Ticket #18387: 18387-1.diff

django/core/management/base.py

@@ -266 +266 @@
                 if self.output_transaction:
                     self.stdout.write('\n' + self.style.SQL_KEYWORD("COMMIT;"))
         except CommandError as e:
+            if options.get('raise_on_error', False):
+                raise
             if show_traceback:
-                traceback.print_exc()
+                self.stderr.write(traceback.format_exc())
             else:
                 self.stderr.write('Error: %s' % e)
             sys.exit(1)

docs/ref/django-admin.txt

@@ -1468 +1468 @@
 ``**options``
   named options accepted on the command-line.
 
+.. versionadded:: 1.5
+
+If you pass ``raise_on_error=True`` as keyword argument to ``call_command``,
+the command will not call ``sys.exit(1)`` when a ``CommandError`` is raised, but
+will simply let ``CommandError`` propagate. This allows you to catch the
+exception, for example when you test a command.
+
 Examples::
 
       from django.core import management
+      from django.core.management.base import CommandError
+
       management.call_command('flush', verbosity=0, interactive=False)
       management.call_command('loaddata', 'test_data', verbosity=0)
+      try:
+          management.call_command('flush', interactive=False, raise_on_error=True)
+      except CommandError:
+          ...

tests/modeltests/user_commands/management/commands/dance.py

@@ -1 +1 @@
 from optparse import make_option
 
-from django.core.management.base import BaseCommand
+from django.core.management.base import BaseCommand, CommandError
 
 
 class Command(BaseCommand):
@@ -15 +15 @@
 
     def handle(self, *args, **options):
         example = options["example"]
+        if example == "raise":
+            raise CommandError()
         self.stdout.write("I don't feel like dancing %s." % options["style"])

tests/modeltests/user_commands/tests.py

@@ -26 +26 @@
             self.assertEqual(translation.get_language(), 'fr')
 
     def test_explode(self):
+        """ Test that an unknown command raises CommandError """
         self.assertRaises(CommandError, management.call_command, ('explode',))
+
+    def test_raiseonerror_arg(self):
+        """ Test that CommandError with call_command(raise_on_error=True) does
+            not produce a SystemExit exception.
+        """
+        with self.assertRaises(CommandError):
+            management.call_command('dance', example="raise", raise_on_error=True)