gh-133390: Extend completion for .commands in sqlite3

Lib/sqlite3/__main__.py

@@ -60,6 +60,7 @@ def runsource(self, source, filename="<input>", symbol="single"):
 
         if not source or source.isspace():
             return False
+        # Remember to update CLI_COMMANDS in _completer.py
         if source[0] == ".":
             match source[1:].strip():
                 case "version":

Lib/sqlite3/_completer.py

@@ -5,15 +5,20 @@
 except ImportError:
     SQLITE_KEYWORDS = ()
 
+CLI_COMMANDS = ('.quit', '.help', '.version')
+
 _completion_matches = []
 
 
 def _complete(text, state):
     global _completion_matches
 
     if state == 0:
-        text_upper = text.upper()
-        _completion_matches = [c for c in SQLITE_KEYWORDS if c.startswith(text_upper)]
+        if text.startswith('.'):
+            _completion_matches = [c for c in CLI_COMMANDS if c.startswith(text)]
+        else:
+            text_upper = text.upper()
+            _completion_matches = [c for c in SQLITE_KEYWORDS if c.startswith(text_upper)]
     try:
         return _completion_matches[state] + " "
     except IndexError:

Lib/test/test_sqlite3/test_cli.py

@@ -249,6 +249,11 @@ def test_complete_sql_keywords(self):
         self.assertIn(b"SELECT", output)
         self.assertIn(b"(1,)", output)
 
+        # .commands are completed without changing case
+        input_ = b".ver\t\n.quit\n"
+        output = self.write_input(input_)
+        self.assertIn(b".version", output)
+
     @unittest.skipIf(sys.platform.startswith("freebsd"),
                     "Two actual tabs are inserted when there are no matching"
                     " completions in the pseudo-terminal opened by run_pty()"