Refactor test_dsync for more granular test cases

Author: glennmatthews

pyproject.toml

@@ -49,6 +49,10 @@ extension-pkg-whitelist = [
     "pydantic"
 ]
 
+[tool.pylint.basic]
+# No docstrings required for private methods (Pylint default), or for test_ functions.
+no-docstring-rgx="^(_|test_)"
+
 [tool.pylint.messages_control]
 # Line length is enforced by Black, so pylint doesn't need to check it.
 # Pylint and Black disagree about how to format multi-line arrays; Black wins.

tests/unit/conftest.py

@@ -227,6 +227,31 @@ def backend_a():
     return dsync
 
 
+@pytest.fixture
+def backend_a_with_extra_models():
+    """Provide an instance of BackendA subclass of DSync with some extra sites and devices."""
+    extra_models = BackendA()
+    extra_models.load()
+    extra_site = extra_models.site(name="lax")
+    extra_models.add(extra_site)
+    extra_device = extra_models.device(name="nyc-spine3", site_name="nyc", role="spine")
+    extra_models.get(extra_models.site, "nyc").add_child(extra_device)
+    extra_models.add(extra_device)
+    return extra_models
+
+
+@pytest.fixture
+def backend_a_minus_some_models():
+    """Provide an instance of BackendA subclass of DSync with fewer models than the default."""
+    missing_models = BackendA()
+    missing_models.load()
+    missing_models.remove(missing_models.get(missing_models.site, "rdu"))
+    missing_device = missing_models.get(missing_models.device, "sfo-spine2")
+    missing_models.get(missing_models.site, "sfo").remove_child(missing_device)
+    missing_models.remove(missing_device)
+    return missing_models
+
+
 class ErrorProneSiteA(ErrorProneModel, SiteA):
     """A Site that sometimes throws exceptions."""