Updates reg.arginfo to make direct use of inspect.signature

.github/workflows/main.yml

@@ -19,13 +19,13 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "pypy3"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "pypy3"]
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: "actions/checkout@v2"
-      - uses: "actions/setup-python@v2"
+      - uses: "actions/checkout@v6"
+      - uses: "actions/setup-python@v6"
         with:
           python-version: "${{ matrix.python-version }}"
       - name: "Install dependencies"
@@ -34,15 +34,16 @@ jobs:
           python -VV
           python -m site
           python -m pip install --upgrade pip setuptools wheel
-          python -m pip install --upgrade virtualenv tox tox-gh-actions          
+          # FIXME: Make tox.ini compatible with newer versions of tox
+          python -m pip install --upgrade virtualenv 'tox<4' tox-gh-actions          
       - name: "Run tox targets for ${{ matrix.python-version }}"
         run: "python -m tox"
 
       - name: "Report to coveralls"
-        # coverage is only created in the py39 environment
+        # coverage is only created in the py314 environment
         # --service=github is a workaround for bug
         # https://github.com/coveralls-clients/coveralls-python/issues/251
-        if: "matrix.python-version == '3.9'"
+        if: "matrix.python-version == '3.14'"
         run: |
           pip install coveralls
           coveralls --service=github

.pre-commit-config.yaml

@@ -1,14 +1,14 @@
 repos:
   - repo: https://github.com/psf/black
-    rev: 20.8b1
+    rev: 26.3.1
     hooks:
       - id: black
   - repo: https://github.com/PyCQA/flake8
-    rev: "3.8.4"
+    rev: "7.3.0"
     hooks:
       - id: flake8
   - repo: https://github.com/asottile/pyupgrade
-    rev: v2.7.4
+    rev: v3.21.2
     hooks:
     - id: pyupgrade
       args: [--py36-plus]

CHANGES.txt

@@ -4,7 +4,19 @@ CHANGES
 0.13 (unreleased)
 =================
 
-- Drop support for Python below 3.6
+- ``reg.arginfo`` is now implemented manually using
+  ``inspect.signature``, instead of relying the deprecated
+  compatibility method in ``inspect``, in order to better
+  support Python 3.14+.
+
+  It is recommended to migrate from ``reg.arginfo`` to pure
+  ``inspect.signature``, since the utility this module provides
+  is now very limited, compared to ``inspect.signature``, since
+  that already properly handles ``self`` parameters.
+
+- Added support for Python 3.10, 3.11, 3.12, 3.13 and 3.14
+
+- Drop support for Python below 3.10
 
 - Use GitHub Actions for CI
 

develop_requirements.txt

@@ -1,7 +1,8 @@
 # development
 -e '.[test,coverage,pep8,docs]'
 pre-commit
-tox >= 2.4.1
+# FIXME: Make tox.ini compatible with newer versions of tox
+tox >= 2.4.1, < 4
 radon
 
 # releaser

reg/arginfo.py

@@ -1,4 +1,18 @@
 import inspect
+import sys
+
+if sys.version_info < (3, 14):
+
+    def get_signature(callable):
+        """A compatibility wrapper for `inspect.signature`."""
+        return inspect.signature(callable)
+
+else:
+    from annotationlib import Format
+
+    def get_signature(callable):
+        """A compatibility wrapper for `inspect.signature`."""
+        return inspect.signature(callable, annotation_format=Format.FORWARDREF)
 
 
 def arginfo(callable):
@@ -10,7 +24,10 @@ def arginfo(callable):
     :func:`inspect.getfullargspec` returns information about the arguments
     of a function. arginfo also works for classes and instances with a
     __call__ defined. Unlike getfullargspec, arginfo treats bound methods
-    like functions, so that the self argument is not reported.
+    like functions, so that the self argument is not reported. Another
+    difference is the handling of decorated functions. This will return
+    the original signature, rather than the signature of the wrapper, if
+    wrapped via :func:`functools.wraps`.
 
     arginfo returns ``None`` if given something that is not callable.
 
@@ -29,22 +46,67 @@ def arginfo(callable):
             return arginfo._cache[callable.__call__]
         except (AttributeError, KeyError):
             pass
-    func, cache_key, remove_self = get_callable_info(callable)
-    if func is None:
-        return None
-    result = inspect.getfullargspec(func)
-    if remove_self:
-        args = result.args[1:]
-        result = inspect.FullArgSpec(
-            args,
-            result.varargs,
-            result.varkw,
-            result.defaults,
-            result.kwonlyargs,
-            result.kwonlydefaults,
-            result.annotations,
-        )
-    arginfo._cache[cache_key] = result
+
+    if inspect.isfunction(callable):
+        cache_key = callable
+    elif inspect.ismethod(callable):
+        cache_key = callable
+    elif inspect.isclass(callable):
+        cache_key = callable
+        if callable.__init__ is WRAPPER_DESCRIPTOR:
+            # Only in this specific case do we replace the callable
+            # into `inspect.signature` with something else, to ensure
+            # we don't get a `ValueError` and instead end up with
+            # an empty signature.
+            callable = fake_empty_init
+    else:
+        # Since arbitrary callable objects may not be hashable
+        # we instead retrieve their call method, which should be
+        try:
+            cache_key = callable.__call__
+        except AttributeError:
+            return None
+
+    signature = get_signature(callable)
+    args = []
+    varargs = None
+    varkw = None
+    defaults = []
+    kwonlyargs = []
+    kwonlydefaults = {}
+    annotations = {}
+    for parameter in signature.parameters.values():
+        if (
+            parameter.kind is parameter.POSITIONAL_OR_KEYWORD
+            or parameter.kind is parameter.POSITIONAL_ONLY
+        ):
+            args.append(parameter.name)
+            if parameter.default is not parameter.empty:
+                defaults.append(parameter.default)
+        elif parameter.kind is parameter.KEYWORD_ONLY:
+            kwonlyargs.append(parameter.name)
+            if parameter.default is not parameter.empty:
+                kwonlydefaults[parameter.name] = parameter.default
+        elif parameter.kind is parameter.VAR_POSITIONAL:
+            varargs = parameter.name
+        elif parameter.kind is parameter.VAR_KEYWORD:
+            varkw = parameter.name
+
+        if parameter.annotation is not parameter.empty:
+            annotations[parameter.name] = parameter.annotation
+
+    if signature.return_annotation is not signature.empty:
+        annotations["return"] = signature.return_annotation
+
+    result = arginfo._cache[cache_key] = inspect.FullArgSpec(
+        args,
+        varargs,
+        varkw,
+        tuple(defaults) if defaults else None,
+        kwonlyargs,
+        kwonlydefaults,
+        annotations,
+    )
     return result
 
 
@@ -58,35 +120,6 @@ def is_cached(callable):
 arginfo.is_cached = is_cached
 
 
-def get_callable_info(callable):
-    """Get information about a callable.
-
-    Returns a tuple of:
-
-    * actual function/method that can be inspected with inspect.getfullargspec.
-
-    * cache key to use to cache results.
-
-    * whether to remove self or not.
-
-    Note that in Python 3, __init__ is not a method, but we still
-    want to remove self from it.
-
-    If not inspectable (None, None, False) is returned.
-    """
-    if inspect.isfunction(callable):
-        return callable, callable, False
-    if inspect.ismethod(callable):
-        return callable, callable, True
-    if inspect.isclass(callable):
-        return get_class_init(callable), callable, True
-    try:
-        callable = getattr(callable, "__call__")
-        return callable, callable, True
-    except AttributeError:
-        return None, None, False
-
-
 def fake_empty_init():
     pass  # pragma: nocoverage
 
@@ -96,13 +129,3 @@ class Dummy:
 
 
 WRAPPER_DESCRIPTOR = Dummy.__init__
-
-
-def get_class_init(class_):
-    func = class_.__init__
-
-    # If this is a new-style class and there is no __init__
-    # defined this is a WRAPPER_DESCRIPTOR.
-    if func is WRAPPER_DESCRIPTOR:
-        return fake_empty_init
-    return func

reg/tests/test_docgen.py

@@ -1,4 +1,5 @@
 import pydoc
+import sys
 from sphinx.application import Sphinx
 from .fixtures.module import Foo, foo
 
@@ -31,42 +32,37 @@ class Foo({builtins}.object)
  |  Data descriptors defined here:
  |
  |  __dict__
- |      dictionary for instance variables (if defined)
+ |      dictionary for instance variables{postamble}
  |
  |  __weakref__
- |      list of weak references to the object (if defined)
+ |      list of weak references to the object{postamble}
 """.format(
-            builtins=object.__module__
+            builtins=object.__module__,
+            postamble=" (if defined)" if sys.version_info < (3, 11) else "",
         )
     )
 
 
 def test_dispatch_method_help(capsys):
     pydoc.help(Foo.bar)
     out, err = capsys.readouterr()
-    assert (
-        rstrip_lines(out)
-        == """\
+    assert rstrip_lines(out) == """\
 Help on function bar in module reg.tests.fixtures.module:
 
 bar(self, obj)
     Return the bar of an object.
 """
-    )
 
 
 def test_dispatch_help(capsys):
     pydoc.help(foo)
     out, err = capsys.readouterr()
-    assert (
-        rstrip_lines(out)
-        == """\
+    assert rstrip_lines(out) == """\
 Help on function foo in module reg.tests.fixtures.module:
 
 foo(obj)
     return the foo of an object.
 """
-    )
 
 
 def test_autodoc(tmpdir):
@@ -80,9 +76,7 @@ def test_autodoc(tmpdir):
     # remove it.
     app = Sphinx(root, root, root + "/build", root, "text", status=None)
     app.build()
-    assert (
-        tmpdir.join("build/contents.txt").read()
-        == """\
+    assert tmpdir.join("build/contents.txt").read() == """\
 Sample module for testing autodoc.
 
 class reg.tests.fixtures.module.Foo
@@ -101,4 +95,3 @@ class reg.tests.fixtures.module.Foo
 
    return the foo of an object.
 """
-    )

setup.py

@@ -23,10 +23,11 @@
         "Intended Audience :: Developers",
         "License :: OSI Approved :: BSD License",
         "Topic :: Software Development :: Libraries :: Python Modules",
-        "Programming Language :: Python :: 3.6",
-        "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: 3.8",
-        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
+        "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: 3.12",
+        "Programming Language :: Python :: 3.13",
+        "Programming Language :: Python :: 3.14",
         "Programming Language :: Python :: Implementation :: PyPy",
         "Development Status :: 5 - Production/Stable",
     ],

tox.ini

@@ -1,12 +1,11 @@
 [tox]
-envlist = py36, py37, py38, py39, pypy3, coverage, pre-commit, docs, perf
+envlist = py310, py311, py312, py313, py314, pypy3, coverage, pre-commit, docs, perf
 skipsdist = True
 skip_missing_interpreters = True
 
 [testenv]
 usedevelop = True
 extras = test
-
 commands = pytest {posargs}
 
 [testenv:coverage]
@@ -34,10 +33,11 @@ commands = python {toxinidir}/tox_perf.py
 
 [gh-actions]
 python =
-    3.6: py36
-    3.7: py37, perf
-    3.8: py38
-    3.9: py39, pre-commit, mypy, coverage
+    3.10: py310, perf
+    3.11: py311
+    3.12: py312
+    3.13: py313
+    3.14: py314, pre-commit, coverage
 
 [flake8]
 max-line-length = 88