Python: fix sub class test

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/src/meta/ClassHierarchy/Find.ql

@@ -351,7 +351,7 @@ class DjangoHttpRequest extends FindSubclassesSpec {
 class FlaskClass extends FindSubclassesSpec {
   FlaskClass() { this = "flask.Flask~Subclass" }
 
-  override API::Node getAlreadyModeledClass() { result = Flask::FlaskApp::classRef() }
+  override API::Node getAlreadyModeledClass() { result = Flask::FlaskApp::subclassRef() }
 }
 
 class FlaskBlueprint extends FindSubclassesSpec {

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

@@ -6,9 +6,9 @@ class Sub(Flask):
         Flask.__init__(self, *args, **kwargs)
 
 
-app = Sub(__name__) # $ MISSING: instance
+app = Sub(__name__) # $ instance
 
 
-@app.route("/")
-def hello():
-    return "world"
+@app.route("/") # $ routeSetup="/"
+def hello(): # $ requestHandler
+    return "world" # $ HttpResponse