fix(plan): ensure changeHook receives finished plan instead of null in finishPlan()

agentscope-core/src/main/java/io/agentscope/core/plan/PlanNotebook.java

@@ -853,18 +853,13 @@ public Mono<String> finishPlan(
 
         currentPlan.finish(state, outcome);
 
+        String message =
+                String.format("The current plan is finished successfully as '%s'.", stateStr);
+
         return storage.addPlan(currentPlan)
-                .then(
-                        Mono.defer(
-                                () -> {
-                                    currentPlan = null;
-                                    return triggerPlanChangeHooks()
-                                            .thenReturn(
-                                                    String.format(
-                                                            "The current plan is finished"
-                                                                    + " successfully as '%s'.",
-                                                            stateStr));
-                                }));
+                .then(triggerPlanChangeHooks())
+                .then(Mono.fromRunnable(() -> currentPlan = null))
+                .thenReturn(message);
     }
 
     /** View the historical plans. */

agentscope-core/src/test/java/io/agentscope/core/plan/PlanNotebookToolTest.java

@@ -806,4 +806,61 @@ void testMultipleHooksAndIdOverwrite() {
         assertEquals(1, count2[0], "hook2 should be called");
         assertEquals(1, count3[0], "New hook1 should be called");
     }
+
+    @Test
+    void testChangeHookReceivesNonNullPlanOnFinishPlan() {
+        Plan[] capturedPlan = {null};
+        notebook.addChangeHook("finishHook", (nb, plan) -> capturedPlan[0] = plan);
+
+        List<SubTask> subtasks = List.of(new SubTask("Task1", "Desc1", "Outcome1"));
+        notebook.createPlanWithSubTasks("Plan", "Desc", "Outcome", subtasks).block();
+
+        notebook.finishPlan("done", "All done").block();
+
+        assertNotNull(capturedPlan[0], "Hook should receive the finished plan, not null");
+        assertEquals("Plan", capturedPlan[0].getName());
+        assertEquals(PlanState.DONE, capturedPlan[0].getState());
+    }
+
+    @Test
+    void testChangeHookReceivesNonNullPlanOnFinishPlanAbandoned() {
+        Plan[] capturedPlan = {null};
+        notebook.addChangeHook("abandonHook", (nb, plan) -> capturedPlan[0] = plan);
+
+        List<SubTask> subtasks = List.of(new SubTask("Task1", "Desc1", "Outcome1"));
+        notebook.createPlanWithSubTasks("Plan", "Desc", "Outcome", subtasks).block();
+
+        notebook.finishPlan("abandoned", "Not needed").block();
+
+        assertNotNull(capturedPlan[0], "Hook should receive the abandoned plan, not null");
+        assertEquals(PlanState.ABANDONED, capturedPlan[0].getState());
+    }
+
+    @Test
+    void testGetCurrentPlanVisibleDuringFinishPlanHook() {
+        Plan[] capturedViaGetter = {null};
+        notebook.addChangeHook(
+                "getterHook", (nb, plan) -> capturedViaGetter[0] = nb.getCurrentPlan());
+
+        List<SubTask> subtasks = List.of(new SubTask("Task1", "Desc1", "Outcome1"));
+        notebook.createPlanWithSubTasks("Plan", "Desc", "Outcome", subtasks).block();
+
+        notebook.finishPlan("done", "Done").block();
+
+        assertNotNull(
+                capturedViaGetter[0],
+                "getCurrentPlan() should return the plan during hook execution");
+        assertEquals("Plan", capturedViaGetter[0].getName());
+    }
+
+    @Test
+    void testCurrentPlanIsNullAfterFinishPlanCompletes() {
+        List<SubTask> subtasks = List.of(new SubTask("Task1", "Desc1", "Outcome1"));
+        notebook.createPlanWithSubTasks("Plan", "Desc", "Outcome", subtasks).block();
+
+        notebook.finishPlan("done", "Done").block();
+
+        assertNull(
+                notebook.getCurrentPlan(), "currentPlan should be null after finishPlan completes");
+    }
 }