Merge pull request #19136 from github/tausbn/python-modernise-mixed-tuple-returns-query

Python: Modernize `py/mixed-tuple-returns`

python/ql/src/Functions/ReturnConsistentTupleSizes.ql

@@ -4,6 +4,7 @@
  * @kind problem
  * @tags reliability
  *       maintainability
+ *       quality
  * @problem.severity recommendation
  * @sub-severity high
  * @precision high
@@ -11,13 +12,15 @@
  */
 
 import python
+import semmle.python.ApiGraphs
 
-predicate returns_tuple_of_size(Function func, int size, AstNode origin) {
-  exists(Return return, TupleValue val |
+predicate returns_tuple_of_size(Function func, int size, Tuple tuple) {
+  exists(Return return, DataFlow::Node value |
+    value.asExpr() = return.getValue() and
     return.getScope() = func and
-    return.getValue().pointsTo(val, origin)
+    any(DataFlow::LocalSourceNode n | n.asExpr() = tuple).flowsTo(value)
   |
-    size = val.length()
+    size = count(int n | exists(tuple.getElt(n)))
   )
 }
 
@@ -25,6 +28,8 @@ from Function func, int s1, int s2, AstNode t1, AstNode t2
 where
   returns_tuple_of_size(func, s1, t1) and
   returns_tuple_of_size(func, s2, t2) and
-  s1 < s2
+  s1 < s2 and
+  // Don't report on functions that have a return type annotation
+  not exists(func.getDefinition().(FunctionExpr).getReturns())
 select func, func.getQualifiedName() + " returns $@ and $@.", t1, "tuple of size " + s1, t2,
   "tuple of size " + s2