test: lock in /assets/ path prefix as part of the contract

Add a hashed CSS asset under a non-/assets/ path to assert the path
prefix is required, not just the extension.

Addresses review feedback:
https://github.com/Comfy-Org/ComfyUI_frontend/pull/9945#discussion_r3158251424

src/App.vue

@@ -8,16 +8,19 @@
 import { captureException } from '@sentry/vue'
 import BlockUI from 'primevue/blockui'
 import { computed, onMounted, watch } from 'vue'
+import { useI18n } from 'vue-i18n'
 
 import GlobalDialog from '@/components/dialog/GlobalDialog.vue'
 import config from '@/config'
 import { isDesktop } from '@/platform/distribution/types'
+import { useToastStore } from '@/platform/updates/common/toastStore'
 import { app } from '@/scripts/app'
 import { useWorkspaceStore } from '@/stores/workspaceStore'
 import { electronAPI } from '@/utils/envUtil'
-import { parsePreloadError } from '@/utils/preloadErrorUtil'
+import { isStaleChunkError, parsePreloadError } from '@/utils/preloadErrorUtil'
 import { useConflictDetection } from '@/workbench/extensions/manager/composables/useConflictDetection'
 
+const { t } = useI18n()
 const workspaceStore = useWorkspaceStore()
 app.extensionManager = useWorkspaceStore()
 
@@ -92,17 +95,14 @@ onMounted(() => {
         }
       })
     }
-    // Disabled: Third-party custom node extensions frequently trigger this toast
-    // (e.g., bare "vue" imports, wrong relative paths to scripts/app.js, missing
-    // core dependencies). These are plugin bugs, not ComfyUI core failures, but
-    // the generic error message alarms users and offers no actionable guidance.
-    // The console.error above still logs the details for developers to debug.
-    // useToastStore().add({
-    //   severity: 'error',
-    //   summary: t('g.preloadErrorTitle'),
-    //   detail: t('g.preloadError'),
-    //   life: 10000
-    // })
+    if (isStaleChunkError(info)) {
+      useToastStore().add({
+        severity: 'error',
+        summary: t('g.preloadErrorTitle'),
+        detail: t('g.preloadError'),
+        life: 10000
+      })
+    }
   })
 
   // Capture resource load failures (CSS, scripts) in non-localhost distributions

src/utils/preloadErrorUtil.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest'
 
-import { parsePreloadError } from './preloadErrorUtil'
+import { isStaleChunkError, parsePreloadError } from './preloadErrorUtil'
 
 describe('parsePreloadError', () => {
   it('parses CSS preload error', () => {
@@ -90,3 +90,96 @@ describe('parsePreloadError', () => {
     expect(result.chunkName).toBe('index')
   })
 })
+
+describe('isStaleChunkError', () => {
+  it('returns true for hashed JS chunk under /assets/', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: /assets/vendor-vue-core-abc123.js'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(true)
+  })
+
+  it('returns true for hashed CSS chunk under /assets/', () => {
+    const info = parsePreloadError(
+      new Error('Unable to preload CSS for /assets/style-9f8e7d.css')
+    )
+    expect(isStaleChunkError(info)).toBe(true)
+  })
+
+  it('returns true for hashed mjs chunk under /assets/', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: /assets/chunk-abc123.mjs'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(true)
+  })
+
+  it('returns true for base64 (mixed-case) hashed chunk under /assets/', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: /assets/vendor-Bx7_ab2.js'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(true)
+  })
+
+  it('returns false for non-asset URLs like /api/i18n', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: https://cloud.comfy.org/api/i18n'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(false)
+  })
+
+  it('returns false for unhashed asset files', () => {
+    const info = parsePreloadError(
+      new Error('Failed to fetch dynamically imported module: /assets/index.js')
+    )
+    expect(isStaleChunkError(info)).toBe(false)
+  })
+
+  it('returns false for hashed assets outside /assets/', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: /static/style-abc123.css'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(false)
+  })
+
+  it('returns false when no URL can be extracted', () => {
+    const info = parsePreloadError(new Error('Something failed'))
+    expect(isStaleChunkError(info)).toBe(false)
+  })
+
+  it('returns false for font files', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: /assets/inter-abc123.woff2'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(false)
+  })
+
+  it('returns false for image files', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: /assets/logo-abc123.png'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(false)
+  })
+
+  it('returns true for full URL with hashed asset path', () => {
+    const info = parsePreloadError(
+      new Error(
+        'Failed to fetch dynamically imported module: https://cloud.comfy.org/assets/vendor-three-def456.js'
+      )
+    )
+    expect(isStaleChunkError(info)).toBe(true)
+  })
+})

src/utils/preloadErrorUtil.ts

@@ -64,6 +64,21 @@ function extractChunkName(url: string): string | null {
   return withoutHash || null
 }
 
+const HASHED_ASSET_RE = /\/assets\/.+-[A-Za-z0-9_-]{6,}\.(js|mjs|css)$/
+
+/**
+ * Determines if a preload error is a genuine stale chunk error — i.e. a hashed
+ * JS/CSS asset under /assets/ that 404'd, typically after a new deployment
+ * changed chunk hashes. Returns false for non-asset URLs (e.g. /api/i18n),
+ * unknown file types, and errors with no extractable URL.
+ */
+export function isStaleChunkError(info: PreloadErrorInfo): boolean {
+  if (!info.url) return false
+
+  const pathname = new URL(info.url, 'https://cloud.comfy.org').pathname
+  return HASHED_ASSET_RE.test(pathname)
+}
+
 export function parsePreloadError(error: Error): PreloadErrorInfo {
   const message = error.message || String(error)
   const url = extractUrl(message)