From 731799aceaeb611fdec7e7e9150a483e8a3f7da9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mateusz=20Burzy=C5=84ski?= <mateuszburzynski@gmail.com>
Date: Mon, 23 Oct 2023 16:47:36 +0200
Subject: [PATCH] Do not resolve `output` of final states directly nested in
 parallel states (#4386)

* Do not resolve `output` of final states directly nested in parallel states

* simplify the while loop through parallel ancestry chain

* rewrite test to fix the CI
---
 packages/core/src/stateUtils.ts  | 32 +++++++++++---------------------
 packages/core/test/final.test.ts | 29 +++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 21 deletions(-)

diff --git a/packages/core/src/stateUtils.ts b/packages/core/src/stateUtils.ts
index 72b84630ae..f1f2265b02 100644
--- a/packages/core/src/stateUtils.ts
+++ b/packages/core/src/stateUtils.ts
@@ -1157,16 +1157,11 @@ function enterStates(
     if (stateNodeToEnter.type === 'final') {
       const parent = stateNodeToEnter.parent;
 
-      if (completedNodes.has(parent)) {
-        continue;
-      }
-      completedNodes.add(parent);
-
       let ancestorMarker =
         parent?.type === 'parallel' ? parent : parent?.parent;
       let rootCompletionNode = ancestorMarker || stateNodeToEnter;
 
-      if (ancestorMarker) {
+      if (parent?.type === 'compound') {
         internalQueue.push(
           createDoneStateEvent(
             parent!.id,
@@ -1180,21 +1175,16 @@ function enterStates(
               : undefined
           )
         );
-        while (
-          ancestorMarker?.type === 'parallel' &&
-          isInFinalState(mutConfiguration, ancestorMarker)
-        ) {
-          const completedNode: typeof ancestorMarker = ancestorMarker;
-
-          ancestorMarker = completedNode.parent;
-          rootCompletionNode = completedNode;
-
-          if (completedNodes.has(completedNode)) {
-            break;
-          }
-          completedNodes.add(completedNode);
-          internalQueue.push(createDoneStateEvent(completedNode.id));
-        }
+      }
+      while (
+        ancestorMarker?.type === 'parallel' &&
+        !completedNodes.has(ancestorMarker) &&
+        isInFinalState(mutConfiguration, ancestorMarker)
+      ) {
+        completedNodes.add(ancestorMarker);
+        internalQueue.push(createDoneStateEvent(ancestorMarker.id));
+        rootCompletionNode = ancestorMarker;
+        ancestorMarker = ancestorMarker.parent;
       }
       if (ancestorMarker) {
         continue;
diff --git a/packages/core/test/final.test.ts b/packages/core/test/final.test.ts
index 1dd7d2401e..9bbba070a9 100644
--- a/packages/core/test/final.test.ts
+++ b/packages/core/test/final.test.ts
@@ -1080,4 +1080,33 @@ describe('final states', () => {
 
     expect(actorRef.getSnapshot().status).toBe('active');
   });
+
+  it('should not resolve output of a final state if its parent is a parallel state', () => {
+    const spy = jest.fn();
+
+    const machine = createMachine({
+      initial: 'A',
+      states: {
+        A: {
+          type: 'parallel',
+          states: {
+            B: {
+              type: 'final',
+              output: spy
+            },
+            C: {
+              initial: 'C1',
+              states: {
+                C1: {}
+              }
+            }
+          }
+        }
+      }
+    });
+
+    createActor(machine).start();
+
+    expect(spy).not.toHaveBeenCalled();
+  });
 });