Scheduler: Add tests for bad configuration entries

loki/bulk/configure.py

@@ -126,7 +126,7 @@ class TransformationConfig:
 
     _re_dimension = re.compile(r'\%dimensions\.(.*?)\%')
 
-    def __init__(self, name, module, classname=None, path=None, options=None):
+    def __init__(self, name, module, classname=None, path=None, options={}):
         self.name = name
         self.module = module
         self.classname = classname or self.name
@@ -164,7 +164,7 @@ def instantiate(self):
 
         # Check for and return Transformation class
         if not hasattr(mod, self.classname):
-            raise RuntimeError('Failed to load Transformation class!')
+            raise RuntimeError(f'Failed to load Transformation class: {self.classname}')
 
         # Attempt to instantiate transformation from config
         try:

tests/test_scheduler.py

@@ -2345,6 +2345,37 @@ def test_transformation_config(config):
     assert transformation.module_suffix == '_roll'
     assert not transformation.replace_ignore_items
 
+    # Test for errors when failing to instantiate a transformation
+    bad_config = config.copy()
+    bad_config['transformations'] = {
+        'DependencyTrafo': {  # <= typo
+            'module': 'loki.transform',
+            'options': {}
+        }
+    }
+    with pytest.raises(RuntimeError):
+        cfg = SchedulerConfig.from_dict(bad_config)
+
+    worse_config = config.copy()
+    worse_config['transformations'] = {
+        'DependencyTransform': {
+            'module': 'loki.transformats',  # <= typo
+            'options': {}
+        }
+    }
+    with pytest.raises(ModuleNotFoundError):
+        cfg = SchedulerConfig.from_dict(worse_config)
+
+    worst_config = config.copy()
+    worst_config['transformations'] = {
+        'DependencyTransform': {
+            'module': 'loki.transform',
+            'options': {'hello': 'Dave'}
+        }
+    }
+    with pytest.raises(RuntimeError):
+        cfg = SchedulerConfig.from_dict(worst_config)
+
 
 def test_transformation_config_external_with_dimension(here, config):
     """