From bbd21b2267e7bedca34edde369bbb8b8514504fe Mon Sep 17 00:00:00 2001
From: Junhyuk Lee <xodn348@users.noreply.github.com>
Date: Mon, 25 May 2026 00:21:06 -0500
Subject: [PATCH] fix(parse): add parentheses for operator precedence in
 minItems check

The condition on line 149 of _transform.py evaluated as:
  (min_items is not None and min_items == 0) or (min_items == 1)
instead of the intended:
  min_items is not None and (min_items == 0 or min_items == 1)

While both produce the same result for all practical inputs,
the explicit parentheses clarify intent and prevent future
misreadings. Adds test coverage for minItems 0 and 1 cases.
---
 src/anthropic/lib/_parse/_transform.py |  2 +-
 tests/lib/_parse/test_transform.py     | 32 ++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/anthropic/lib/_parse/_transform.py b/src/anthropic/lib/_parse/_transform.py
index 755ad280d..60353360d 100644
--- a/src/anthropic/lib/_parse/_transform.py
+++ b/src/anthropic/lib/_parse/_transform.py
@@ -146,7 +146,7 @@ def transform_schema(
             strict_schema["items"] = transform_schema(items)
 
         min_items = json_schema.pop("minItems", None)
-        if min_items is not None and min_items == 0 or min_items == 1:
+        if min_items is not None and (min_items == 0 or min_items == 1):
             strict_schema["minItems"] = min_items
         elif min_items is not None:
             # add it back so its treated as an extra property and appended to the description
diff --git a/tests/lib/_parse/test_transform.py b/tests/lib/_parse/test_transform.py
index 443ca99c9..b1eeb5ffd 100644
--- a/tests/lib/_parse/test_transform.py
+++ b/tests/lib/_parse/test_transform.py
@@ -117,6 +117,38 @@ def test_array_schema():
     )
 
 
+def test_array_schema_min_items_zero():
+    schema = {
+        "type": "array",
+        "items": {"type": "string"},
+        "minItems": 0,
+    }
+    result = transform_schema(schema)
+    assert result == snapshot(
+        {
+            "type": "array",
+            "items": {"type": "string"},
+            "minItems": 0,
+        }
+    )
+
+
+def test_array_schema_min_items_one():
+    schema = {
+        "type": "array",
+        "items": {"type": "string"},
+        "minItems": 1,
+    }
+    result = transform_schema(schema)
+    assert result == snapshot(
+        {
+            "type": "array",
+            "items": {"type": "string"},
+            "minItems": 1,
+        }
+    )
+
+
 def test_string_schema_with_format_and_default():
     schema = {
         "type": "string",