Python: test the MaD path for constructor calls

Author: yoff

python/ql/test/library-tests/dataflow/model-summaries/NormalDataflowTest.ext.yml

@@ -18,4 +18,6 @@ extensions:
       - ["foo", "Member[MS_spread]", "Argument[0]", "ReturnValue.TupleElement[0]", "value"]
       - ["foo", "Member[MS_spread]", "Argument[1]", "ReturnValue.TupleElement[1]", "value"]
       - ["foo", "Member[MS_spread_all]", "Argument[0]", "ReturnValue.TupleElement[0,1]", "value"]
+      - ["foo", "Member[MS_Class].Call", "Argument[0, x:]", "ReturnValue", "value"]
+      - ["foo", "Member[MS_Class_transitive].Subclass.Call", "Argument[0, x:]", "ReturnValue", "value"]
       - ["json", "Member[MS_loads]", "Argument[0]", "ReturnValue", "taint"]

python/ql/test/library-tests/dataflow/model-summaries/model_summaries.py

@@ -122,6 +122,24 @@ def explicit_identity(x):
 SINK(a)  # $ flow="SOURCE, l:-1 -> a"
 SINK(b)  # $ flow="SOURCE, l:-2 -> b"
 
+from foo import MS_Class, MS_Class_transitive
+
+# Class summaries
+class_via_positional = MS_Class(SOURCE)
+SINK(class_via_positional)  # $ flow="SOURCE, l:-1 -> class_via_positional"
+
+class_via_kw = MS_Class(x = SOURCE)
+SINK(class_via_kw)  # $ flow="SOURCE, l:-1 -> class_via_kw"
+
+class C(MS_Class_transitive):
+    pass
+
+subclass_via_positional = C(SOURCE)
+SINK(subclass_via_positional)  # $ flow="SOURCE, l:-1 -> subclass_via_positional"
+
+subclass_via_kw = C(x = SOURCE)
+SINK(subclass_via_kw)  # $ flow="SOURCE, l:-1 -> subclass_via_kw"
+
 # Modeled flow-summary is not value preserving
 from json import MS_loads as json_loads