Merge branch 'master' into release/v0.31.0

CHANGES.rst

@@ -9,6 +9,25 @@ Enhancements:
 
 - Added `always_flush` argument to `dispatch()` (issue #145)
 
+Version 0.30.1
+--------------
+
+Bugs fixed:
+
+- Regression: certain special values in argument default value would cause an
+  exception (#204)
+
+Enhancements:
+
+- Improved the tutorial.
+- Added a more informative error message when the reason is likely to be
+  related to the migration from Argh v0.29 to a version with a new argument
+  name mapping policy.
+
+Other changes:
+
+- Added `py.typed` marker file for :pep:`561`.
+
 Version 0.30.0
 --------------
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "flit_core.buildapi"
 
 [project]
 name = "argh"
-version = "0.30.0"
+version = "0.30.1"
 description = "An unobtrusive argparse wrapper with natural syntax"
 readme = "README.rst"
 requires-python = ">=3.8"

src/argh/assembling.py

@@ -16,7 +16,6 @@
 import inspect
 from argparse import OPTIONAL, ZERO_OR_MORE, ArgumentParser
 from collections import OrderedDict
-from dataclasses import asdict
 from enum import Enum
 from typing import Any, Callable, Dict, Iterator, List, Optional, Tuple
 
@@ -315,9 +314,9 @@ def set_default_command(
             raise AssemblingError(f"{function.__name__}: {exc}") from exc
 
     # add the fully formed argument specs to the parser
-    for orig_spec in parser_add_argument_specs:
-        spec = _prepare_parser_add_argument_spec(
-            parser_add_argument_spec=orig_spec, parser_adds_help_arg=parser.add_help
+    for spec in parser_add_argument_specs:
+        _extend_parser_add_argument_spec(
+            spec=spec, parser_adds_help_arg=parser.add_help
         )
 
         try:
@@ -347,12 +346,9 @@ def set_default_command(
     )
 
 
-def _prepare_parser_add_argument_spec(
-    parser_add_argument_spec: ParserAddArgumentSpec, parser_adds_help_arg: bool
-) -> ParserAddArgumentSpec:
-    # deep copy
-    spec = ParserAddArgumentSpec(**asdict(parser_add_argument_spec))
-
+def _extend_parser_add_argument_spec(
+    spec: ParserAddArgumentSpec, parser_adds_help_arg: bool
+) -> None:
     # add types, actions, etc. (e.g. default=3 implies type=int)
     spec.other_add_parser_kwargs.update(
         guess_extra_parser_add_argument_spec_kwargs(spec)
@@ -369,8 +365,6 @@ def _prepare_parser_add_argument_spec(
     if parser_adds_help_arg and "-h" in spec.cli_arg_names:
         spec.cli_arg_names = [name for name in spec.cli_arg_names if name != "-h"]
 
-    return spec
-
 
 def _merge_inferred_and_declared_args(
     inferred_args: List[ParserAddArgumentSpec],
@@ -421,7 +415,10 @@ def _merge_inferred_and_declared_args(
                 kind_declared = kinds[decl_positional]
                 raise AssemblingError(
                     f'argument "{func_arg_name}" declared as {kind_inferred} '
-                    f"(in function signature) and {kind_declared} (via decorator)"
+                    f"(in function signature) and {kind_declared} (via decorator). "
+                    "If you've just migrated from Argh v.0.29, please check "
+                    "the new default NameMappingPolicy. Perhaps you need "
+                    "to replace `func(x=1)` with `func(*, x=1)`?"
                 )
 
             # merge explicit argument declaration into the inferred one

src/argh/py.typed

@@ -0,0 +1 @@
+# Marker file for PEP-561

tests/test_regressions.py

@@ -2,6 +2,9 @@
 Regression tests
 ~~~~~~~~~~~~~~~~
 """
+import sys
+from typing import TextIO
+
 import pytest
 
 import argh
@@ -113,7 +116,9 @@ def func(foo_bar):
         parser.set_default_command(func)
     msg = (
         'func: argument "foo_bar" declared as positional (in function '
-        "signature) and optional (via decorator)"
+        "signature) and optional (via decorator). If you've just migrated "
+        "from Argh v.0.29, please check the new default NameMappingPolicy. "
+        "Perhaps you need to replace `func(x=1)` with `func(*, x=1)`?"
     )
     assert excinfo.exconly().endswith(msg)
 
@@ -150,3 +155,19 @@ def cmd(foo_foo, bar_bar, *, baz_baz=5, bip_bip=9, **kwargs):
     parser.set_default_command(cmd)
     expected = "abc\ndef\n8\n9\n{}\n"
     assert run(parser, "abc def --baz-baz 8").out == expected
+
+
+def test_regression_issue204():
+    """
+    Issue #204: `asdict(ParserAddArgumentSpec)` used `deepcopy` which would
+    lead to "TypeError: cannot pickle..." if e.g. a default value contained an
+    un-pickle-able object.
+
+    We should avoid `deepcopy()` in standard operations.
+    """
+
+    def func(x: TextIO = sys.stdout) -> None:
+        ...
+
+    parser = DebugArghParser()
+    parser.set_default_command(func)