Refs #29501 -- Added test for missing dbshell executable.

tests/dbshell/tests.py

@@ -0,0 +1,17 @@
+from unittest import mock
+
+from django.core.management import call_command
+from django.core.management.base import CommandError
+from django.db import connection
+from django.test import SimpleTestCase
+
+
+class DbshellCommandTestCase(SimpleTestCase):
+    def test_command_missing(self):
+        msg = (
+            'You appear not to have the %r program installed or on your path.'
+            % connection.client.executable_name
+        )
+        with self.assertRaisesMessage(CommandError, msg):
+            with mock.patch('subprocess.run', side_effect=FileNotFoundError):
+                call_command('dbshell')