Python: fix sub class test

Author: yoff

python/ql/lib/semmle/python/frameworks/Flask.qll

@@ -71,14 +71,21 @@ module Flask {
    * See https://flask.palletsprojects.com/en/1.1.x/api/#flask.Flask.
    */
   module FlaskApp {
-    /** Gets a reference to the `flask.Flask` class. */
-    API::Node classRef() {
-      result = API::moduleImport("flask").getMember("Flask") or
+    /**
+     * Gets a reference to the `flask.Flask` class or any subclass.
+     *
+     * Deprecated: Use `subclassRef()` instead, this predicate always returned some subclasses.
+     */
+    deprecated API::Node classRef() { result = subclassRef() }
+
+    /** Gets a reference to the `flask.Flask` class or any subclass. */
+    API::Node subclassRef() {
+      result = API::moduleImport("flask").getMember("Flask").getASubclass*() or
       result = ModelOutput::getATypeNode("flask.Flask~Subclass").getASubclass*()
     }
 
     /** Gets a reference to an instance of `flask.Flask` (a flask application). */
-    API::Node instance() { result = classRef().getReturn() }
+    API::Node instance() { result = subclassRef().getReturn() }
   }
 
   /**
@@ -132,7 +139,7 @@ module Flask {
     API::Node classRef() {
       result = API::moduleImport("flask").getMember("Response")
       or
-      result = [FlaskApp::classRef(), FlaskApp::instance()].getMember("response_class")
+      result = [FlaskApp::subclassRef(), FlaskApp::instance()].getMember("response_class")
       or
       result = ModelOutput::getATypeNode("flask.Response~Subclass").getASubclass*()
     }

python/ql/test/library-tests/frameworks/flask/flask_subclass.py

@@ -6,7 +6,7 @@ def __init__(self, *args, **kwargs):
         Flask.__init__(self, *args, **kwargs)
 
 
-app = Sub(__name__) # $ MISSING: instance
+app = Sub(__name__) # $ instance
 
 
 @app.route("/")