Python: Also capture alias with new name

python/ql/lib/semmle/python/frameworks/internal/SubclassFinder.qll

@@ -190,11 +190,12 @@ module NotExposed {
     string relevantName, Location loc
   ) {
     loc = mod.getLocation() and
-    exists(API::Node relevantClass, ClassExpr classExpr |
+    exists(API::Node relevantClass, Expr value |
       relevantClass = newOrExistingModeling(spec).getASubclass*() and
       ImportResolution::module_export(mod, relevantName, def) and
-      classExpr = relevantClass.asSource().asExpr() and
-      classExpr = def.asVar().getDefinition().(AssignmentDefinition).getValue().getNode()
+      value = relevantClass.getAValueReachableFromSource().asExpr() and
+      value = def.asVar().getDefinition().(AssignmentDefinition).getValue().getNode()
+      // value could be a ClassExpr if a new class is defined, or a Name if defining an alias
     ) and
     (
       mod.isPackageInit() and

python/ql/test/experimental/library-tests/FindSubclass/Find.expected

@@ -1,3 +1,4 @@
 | flask.View~Subclass | find_subclass_test | Member[A] |
 | flask.View~Subclass | find_subclass_test | Member[B] |
+| flask.View~Subclass | find_subclass_test | Member[ViewAlias] |
 | flask.View~Subclass | find_subclass_test | Member[View] |

python/ql/test/experimental/library-tests/FindSubclass/find_subclass_test.py

@@ -5,3 +5,6 @@ class A(View):
 
 class B(A):
     pass
+
+
+ViewAlias = View