From ae80e988edf362ce99a880063639e4cd74bc44bb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timoth=C3=A9e=20Mazzucotelli?= <pawamoy@pm.me>
Date: Tue, 8 Dec 2020 19:08:42 +0100
Subject: [PATCH] fix: Fix attribute parser for Python 3.9

It seems `ast` has changed in Python 3.9.
Some objects who previously had a `value` attribute
don't have it anymore.

Issue #73: https://github.com/pawamoy/pytkdocs/issues/73
Issue #75: https://github.com/pawamoy/pytkdocs/issues/75
---
 src/pytkdocs/parsers/attributes.py     |  7 ++++++-
 tests/fixtures/parsing/annotations.py  | 10 ++++++++++
 tests/test_parsers/test_annotations.py | 20 ++++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 tests/fixtures/parsing/annotations.py
 create mode 100644 tests/test_parsers/test_annotations.py

diff --git a/src/pytkdocs/parsers/attributes.py b/src/pytkdocs/parsers/attributes.py
index ae3146b..065bcbb 100644
--- a/src/pytkdocs/parsers/attributes.py
+++ b/src/pytkdocs/parsers/attributes.py
@@ -16,7 +16,12 @@ def node_to_annotation(node) -> Union[str, object]:
         elif isinstance(node.annotation, (ast.Constant, ast.Str)):
             return node.annotation.s
         elif isinstance(node.annotation, ast.Subscript):
-            return f"{node.annotation.value.id}[{node_to_annotation(node.annotation.slice.value)}]"  # type: ignore
+            value_id = node.annotation.value.id  # type: ignore
+            if hasattr(node.annotation.slice, "value"):
+                value = node.annotation.slice.value  # type: ignore
+            else:
+                value = node.annotation.slice
+            return f"{value_id}[{node_to_annotation(value)}]"
         else:
             return inspect.Signature.empty
     elif isinstance(node, ast.Subscript):
diff --git a/tests/fixtures/parsing/annotations.py b/tests/fixtures/parsing/annotations.py
new file mode 100644
index 0000000..0ee8899
--- /dev/null
+++ b/tests/fixtures/parsing/annotations.py
@@ -0,0 +1,10 @@
+from typing import Any, Dict, List
+
+
+class C:
+    def __init__(self):
+        # https://github.com/pawamoy/pytkdocs/issues/73
+        self.dict_annotation: Dict[str, Any] = {}
+
+        # https://github.com/pawamoy/pytkdocs/issues/75
+        self.list_annotation: List[str] = []
diff --git a/tests/test_parsers/test_annotations.py b/tests/test_parsers/test_annotations.py
new file mode 100644
index 0000000..6ce2adf
--- /dev/null
+++ b/tests/test_parsers/test_annotations.py
@@ -0,0 +1,20 @@
+"""Tests for [the `parsers.attributes` module][pytkdocs.parsers.attributes] on annotations."""
+
+
+from tests.fixtures.parsing import annotations
+
+from pytkdocs.parsers.attributes import get_instance_attributes
+
+
+class TestAnnotations:
+    def setup(self):
+        """Setup reusable attributes."""
+        self.attributes = get_instance_attributes(annotations.C.__init__)
+
+    def test_parse_dict_annotation(self):
+        assert "dict_annotation" in self.attributes
+        assert self.attributes["dict_annotation"]["annotation"] == "Dict[str, Any]"
+
+    def test_parse_list_annotation(self):
+        assert "list_annotation" in self.attributes
+        assert self.attributes["list_annotation"]["annotation"] == "List[str]"