[Python/Reactor] Check for attempts to assign unknown delegates

Author: speth

interfaces/cython/cantera/delegator.pyx

@@ -274,7 +274,9 @@ cdef int assign_delegates(obj, CxxDelegator* delegator) except -1:
     cdef string cxx_name
     cdef string cxx_when
     obj._delegates = []
+    valid_names = set()
     for name, options in obj.delegatable_methods.items():
+        valid_names.add(name)
         if len(options) == 3:
             # Delegate with pre-selected mode, without using prefix on method name
             when = options[2]
@@ -375,6 +377,14 @@ cdef int assign_delegates(obj, CxxDelegator* delegator) except -1:
         # collector
         obj._delegates.append(method)
 
+    # Check for methods on the base object that have no matching delegate
+    for name in dir(obj):
+        if (name.startswith("before_") or name.startswith("after_") or
+            name.startswith("replace_")):
+            base_name = name.split("_", 1)[1]
+            if base_name not in valid_names:
+                raise ValueError(f"'{base_name}' is not a delegatable method")
+
     return 0
 
 

test/python/test_reactor.py

@@ -3115,6 +3115,13 @@ def replace_component_index(self, name):
             r2.component_index("H2")
         assert r2.component_index("succeed") == 0
 
+        class DummyReactor3(ct.ExtensibleReactor):
+            def before_foobar(self, t):
+                pass
+
+        with pytest.raises(ValueError, match="'foobar' is not a delegatable method"):
+            DummyReactor3(self.gas)
+
     def test_delegate_throws(self):
         class TestException(Exception):
             pass