From 6076bff66259e3f1fdb8f3e305fb4bc7452345ce Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Wed, 18 Nov 2020 01:22:55 +0900
Subject: [PATCH] refactor: Add sphinx.util.typing.get_type_hints()

Add a simple wrapper of `typing.get_type_hints()` that does not raise
an error on runtime.
---
 sphinx/ext/autodoc/__init__.py | 36 ++++------------------------------
 sphinx/util/typing.py          | 23 ++++++++++++++++++++++
 2 files changed, 27 insertions(+), 32 deletions(-)

diff --git a/sphinx/ext/autodoc/__init__.py b/sphinx/ext/autodoc/__init__.py
index a79e540eb..665927268 100644
--- a/sphinx/ext/autodoc/__init__.py
+++ b/sphinx/ext/autodoc/__init__.py
@@ -16,7 +16,7 @@ import warnings
 from inspect import Parameter, Signature
 from types import ModuleType
 from typing import (Any, Callable, Dict, Iterator, List, Optional, Sequence, Set, Tuple, Type,
-                    TypeVar, Union, get_type_hints)
+                    TypeVar, Union)
 
 from docutils.statemachine import StringList
 
@@ -33,7 +33,7 @@ from sphinx.util import inspect, logging
 from sphinx.util.docstrings import extract_metadata, prepare_docstring
 from sphinx.util.inspect import (evaluate_signature, getdoc, object_description, safe_getattr,
                                  stringify_signature)
-from sphinx.util.typing import restify
+from sphinx.util.typing import get_type_hints, restify
 from sphinx.util.typing import stringify as stringify_typehint
 
 if False:
@@ -1701,21 +1701,7 @@ class DataDocumenter(ModuleLevelDocumenter):
         sourcename = self.get_sourcename()
         if not self.options.annotation:
             # obtain annotation for this data
-            try:
-                annotations = get_type_hints(self.parent, None,
-                                             self.config.autodoc_type_aliases)
-            except NameError:
-                # Failed to evaluate ForwardRef (maybe TYPE_CHECKING)
-                annotations = safe_getattr(self.parent, '__annotations__', {})
-            except TypeError:
-                annotations = {}
-            except KeyError:
-                # a broken class found (refs: https://github.com/sphinx-doc/sphinx/issues/8084)
-                annotations = {}
-            except AttributeError:
-                # AttributeError is raised on 3.5.2 (fixed by 3.5.3)
-                annotations = {}
-
+            annotations = get_type_hints(self.parent, None, self.config.autodoc_type_aliases)
             if self.objpath[-1] in annotations:
                 objrepr = stringify_typehint(annotations.get(self.objpath[-1]))
                 self.add_line('   :type: ' + objrepr, sourcename)
@@ -2093,21 +2079,7 @@ class AttributeDocumenter(DocstringStripSignatureMixin, ClassLevelDocumenter):
         sourcename = self.get_sourcename()
         if not self.options.annotation:
             # obtain type annotation for this attribute
-            try:
-                annotations = get_type_hints(self.parent, None,
-                                             self.config.autodoc_type_aliases)
-            except NameError:
-                # Failed to evaluate ForwardRef (maybe TYPE_CHECKING)
-                annotations = safe_getattr(self.parent, '__annotations__', {})
-            except TypeError:
-                annotations = {}
-            except KeyError:
-                # a broken class found (refs: https://github.com/sphinx-doc/sphinx/issues/8084)
-                annotations = {}
-            except AttributeError:
-                # AttributeError is raised on 3.5.2 (fixed by 3.5.3)
-                annotations = {}
-
+            annotations = get_type_hints(self.parent, None, self.config.autodoc_type_aliases)
             if self.objpath[-1] in annotations:
                 objrepr = stringify_typehint(annotations.get(self.objpath[-1]))
                 self.add_line('   :type: ' + objrepr, sourcename)
diff --git a/sphinx/util/typing.py b/sphinx/util/typing.py
index 28f9c5e38..18649433b 100644
--- a/sphinx/util/typing.py
+++ b/sphinx/util/typing.py
@@ -57,6 +57,29 @@ TitleGetter = Callable[[nodes.Node], str]
 Inventory = Dict[str, Dict[str, Tuple[str, str, str, str]]]
 
 
+def get_type_hints(obj: Any, globalns: Dict = None, localns: Dict = None) -> Dict[str, Any]:
+    """Return a dictionary containing type hints for a function, method, module or class object.
+
+    This is a simple wrapper of `typing.get_type_hints()` that does not raise an error on
+    runtime.
+    """
+    from sphinx.util.inspect import safe_getattr  # lazy loading
+
+    try:
+        return typing.get_type_hints(obj, None, localns)
+    except NameError:
+        # Failed to evaluate ForwardRef (maybe TYPE_CHECKING)
+        return safe_getattr(obj, '__annotations__', {})
+    except TypeError:
+        return {}
+    except KeyError:
+        # a broken class found (refs: https://github.com/sphinx-doc/sphinx/issues/8084)
+        return {}
+    except AttributeError:
+        # AttributeError is raised on 3.5.2 (fixed by 3.5.3)
+        return {}
+
+
 def is_system_TypeVar(typ: Any) -> bool:
     """Check *typ* is system defined TypeVar."""
     modname = getattr(typ, '__module__', '')