[backport core/1.45] [bugfix] Use Desktop2 bridge for missing model downloads (#12738)

Backport of #12710 to `core/1.45`

Automatically created by backport workflow.

Co-authored-by: jaeone94 <89377375+jaeone94@users.noreply.github.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@comfyorg/comfyui-frontend",
-  "version": "1.45.16",
+  "version": "1.45.15",
   "private": true,
   "description": "Official front-end implementation of ComfyUI",
   "homepage": "https://comfy.org",

src/platform/missingModel/missingModelDownload.test.ts

@@ -35,12 +35,17 @@ vi.mock('@/stores/workspace/sidebarTabStore', () => ({
 
 let testId = 0
 
+beforeEach(() => {
+  vi.restoreAllMocks()
+  vi.resetAllMocks()
+  delete window.__comfyDesktop2
+  delete window.__comfyDesktop2Remote
+})
+
 describe('fetchModelMetadata', () => {
   beforeEach(() => {
-    fetchMock.mockReset()
     mockIsDesktop.value = false
     mockSidebarTabStore.activeSidebarTabId = null
-    mockStartDownload.mockReset()
     testId++
   })
 
@@ -242,7 +247,126 @@ describe('downloadModel', () => {
   beforeEach(() => {
     mockIsDesktop.value = false
     mockSidebarTabStore.activeSidebarTabId = null
-    mockStartDownload.mockReset()
+  })
+
+  it('uses the Desktop2 bridge directly instead of the browser fallback', () => {
+    const anchorClick = vi
+      .spyOn(HTMLAnchorElement.prototype, 'click')
+      .mockImplementation(() => {})
+    const desktopDownloadModel = vi
+      .fn<
+        (url: string, filename: string, directory: string) => Promise<boolean>
+      >()
+      .mockResolvedValue(true)
+    window.__comfyDesktop2 = { downloadModel: desktopDownloadModel }
+
+    downloadModel(
+      {
+        name: 'model.safetensors',
+        url: 'https://huggingface.co/org/model/resolve/main/model.safetensors',
+        directory: 'checkpoints'
+      },
+      { checkpoints: ['/models/checkpoints'] }
+    )
+
+    expect(desktopDownloadModel).toHaveBeenCalledWith(
+      'https://huggingface.co/org/model/resolve/main/model.safetensors',
+      'model.safetensors',
+      'checkpoints'
+    )
+    expect(anchorClick).not.toHaveBeenCalled()
+    expect(mockStartDownload).not.toHaveBeenCalled()
+  })
+
+  it('logs Desktop2 bridge failures without falling back to browser download', async () => {
+    const anchorClick = vi
+      .spyOn(HTMLAnchorElement.prototype, 'click')
+      .mockImplementation(() => {})
+    const consoleError = vi.spyOn(console, 'error').mockImplementation(() => {})
+    const bridgeError = new Error('bridge failed')
+    const desktopDownloadModel = vi
+      .fn<
+        (url: string, filename: string, directory: string) => Promise<boolean>
+      >()
+      .mockRejectedValue(bridgeError)
+    window.__comfyDesktop2 = { downloadModel: desktopDownloadModel }
+
+    downloadModel(
+      {
+        name: 'model.safetensors',
+        url: 'https://huggingface.co/org/model/resolve/main/model.safetensors',
+        directory: 'checkpoints'
+      },
+      { checkpoints: ['/models/checkpoints'] }
+    )
+
+    await vi.waitFor(() => {
+      expect(consoleError).toHaveBeenCalledWith(
+        'Failed to start Desktop2 model download:',
+        bridgeError
+      )
+    })
+    expect(anchorClick).not.toHaveBeenCalled()
+    expect(mockStartDownload).not.toHaveBeenCalled()
+  })
+
+  it('logs synchronous Desktop2 bridge failures without crashing', async () => {
+    const anchorClick = vi
+      .spyOn(HTMLAnchorElement.prototype, 'click')
+      .mockImplementation(() => {})
+    const consoleError = vi.spyOn(console, 'error').mockImplementation(() => {})
+    const bridgeError = new Error('bridge failed before returning a promise')
+    const desktopDownloadModel = vi
+      .fn<
+        (url: string, filename: string, directory: string) => Promise<boolean>
+      >()
+      .mockImplementation(() => {
+        throw bridgeError
+      })
+    window.__comfyDesktop2 = { downloadModel: desktopDownloadModel }
+
+    downloadModel(
+      {
+        name: 'model.safetensors',
+        url: 'https://huggingface.co/org/model/resolve/main/model.safetensors',
+        directory: 'checkpoints'
+      },
+      { checkpoints: ['/models/checkpoints'] }
+    )
+
+    await vi.waitFor(() => {
+      expect(consoleError).toHaveBeenCalledWith(
+        'Failed to start Desktop2 model download:',
+        bridgeError
+      )
+    })
+    expect(anchorClick).not.toHaveBeenCalled()
+    expect(mockStartDownload).not.toHaveBeenCalled()
+  })
+
+  it('keeps remote Desktop2 sessions on the browser fallback', () => {
+    const anchorClick = vi
+      .spyOn(HTMLAnchorElement.prototype, 'click')
+      .mockImplementation(() => {})
+    const desktopDownloadModel = vi
+      .fn<
+        (url: string, filename: string, directory: string) => Promise<boolean>
+      >()
+      .mockResolvedValue(true)
+    window.__comfyDesktop2 = { downloadModel: desktopDownloadModel }
+    window.__comfyDesktop2Remote = true
+
+    downloadModel(
+      {
+        name: 'model.safetensors',
+        url: 'https://huggingface.co/org/model/resolve/main/model.safetensors',
+        directory: 'checkpoints'
+      },
+      { checkpoints: ['/models/checkpoints'] }
+    )
+
+    expect(desktopDownloadModel).not.toHaveBeenCalled()
+    expect(anchorClick).toHaveBeenCalledTimes(1)
   })
 
   it('opens the model library sidebar before starting a desktop download', () => {

src/platform/missingModel/missingModelDownload.ts

@@ -3,6 +3,21 @@ import { isDesktop } from '@/platform/distribution/types'
 import { useElectronDownloadStore } from '@/stores/electronDownloadStore'
 import { useSidebarTabStore } from '@/stores/workspace/sidebarTabStore'
 
+interface ComfyDesktop2Bridge {
+  downloadModel: (
+    url: string,
+    filename: string,
+    directory: string
+  ) => Promise<boolean>
+}
+
+declare global {
+  interface Window {
+    __comfyDesktop2?: ComfyDesktop2Bridge
+    __comfyDesktop2Remote?: boolean
+  }
+}
+
 const ALLOWED_SOURCES = [
   'https://civitai.com/',
   'https://civitai.red/',
@@ -35,6 +50,17 @@ export interface ModelWithUrl {
   directory: string
 }
 
+async function startDesktop2ModelDownload(
+  bridge: ComfyDesktop2Bridge,
+  model: ModelWithUrl
+): Promise<void> {
+  try {
+    await bridge.downloadModel(model.url, model.name, model.directory)
+  } catch (error: unknown) {
+    console.error('Failed to start Desktop2 model download:', error)
+  }
+}
+
 /**
  * Converts a model download URL to a browsable page URL.
  * - HuggingFace: `/resolve/` → `/blob/` (file page with model info)
@@ -63,6 +89,12 @@ export function downloadModel(
   model: ModelWithUrl,
   paths: Record<string, string[]>
 ): void {
+  const desktop2Bridge = window.__comfyDesktop2
+  if (desktop2Bridge?.downloadModel && !window.__comfyDesktop2Remote) {
+    void startDesktop2ModelDownload(desktop2Bridge, model)
+    return
+  }
+
   if (!isDesktop) {
     const link = document.createElement('a')
     link.href = model.url