From 5929a5e550f8747a296c801fb1979fd59e1fa3db Mon Sep 17 00:00:00 2001
From: dangotbanned <125183946+dangotbanned@users.noreply.github.com>
Date: Fri, 26 Jul 2024 17:08:24 +0100
Subject: [PATCH] fix: Support already parsed shorthand in `FieldChannelMixin`

Ensures the same output from
```py
alt.Y("count()")
alt.Y(alt.agg.count())
```
---
 altair/vegalite/v5/schema/channels.py | 2 +-
 tools/generate_schema_wrapper.py      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/altair/vegalite/v5/schema/channels.py b/altair/vegalite/v5/schema/channels.py
index 530af95ee..0d14bc3ac 100644
--- a/altair/vegalite/v5/schema/channels.py
+++ b/altair/vegalite/v5/schema/channels.py
@@ -169,7 +169,7 @@ def to_dict(
 
         if shorthand is Undefined:
             parsed = {}
-        elif isinstance(shorthand, str):
+        elif isinstance(shorthand, (str, dict)):
             parsed = parse_shorthand(shorthand, data=context.get("data", None))
             type_required = "type" in self._kwds  # type: ignore[attr-defined]
             type_in_shorthand = "type" in parsed
diff --git a/tools/generate_schema_wrapper.py b/tools/generate_schema_wrapper.py
index 094cd66cc..27bddb525 100644
--- a/tools/generate_schema_wrapper.py
+++ b/tools/generate_schema_wrapper.py
@@ -99,7 +99,7 @@ def to_dict(
 
         if shorthand is Undefined:
             parsed = {}
-        elif isinstance(shorthand, str):
+        elif isinstance(shorthand, (str, dict)):
             parsed = parse_shorthand(shorthand, data=context.get("data", None))
             type_required = "type" in self._kwds  # type: ignore[attr-defined]
             type_in_shorthand = "type" in parsed