added a test for the show_all command

Author: dantownsend

tests/apps/app/commands/test_show_all.py

@@ -0,0 +1,15 @@
+from unittest import TestCase
+from unittest.mock import call, patch
+
+from piccolo.apps.app.commands.show_all import show_all
+
+
+class TestShowAll(TestCase):
+    @patch("piccolo.apps.app.commands.show_all.print")
+    def test_show_all(self, mocked_print):
+        show_all()
+
+        self.assertEqual(
+            mocked_print.mock_calls,
+            [call("Registered apps:"), call("tests.example_app.piccolo_app")],
+        )