fix(desktop): reject incomplete update feeds

Author: waleedlatif1

apps/sim/app/api/desktop/update/download/route.test.ts

@@ -126,6 +126,17 @@ describe('desktop update download route', () => {
     })
   })
 
+  it('reports an invalid feed when every release candidate is rejected', async () => {
+    const incomplete = release('v1.4.0', DESKTOP_STABLE_RELEASE_REPOSITORY)
+    incomplete.assets = incomplete.assets.filter((asset) => asset.name === MANIFEST_ASSET_NAME)
+    mockReleases([incomplete])
+
+    const response = await getDownload()
+
+    expect(response.status).toBe(502)
+    expect(await response.json()).toMatchObject({ error: 'Release installer unavailable' })
+  })
+
   it('surfaces an unreadable release list instead of redirecting', async () => {
     fetchMock.mockResolvedValueOnce(new Response(null, { status: 500 }))
 

apps/sim/app/api/desktop/update/download/route.ts

@@ -87,6 +87,9 @@ export const GET = withRouteHandler(async (_request: NextRequest): Promise<Respo
   }
 
   if (!resolved.release) {
+    if (resolved.rejectedCandidates) {
+      return NextResponse.json({ error: 'Release installer unavailable' }, { status: 502 })
+    }
     return NextResponse.json(
       { error: `No desktop release for channel ${channel}` },
       { status: 404 }

apps/sim/lib/desktop/update-feed.test.ts

@@ -194,4 +194,16 @@ describe('rewriteManifestUrls', () => {
       rewriteManifestUrls(manifest, 'v0.5.24', DESKTOP_STABLE_RELEASE_REPOSITORY, new Set())
     ).toBeNull()
   })
+
+  it('rejects a manifest without an updater file entry', () => {
+    const manifest = ['version: 0.5.24', 'files: []', 'path: Sim-0.5.24-universal.zip'].join('\n')
+    expect(
+      rewriteManifestUrls(
+        manifest,
+        'v0.5.24',
+        DESKTOP_STABLE_RELEASE_REPOSITORY,
+        new Set(['Sim-0.5.24-universal.zip'])
+      )
+    ).toBeNull()
+  })
 })

apps/sim/lib/desktop/update-feed.ts

@@ -131,6 +131,7 @@ export function rewriteManifestUrls(
   const version = tag.replace(/^v/, '')
   const expectedNames = new Set([`Sim-${version}-universal.dmg`, `Sim-${version}-universal.zip`])
   let valid = true
+  let hasUpdaterFile = false
   const rewritten = manifest.replace(
     /^(\s*(?:-\s*)?(?:url|path):\s*)(\S+)\s*$/gm,
     (_line, prefix: string, value: string) => {
@@ -144,14 +145,15 @@ export function rewriteManifestUrls(
           valid = false
           return ''
         }
+        if (/\burl:\s*$/.test(prefix)) hasUpdaterFile = true
         return `${prefix}${base}${encodeURIComponent(name)}`
       } catch {
         valid = false
         return ''
       }
     }
   )
-  return valid ? rewritten : null
+  return valid && hasUpdaterFile ? rewritten : null
 }
 
 /**