is not None:
                 dtype = type(value)
-            else:
-                dtype = None
-            name = "--" + key
-            if name not in self:
-                help = value._help if isinstance(value, Variable) else None  # pylint: disable=W0212,W0622
-                if isinstance(value, (list, tuple, dict, set)):
-                    self.add_argument(name, type=dtype, nargs="+", help=help, dest=key)
-                elif isinstance(value, bool):
-                    self.add_argument(name, type=parse_bool, help=help, dest=key)
-                else:
-                    self.add_argument(name, type=dtype, help=help, dest=key)
+        if isinstance(dtype, (UnionType, _UnionGenericAlias)):
+            args = get_args(dtype)
+            if len(args) == 2 and NoneType in args:
+                dtype = args[0] if args[0] is not NoneType else args[1]
+        name = "--" + key
+        if name not in self:
+            help = None  # pylint: disable=W0622
+            if isinstance(value, Variable):
+                help = value._help  # pylint: disable=W0212
+            elif isinstance(value, Field):
+                help = value.metadata.get("help")
+            if dtype is None or not isclass(dtype):
+                return self.add_argument(name, help=help, dest=key)
+            if issubclass(dtype, (list, tuple, dict, set)):
+                return self.add_argument(name, type=dtype, nargs="+", help=help, dest=key)
+            if issubclass(dtype, bool):
+                return self.add_argument(name, type=parse_bool, help=help, dest=key)
+            return self.add_argument(name, type=dtype, help=help, dest=key)
 
     def merge_default_config(self, parsed, default_config: str, no_default_config_action: str = "raise") -> NestedDict:
         message = f"default_config is set to {default_config}, but not found in args."

tests/test_parser.py

@@ -0,0 +1,88 @@
+# CHANfiG, Easier Configuration.
+# Copyright (c) 2022-Present, CHANfiG Contributors
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the following licenses:
+# - The Unlicense
+# - GNU Affero General Public License v3.0 or later
+# - GNU General Public License v2.0 or later
+# - BSD 4-Clause "Original" or "Old" License
+# - MIT License
+# - Apache License 2.0
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the LICENSE file for more details.
+
+from __future__ import annotations
+
+from typing import List, Optional
+
+from chanfig import Config
+
+
+class TestConfig(Config):
+    __test__ = False
+
+    t: bool
+    true: bool
+    y: bool
+    yes: Optional[bool]
+    f: bool
+    false: bool
+    n: bool
+    no: bool | None
+    not_recognized: List[bool]
+
+
+class Test:
+
+    def test_parse_bool(self):
+        config = TestConfig()
+        config.parse(
+            [
+                "--t",
+                "t",
+                "--true",
+                "true",
+                "--y",
+                "y",
+                "--yes",
+                "yes",
+                "--f",
+                "f",
+                "--false",
+                "false",
+                "--n",
+                "n",
+                "--no",
+                "no",
+            ]
+        )
+        assert config.t and config.true and config.y and config.yes
+        assert not config.f and not config.false and not config.n and not config.no
+
+        config = TestConfig()
+        config.parse(
+            [
+                "--t",
+                "T",
+                "--true",
+                "True",
+                "--y",
+                "Y",
+                "--yes",
+                "Yes",
+                "--f",
+                "F",
+                "--false",
+                "False",
+                "--n",
+                "N",
+                "--no",
+                "No",
+            ]
+        )
+        assert config.t and config.true and config.y and config.yes
+        assert not config.f and not config.false and not config.n and not config.no