Better keyword_casing=auto heuristic.

Consider both the first and last letter of the user's text when
choosing case for completion candidates when keyword_casing=auto.

The issue is that when the last character typed is non-alphabetic
such as underscore, then islower() is False.  Better to check both the
first and last character of the user's text.  If either of them is
lowercase then we complete with lowercase.

Author: rolandwalker

changelog.md

@@ -1,3 +1,11 @@
+TBD
+==============
+
+Bug Fixes
+--------
+* Better respect case when `keyword_casing` is `auto`.
+
+
 1.47.0 (2026/01/24)
 ==============
 

mycli/sqlcompleter.py

@@ -1027,7 +1027,7 @@ def find_matches(
                     completions.append(item)
 
         if casing == "auto":
-            casing = "lower" if last and last[-1].islower() else "upper"
+            casing = "lower" if last and (last[0].islower() or last[-1].islower()) else "upper"
 
         def apply_case(kw: str) -> str:
             if casing == "upper":

test/test_smart_completion_public_schema_only.py

@@ -544,3 +544,15 @@ def test_file_name_completion(completer, complete_event, text, expected):
     result = list(completer.get_completions(Document(text=text, cursor_position=position), complete_event))
     expected = [Completion(txt, pos) for txt, pos in expected]
     assert result == expected
+
+
+def test_auto_case_heuristic(completer, complete_event):
+    text = "select jon_"
+    position = len("select jon_")
+    result = list(completer.get_completions(Document(text=text, cursor_position=position), complete_event))
+    assert [x.text for x in result] == [
+        'json_table',
+        'json_value',
+        'join',
+        'json',
+    ]