test: fix type errors in inject-live-query test helpers

- Add NonSingleResult to createMockCollection return type since mock
  collections are never singleResult
- Add non-null assertions for collection() signal access in tests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kevin-dp

packages/angular-db/tests/inject-live-query.test.ts

@@ -14,6 +14,7 @@ import type {
   CollectionStatus,
   Context,
   LiveQueryCollectionConfig,
+  NonSingleResult,
   QueryBuilder,
 } from '@tanstack/db'
 
@@ -66,12 +67,13 @@ async function waitForAngularUpdate() {
 function createMockCollection<T extends object, K extends string | number>(
   initial: Array<T & Record<`id`, K>> = [],
   initialStatus: CollectionStatus = `ready`,
-): Collection<T, K, Record<string, never>> & {
-  __setStatus: (s: CollectionStatus) => void
-  __replaceAll: (rows: Array<T & Record<`id`, K>>) => void
-  __upsert: (row: T & Record<`id`, K>) => void
-  __delete: (key: K) => void
-} {
+): Collection<T, K, Record<string, never>> &
+  NonSingleResult & {
+    __setStatus: (s: CollectionStatus) => void
+    __replaceAll: (rows: Array<T & Record<`id`, K>>) => void
+    __upsert: (row: T & Record<`id`, K>) => void
+    __delete: (key: K) => void
+  } {
   const map = new Map<K, T>()
   for (const r of initial) {
     map.set(r.id, r)
@@ -532,7 +534,7 @@ describe(`injectLiveQuery`, () => {
 
       await waitForAngularUpdate()
 
-      expect(res.collection().id).toEqual(expect.any(String))
+      expect(res.collection()!.id).toEqual(expect.any(String))
       expect(res.status()).toBe(`ready`)
       expect(Array.isArray(res.data())).toBe(true)
       expect(res.state() instanceof Map).toBe(true)
@@ -565,7 +567,7 @@ describe(`injectLiveQuery`, () => {
       const res = injectLiveQuery(config)
       await waitForAngularUpdate()
 
-      expect(res.collection().id).toEqual(expect.any(String))
+      expect(res.collection()!.id).toEqual(expect.any(String))
       expect(res.isReady()).toBe(true)
     })
   })
@@ -611,7 +613,7 @@ describe(`injectLiveQuery`, () => {
 
       await waitForAngularUpdate()
 
-      expect(res.collection().id).toEqual(expect.any(String))
+      expect(res.collection()!.id).toEqual(expect.any(String))
       expect(res.status()).toBe(`ready`)
       expect(Array.isArray(res.data())).toBe(true)
       expect(res.state() instanceof Map).toBe(true)
@@ -829,7 +831,7 @@ describe(`injectLiveQuery`, () => {
         })
 
         // Start the live query sync manually
-        liveQueryCollection().preload()
+        liveQueryCollection()!.preload()
 
         await waitForAngularUpdate()
 
@@ -941,7 +943,7 @@ describe(`injectLiveQuery`, () => {
         })
 
         // Start the live query sync manually
-        liveQueryCollection().preload()
+        liveQueryCollection()!.preload()
 
         await waitForAngularUpdate()
 
@@ -1041,7 +1043,7 @@ describe(`injectLiveQuery`, () => {
         })
 
         // Start the live query sync manually
-        liveQueryCollection().preload()
+        liveQueryCollection()!.preload()
 
         await waitForAngularUpdate()