JS: IteratorExceptionStep

javascript/ql/src/semmle/javascript/StandardLibrary.qll

@@ -74,23 +74,13 @@ private class ArrayIterationCallbackAsPartialInvoke extends DataFlow::PartialInv
  * A flow step propagating the exception thrown from a callback to a method whose name coincides
  * a built-in Array iteration method, such as `forEach` or `map`.
  */
-private class IteratorExceptionStep extends DataFlow::MethodCallNode, DataFlow::AdditionalFlowStep {
-  IteratorExceptionStep() {
-    exists(string name | name = getMethodName() |
-      name = "forEach" or
-      name = "each" or
-      name = "map" or
-      name = "filter" or
-      name = "some" or
-      name = "every" or
-      name = "fold" or
-      name = "reduce"
-    )
-  }
-
+private class IteratorExceptionStep extends DataFlow::SharedFlowStep {
   override predicate step(DataFlow::Node pred, DataFlow::Node succ) {
-    pred = getAnArgument().(DataFlow::FunctionNode).getExceptionalReturn() and
-    succ = this.getExceptionalReturn()
+    exists(DataFlow::MethodCallNode call |
+      call.getMethodName() = ["forEach", "each", "map", "filter", "some", "every", "fold", "reduce"] and
+      pred = call.getAnArgument().(DataFlow::FunctionNode).getExceptionalReturn() and
+      succ = call.getExceptionalReturn()
+    )
   }
 }