Fix starter pack navigation from search and explore (#11563)

src/screens/StarterPack/StarterPackScreen.tsx

@@ -147,10 +147,7 @@ export function StarterPackScreenInner({
   const isValid =
     starterPack &&
     (starterPack.list || starterPack?.creator?.did === currentAccount?.did) &&
-    // Cards may precache a synthetic full view while navigating. Its list CID
-    // is intentionally empty until the server response replaces it, so use
-    // the trusted app-view discriminator here instead of strict validation.
-    bsky.isType(app.bsky.graph.defs.starterPackView, starterPack) &&
+    bsky.starterPack.isTrustedView(starterPack) &&
     bsky.matches(app.bsky.graph.starterpack, starterPack.record)
 
   if (!did || !starterPack || !isValid || !moderationOpts) {

src/types/bsky/__tests__/starterPack.test.ts

@@ -1,7 +1,11 @@
-import {type app} from '#/lexicons'
+/* Full schema matching exercises CID validation, so use the real CID parser. */
+jest.unmock('multiformats/cid')
+
+import {app} from '#/lexicons'
 import {
   type AnyStarterPackView,
   isBasicView,
+  isTrustedView,
   isView,
 } from '#/types/bsky/starterPack'
 
@@ -9,15 +13,21 @@ const now = () => new Date().toISOString()
 
 const creator = {
   $type: 'app.bsky.actor.defs#profileViewBasic',
-  did: 'did:plc:abc',
-  handle: 'alice.test',
+  did: 'did:plc:qrllvid7s54k4hnwtqxwetrf',
+  handle: 'joshuajfriedman.com',
 }
 
 const basicView = {
   $type: 'app.bsky.graph.defs#starterPackViewBasic',
-  uri: 'at://did:plc:abc/app.bsky.graph.starterpack/123',
-  cid: 'bafypack',
-  record: {},
+  uri: 'at://did:plc:qrllvid7s54k4hnwtqxwetrf/app.bsky.graph.starterpack/3l4poszxde32k',
+  cid: 'bafyreiaxduxpwdpjgvve3klfs4flkwjwfqiurszw4o6jvjarpqqmeqwiza',
+  record: {
+    $type: 'app.bsky.graph.starterpack',
+    createdAt: '2024-09-22T03:52:03.686Z',
+    feeds: [],
+    list: 'at://did:plc:qrllvid7s54k4hnwtqxwetrf/app.bsky.graph.list/3l4posztwzy2e',
+    name: 'Bluesky for Art History',
+  },
   creator,
   indexedAt: now(),
 }
@@ -27,6 +37,18 @@ const fullView = {
   $type: 'app.bsky.graph.defs#starterPackView',
 }
 
+const {$type: _, ...directFullView} = fullView
+
+const syntheticFullView = {
+  ...fullView,
+  list: {
+    uri: 'at://did:plc:abc/app.bsky.graph.list/123',
+    cid: '',
+    name: 'Starter pack',
+    purpose: 'app.bsky.graph.defs#referencelist',
+  },
+}
+
 /*
  * Type-level assertions for the view alias: it must accept both the basic and
  * the full starter pack view. Compile-time only - a failure surfaces as a
@@ -76,6 +98,23 @@ describe('types/bsky/starterPack guards', () => {
     })
   })
 
+  describe('isTrustedView', () => {
+    it('accepts a direct full view with an omitted $type', () => {
+      expect(isTrustedView(directFullView)).toBe(true)
+    })
+
+    it('accepts a typed synthetic view with placeholder fields', () => {
+      expect(
+        app.bsky.graph.defs.starterPackView.matches(syntheticFullView),
+      ).toBe(false)
+      expect(isTrustedView(syntheticFullView)).toBe(true)
+    })
+
+    it('rejects the basic view', () => {
+      expect(isTrustedView(basicView)).toBe(false)
+    })
+  })
+
   it('narrows a view from either world to a readable shape', () => {
     /*
      * The `$type` string is world-independent, so one guard narrows values from

src/types/bsky/starterPack.ts

@@ -25,6 +25,19 @@ export function isView(v: unknown): v is app.bsky.graph.defs.StarterPackView {
   )
 }
 
+/**
+ * Accepts both forms of a full starter pack view used by the app:
+ *
+ * - direct lexicon refs returned by the app view, where `$type` may be omitted
+ * - trusted synthetic cache entries, which carry `$type` but may contain
+ *   placeholder fields that do not yet pass full schema validation
+ */
+export function isTrustedView(
+  v: unknown,
+): v is app.bsky.graph.defs.StarterPackView {
+  return isView(v) || app.bsky.graph.defs.starterPackView.matches(v)
+}
+
 /**
  * Matches any starter pack view exported by our SDK.
  */