From 5d7be279c9eb2b3a723809ff7b0fae5d38df8eb2 Mon Sep 17 00:00:00 2001
From: Sanjay Santhanam <51058514+Sanjays2402@users.noreply.github.com>
Date: Sat, 25 Jul 2026 14:25:45 -0700
Subject: [PATCH] fix(cli): point at --help when arguments are invalid

Running `sqlformat` with no arguments (or any invalid argument
combination handled by argparse) printed only the usage line and the
error, giving no hint that `--help` exists.

argparse's default `error()` is overridden in a small ArgumentParser
subclass so every argument error is followed by
"Try 'sqlformat --help' for more information." Exit code stays 2.

Closes #840
---
 sqlparse/cli.py   | 10 +++++++++-
 tests/test_cli.py |  9 +++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/sqlparse/cli.py b/sqlparse/cli.py
index 03ee86e3..caaf647a 100644
--- a/sqlparse/cli.py
+++ b/sqlparse/cli.py
@@ -27,10 +27,18 @@
 
 # TODO: Add CLI Tests
 # TODO: Simplify formatter by using argparse `type` arguments
+class _ArgumentParser(argparse.ArgumentParser):
+    """ArgumentParser that points at --help when arguments are invalid."""
+
+    def error(self, message):
+        self.exit(2, f'{self.format_usage()}{self.prog}: error: {message}\n'
+                     f"Try '{self.prog} --help' for more information.\n")
+
+
 def create_parser():
     _CASE_CHOICES = ['upper', 'lower', 'capitalize']
 
-    parser = argparse.ArgumentParser(
+    parser = _ArgumentParser(
         prog='sqlformat',
         description='Format FILE according to OPTIONS. Use "-" as FILE '
                     'to read from stdin.',
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 4aec44d3..a01f0e7b 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -204,3 +204,12 @@ def test_cli_error_handling_continues(tmpdir, capsys):
     assert "select * from baz" in file3.read()
     _, err = capsys.readouterr()
     assert "Failed to read" in err
+
+
+def test_cli_argument_error_mentions_help(capsys):
+    """Argument errors should point the user at --help."""
+    with pytest.raises(SystemExit) as exinfo:
+        sqlparse.cli.main([])
+    assert exinfo.value.code == 2
+    _, err = capsys.readouterr()
+    assert "Try 'sqlformat --help' for more information." in err