fix: fix data[key] edge case such as an empty string

libs/core/langchain_core/utils/env.py

@@ -45,10 +45,10 @@ def get_from_dict_or_env(
     """
     if isinstance(key, (list, tuple)):
         for k in key:
-            if value := data.get(k):
-                return value
+            if k in data and data[k] is not None:
+                return data[k]
 
-    if isinstance(key, str) and key in data and data[key]:
+    if isinstance(key, str) and key in data and data[key] is not None:
         return data[key]
 
     key_for_err = key[0] if isinstance(key, (list, tuple)) else key

libs/core/tests/unit_tests/utils/test_env.py

@@ -67,3 +67,31 @@ def test_get_from_dict_or_env() -> None:
             )
             is None
         )
+
+
+def test_get_from_dict_or_env_empty_string() -> None:
+    """Test that empty strings are returned consistently for list and string keys."""
+    data = {"key": "", "other": "value"}
+
+    # Test single string key with empty string value
+    assert get_from_dict_or_env(data, "key", "ENV_KEY", default="default") == ""
+
+    # Test list of keys with empty string value (should behave the same)
+    assert get_from_dict_or_env(data, ["key"], "ENV_KEY", default="default") == ""
+
+    # Test list of keys where first key has empty string
+    result = get_from_dict_or_env(data, ["key", "other"], "ENV_KEY", default="default")
+    assert result == ""
+
+
+def test_get_from_dict_or_env_none_value() -> None:
+    """Test that None values are skipped and default is used."""
+    data = {"key": None, "other": "value"}
+
+    # Test single string key with None value - should use default
+    result = get_from_dict_or_env(data, "key", "ENV_KEY", default="default")
+    assert result == "default"
+
+    # Test list of keys with None value - should skip to next key
+    result = get_from_dict_or_env(data, ["key", "other"], "ENV_KEY", default="default")
+    assert result == "value"