Improve error message for inconsistent types in _multimap_array_container_impl

Author: inducer

arraycontext/container/traversal.py

@@ -244,9 +244,16 @@ def rec(*args_: Any) -> Any:
         except NotAnArrayContainerError:
             return f(*args_)
 
-        assert all(
-                type(args_[i]) is type(template_ary) for i in container_indices[1:]
-                ), f"expected type '{type(template_ary).__name__}'"
+        if __debug__:  # noqa: SIM102
+            if not all(
+                        type(args_[i]) is type(template_ary)
+                        for i in container_indices[1:]
+                    ):
+                arg_summary = ", ".join(
+                    f"arg{i+1}: {type(arg)}"
+                    for i, arg in enumerate(args_))
+                raise TypeError(
+                    f"inconsistent types in multiple traversal: {arg_summary}")
 
         result = []
         new_args = list(args_)

test/test_arraycontext.py

@@ -802,7 +802,7 @@ def check_leaf(a, subary1, b, subary2):
     for ary in [ary_dof, ary_of_dofs, mat_of_dofs, dc_of_dofs]:
         check_leaf(2, ary, 2, ary)
 
-    with pytest.raises(AssertionError):
+    with pytest.raises(TypeError):
         rec_multimap_array_container(func_multiple_scalar, 2, ary_dof, 2, dc_of_dofs)
 
     # }}}