Test swig runtime module contains expected names

Examples/test-suite/python/python_moduleimport_runme.py

@@ -1,7 +1,24 @@
 import python_moduleimport
 
+# Test custom moduleimport in %module
 if python_moduleimport.simple_function(99) != 99:
     raise RuntimeError("simple_function")
 
 if python_moduleimport.extra_import_variable != "custom import of _python_moduleimport":
     raise RuntimeError("custom import")
+
+
+# Test the swig runtime module contains the expected names/types
+import importlib
+swig_runtime_version = python_moduleimport.runtime_version()
+swig_runtime_data = importlib.import_module("swig_runtime_data" + swig_runtime_version) # Equivalent to (for version 5): import swig_runtime_data5 as swig_runtime_data
+
+names = dir(swig_runtime_data)
+expected_names = ("SwigPyObject", "SwigPyPacked", "SwigVarLink")
+for name in expected_names:
+    if name not in names:
+        raise RuntimeError("{} not in {}".format(name, names))
+
+cvar_type = type(python_moduleimport.cvar)
+if cvar_type.__name__ != "SwigVarLink":
+    raise RuntimeError("cvar type name is incorrect: {}".format(cvar_type.__name__))

Examples/test-suite/python_moduleimport.i

@@ -23,4 +23,6 @@ from $module import *
 
 %inline %{
 int simple_function(int i) { return i; }
+int globalvar = 99;
+const char * runtime_version() { return SWIG_RUNTIME_VERSION; }
 %}