Add function to get a list of all settings in a module

HISTORY

@@ -9,6 +9,8 @@ Features
 - Fully implement split logging configuration. Settings now contains `LOG_HANDLERS`
   and `LOG_LOGGERS` that are merged into the logging configuration before it is
   applied.
+- Add a function `settings_in_module` in the testing package to fetch a list of
+  setting names from a settings module.
 
 
 4.15.1

src/pyapp/testing/__init__.py

@@ -1,4 +1,26 @@
 """Helper methods for testing.
 
- Includes a plugin for Pytest.
- """
+Includes a plugin for Pytest.
+"""
+
+from types import ModuleType
+
+from ..conf.loaders import settings_iterator
+
+
+def settings_in_module(
+    *modules: ModuleType,
+    exclude: list[str] = ("INCLUDE",),
+):
+    """Generate a list of settings defined in a module (or modules).
+
+    Used for ensuring that a second settings module only contains specified settings.
+    """
+    settings = set()
+
+    for mod in modules:
+        settings.update(
+            name for name, _ in settings_iterator(mod) if name not in exclude
+        )
+
+    return settings

tests/unit/testing/test_.py

@@ -0,0 +1,17 @@
+from pyapp import testing
+
+
+def test_settings_in_module():
+    from pyapp.conf import base_settings
+
+    actual = testing.settings_in_module(base_settings)
+
+    assert actual == {
+        "DEBUG",
+        "LOG_LOGGERS",
+        "LOG_HANDLERS",
+        "LOGGING",
+        "CHECK_LOCATIONS",
+        "FEATURE_FLAGS",
+        "FEATURE_FLAG_PREFIX",
+    }