From df397a786a7416851c5fad20988a5777046a2d98 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Mon, 8 Jan 2024 22:09:32 -0500
Subject: [PATCH] Allow Hashable = None in type annotations

---
 .../ruff_linter/resources/test/fixtures/ruff/RUF013_0.py | 8 +++++++-
 crates/ruff_linter/src/rules/ruff/typing.rs              | 9 +++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/crates/ruff_linter/resources/test/fixtures/ruff/RUF013_0.py b/crates/ruff_linter/resources/test/fixtures/ruff/RUF013_0.py
index e4807c9f5ac611..8a3a7b0b434090 100644
--- a/crates/ruff_linter/resources/test/fixtures/ruff/RUF013_0.py
+++ b/crates/ruff_linter/resources/test/fixtures/ruff/RUF013_0.py
@@ -1,5 +1,5 @@
 import typing
-from typing import Annotated, Any, Literal, Optional, Tuple, Union
+from typing import Annotated, Any, Literal, Optional, Tuple, Union, Hashable
 
 
 def f(arg: int):
@@ -257,3 +257,9 @@ def f(arg: "Text" = None):
 
 def f(arg: MaybeInt = None):
     pass
+
+
+# Hashable
+
+def f(arg: Hashable = None):  # OK
+    pass
diff --git a/crates/ruff_linter/src/rules/ruff/typing.rs b/crates/ruff_linter/src/rules/ruff/typing.rs
index 76f825da8f18a0..1c176ca7e4d620 100644
--- a/crates/ruff_linter/src/rules/ruff/typing.rs
+++ b/crates/ruff_linter/src/rules/ruff/typing.rs
@@ -57,6 +57,9 @@ enum TypingTarget<'a> {
     /// A `typing.Annotated` type e.g., `Annotated[int, ...]`.
     Annotated(&'a Expr),
 
+    /// The `typing.Hashable` type.
+    Hashable,
+
     /// Special type used to represent an unknown type (and not a typing target)
     /// which could be a type alias.
     Unknown,
@@ -121,6 +124,10 @@ impl<'a> TypingTarget<'a> {
                         Some(TypingTarget::Any)
                     } else if matches!(call_path.as_slice(), ["" | "builtins", "object"]) {
                         Some(TypingTarget::Object)
+                    } else if semantic.match_typing_call_path(&call_path, "Hashable")
+                        || matches!(call_path.as_slice(), ["collections", "abc", "Hashable"])
+                    {
+                        Some(TypingTarget::Hashable)
                     } else if !is_known_type(&call_path, minor_version) {
                         // If it's not a known type, we assume it's `Any`.
                         Some(TypingTarget::Unknown)
@@ -142,6 +149,7 @@ impl<'a> TypingTarget<'a> {
         match self {
             TypingTarget::None
             | TypingTarget::Optional(_)
+            | TypingTarget::Hashable
             | TypingTarget::Any
             | TypingTarget::Object
             | TypingTarget::Unknown => true,
@@ -191,6 +199,7 @@ impl<'a> TypingTarget<'a> {
             // `Literal` cannot contain `Any` as it's a dynamic value.
             TypingTarget::Literal(_)
             | TypingTarget::None
+            | TypingTarget::Hashable
             | TypingTarget::Object
             | TypingTarget::Known
             | TypingTarget::Unknown => false,