From 333e7a447edfcb3092032ac801116e1eec193e44 Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Sat, 21 Nov 2020 01:30:17 +0900
Subject: [PATCH] Fix #8452: autodoc_type_aliases doesn't work with
 autodoc_typehints

---
 CHANGES                           |  2 ++
 sphinx/ext/autodoc/typehints.py   |  2 +-
 tests/test_ext_autodoc_configs.py | 22 ++++++++++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index d9f1e06b2..f44b28e19 100644
--- a/CHANGES
+++ b/CHANGES
@@ -47,6 +47,8 @@ Bugs fixed
   type annotated variables
 * #8443: autodoc: autoattribute directive can't create document for PEP-526
   based uninitalized variables
+* #8452: autodoc: autodoc_type_aliases doesn't work when autodoc_typehints is
+  set to "description"
 * #8419: html search: Do not load ``language_data.js`` in non-search pages
 * #8454: graphviz: The layout option for graph and digraph directives don't work
 
diff --git a/sphinx/ext/autodoc/typehints.py b/sphinx/ext/autodoc/typehints.py
index 70cbc3ba1..e6451b52c 100644
--- a/sphinx/ext/autodoc/typehints.py
+++ b/sphinx/ext/autodoc/typehints.py
@@ -27,7 +27,7 @@ def record_typehints(app: Sphinx, objtype: str, name: str, obj: Any,
         if callable(obj):
             annotations = app.env.temp_data.setdefault('annotations', {})
             annotation = annotations.setdefault(name, OrderedDict())
-            sig = inspect.signature(obj)
+            sig = inspect.signature(obj, type_aliases=app.config.autodoc_type_aliases)
             for param in sig.parameters.values():
                 if param.annotation is not param.empty:
                     annotation[param.name] = typing.stringify(param.annotation)
diff --git a/tests/test_ext_autodoc_configs.py b/tests/test_ext_autodoc_configs.py
index 4dff7c3db..ca7968bba 100644
--- a/tests/test_ext_autodoc_configs.py
+++ b/tests/test_ext_autodoc_configs.py
@@ -777,6 +777,28 @@ def test_autodoc_type_aliases(app):
     ]
 
 
+@pytest.mark.skipif(sys.version_info < (3, 7), reason='python 3.7+ is required.')
+@pytest.mark.sphinx('text', testroot='ext-autodoc',
+                    srcdir='autodoc_typehints_description_and_type_aliases',
+                    confoverrides={'autodoc_typehints': "description",
+                                   'autodoc_type_aliases': {'myint': 'myint'}})
+def test_autodoc_typehints_description_and_type_aliases(app):
+    (app.srcdir / 'annotations.rst').write_text('.. autofunction:: target.annotations.sum')
+    app.build()
+    context = (app.outdir / 'annotations.txt').read_text()
+    assert ('target.annotations.sum(x, y)\n'
+            '\n'
+            '   docstring\n'
+            '\n'
+            '   Parameters:\n'
+            '      * **x** (*myint*) --\n'
+            '\n'
+            '      * **y** (*myint*) --\n'
+            '\n'
+            '   Return type:\n'
+            '      myint\n' == context)
+
+
 @pytest.mark.sphinx('html', testroot='ext-autodoc')
 def test_autodoc_default_options(app):
     # no settings