[fix] Preserve subgraph structure when clearing workflow (#4567)

Co-authored-by: github-actions <github-actions@github.com>

tests-ui/tests/store/subgraphNavigationStore.test.ts

@@ -0,0 +1,113 @@
+import { createPinia, setActivePinia } from 'pinia'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { nextTick } from 'vue'
+
+import { useSubgraphNavigationStore } from '@/stores/subgraphNavigationStore'
+import { useWorkflowStore } from '@/stores/workflowStore'
+import type { ComfyWorkflow } from '@/stores/workflowStore'
+
+vi.mock('@/scripts/app', () => ({
+  app: {
+    graph: {
+      subgraphs: new Map(),
+      getNodeById: vi.fn()
+    },
+    canvas: {
+      subgraph: null
+    }
+  }
+}))
+
+describe('useSubgraphNavigationStore', () => {
+  beforeEach(() => {
+    setActivePinia(createPinia())
+  })
+
+  it('should not clear navigation stack when workflow internal state changes', async () => {
+    const navigationStore = useSubgraphNavigationStore()
+    const workflowStore = useWorkflowStore()
+
+    // Mock a workflow
+    const mockWorkflow = {
+      path: 'test-workflow.json',
+      filename: 'test-workflow.json',
+      changeTracker: null
+    } as ComfyWorkflow
+
+    // Set the active workflow (cast to bypass TypeScript check in test)
+    workflowStore.activeWorkflow = mockWorkflow as any
+
+    // Simulate being in a subgraph by restoring state
+    navigationStore.restoreState(['subgraph-1', 'subgraph-2'])
+
+    expect(navigationStore.exportState()).toHaveLength(2)
+
+    // Simulate a change to the workflow's internal state
+    // (e.g., changeTracker.activeState being reassigned)
+    mockWorkflow.changeTracker = { activeState: {} } as any
+
+    // The navigation stack should NOT be cleared because the path hasn't changed
+    expect(navigationStore.exportState()).toHaveLength(2)
+    expect(navigationStore.exportState()).toEqual(['subgraph-1', 'subgraph-2'])
+  })
+
+  it('should clear navigation stack when switching to a different workflow', async () => {
+    const navigationStore = useSubgraphNavigationStore()
+    const workflowStore = useWorkflowStore()
+
+    // Mock first workflow
+    const workflow1 = {
+      path: 'workflow1.json',
+      filename: 'workflow1.json'
+    } as ComfyWorkflow
+
+    // Set the active workflow
+    workflowStore.activeWorkflow = workflow1 as any
+
+    // Simulate being in a subgraph
+    navigationStore.restoreState(['subgraph-1', 'subgraph-2'])
+
+    expect(navigationStore.exportState()).toHaveLength(2)
+
+    // Switch to a different workflow
+    const workflow2 = {
+      path: 'workflow2.json',
+      filename: 'workflow2.json'
+    } as ComfyWorkflow
+
+    workflowStore.activeWorkflow = workflow2 as any
+
+    // Wait for Vue's reactivity to process the change
+    await nextTick()
+
+    // The navigation stack SHOULD be cleared because we switched workflows
+    expect(navigationStore.exportState()).toHaveLength(0)
+  })
+
+  it('should handle null workflow gracefully', async () => {
+    const navigationStore = useSubgraphNavigationStore()
+    const workflowStore = useWorkflowStore()
+
+    // First set an active workflow
+    const mockWorkflow = {
+      path: 'test-workflow.json',
+      filename: 'test-workflow.json'
+    } as ComfyWorkflow
+
+    workflowStore.activeWorkflow = mockWorkflow as any
+    await nextTick()
+
+    // Add some items to the navigation stack
+    navigationStore.restoreState(['subgraph-1'])
+    expect(navigationStore.exportState()).toHaveLength(1)
+
+    // Set workflow to null
+    workflowStore.activeWorkflow = null
+
+    // Wait for Vue's reactivity to process the change
+    await nextTick()
+
+    // Stack should be cleared when workflow becomes null
+    expect(navigationStore.exportState()).toHaveLength(0)
+  })
+})