Apply review feedback to minimal Cortex query (P0-D)

cortex/Query.ts

@@ -23,6 +23,10 @@ function dot(a: Float32Array, b: Float32Array): number {
   return sum;
 }
 
+/**
+ * Concatenates an array of equal-length vectors into a single flat buffer.
+ * @param vectors - Must be non-empty; every element must have the same length.
+ */
 function concatVectors(vectors: Float32Array[]): Float32Array {
   const dim = vectors[0].length;
   const out = new Float32Array(vectors.length * dim);
@@ -129,6 +133,7 @@ export async function query(
   }
 
   const combined = [...hotpathResults, ...coldResults];
+  combined.sort((a, b) => b.score - a.score);
 
   // Update activity for returned pages
   await Promise.all(combined.map(async ({ page }) => {

storage/IndexedDbMetadataStore.ts

@@ -145,7 +145,11 @@ export class IndexedDbMetadataStore implements MetadataStore {
     return this._get<Page>(STORE.pages, pageId);
   }
 
-  /** Returns all pages in the store. Used for warm/cold fallbacks in query. */
+  /**
+   * Returns all pages in the store. Used for warm/cold fallbacks in query.
+   * TODO: Replace with a paginated or indexed scan before production use —
+   * loading every page into memory is expensive for large corpora.
+   */
   async getAllPages(): Promise<Page[]> {
     return new Promise((resolve, reject) => {
       const tx = this.db.transaction(STORE.pages, "readonly");

tests/SalienceEngine.test.ts

@@ -104,7 +104,9 @@ class MockMetadataStore implements MetadataStore {
 
   // --- Stubs for unused MetadataStore methods ---
   async putPage(): Promise<void> { /* stub */ }
-  async getPage(): Promise<undefined> { return undefined; }  async getAllPages(): Promise<any[]> { return []; }  async putBook(): Promise<void> { /* stub */ }
+  async getPage(): Promise<undefined> { return undefined; }
+  async getAllPages(): Promise<any[]> { return []; }
+  async putBook(): Promise<void> { /* stub */ }
   async getBook(): Promise<undefined> { return undefined; }
   async putVolume(): Promise<void> { /* stub */ }
   async getVolume(): Promise<undefined> { return undefined; }

tests/cortex/Query.test.ts

@@ -62,6 +62,44 @@ describe("cortex query (minimal)", () => {
     (globalThis as any).IDBKeyRange = FakeIDBKeyRange;
   });
 
+  it("returns empty results for an empty corpus", async () => {
+    const metadataStore = await IndexedDbMetadataStore.open(freshDbName());
+    const vectorStore = new MemoryVectorStore();
+
+    const backend = new DeterministicDummyEmbeddingBackend({ dimension: 4 });
+    const vectorBackend = new TestVectorBackend();
+
+    const runner = new EmbeddingRunner(async () => ({
+      backend,
+      selectedKind: "dummy" as const,
+      reason: "forced" as const,
+      supportedKinds: ["dummy" as const],
+      measurements: [],
+    }));
+
+    const profile: ModelProfile = {
+      modelId: "test-model",
+      embeddingDimension: 4,
+      contextWindowTokens: 64,
+      truncationTokens: 48,
+      maxChunkTokens: 5,
+      source: "metadata",
+    };
+
+    const result = await query("anything", {
+      modelProfile: profile,
+      embeddingRunner: runner,
+      vectorStore,
+      metadataStore,
+      vectorBackend,
+      topK: 5,
+    });
+
+    expect(result.pages).toHaveLength(0);
+    expect(result.scores).toHaveLength(0);
+    expect(result.metadata.returned).toBe(0);
+  });
+
   it("returns the most relevant page and updates activity", async () => {
     const metadataStore = await IndexedDbMetadataStore.open(freshDbName());
     const vectorStore = new MemoryVectorStore();
@@ -121,4 +159,60 @@ describe("cortex query (minimal)", () => {
     expect(activity?.queryHitCount).toBe(1);
     expect(activity?.lastQueryAt).toBeDefined();
   });
+
+  it("returns results in descending score order (relevance)", async () => {
+    const metadataStore = await IndexedDbMetadataStore.open(freshDbName());
+    const vectorStore = new MemoryVectorStore();
+    const keyPair = await generateKeyPair();
+
+    const backend = new DeterministicDummyEmbeddingBackend({ dimension: 4 });
+    const vectorBackend = new TestVectorBackend();
+
+    const runner = new EmbeddingRunner(async () => ({
+      backend,
+      selectedKind: "dummy" as const,
+      reason: "forced" as const,
+      supportedKinds: ["dummy" as const],
+      measurements: [],
+    }));
+
+    const profile: ModelProfile = {
+      modelId: "test-model",
+      embeddingDimension: 4,
+      contextWindowTokens: 64,
+      truncationTokens: 48,
+      maxChunkTokens: 5,
+      source: "metadata",
+    };
+
+    const text = "One two three four five six seven eight nine ten.";
+    const ingestResult = await ingestText(text, {
+      modelProfile: profile,
+      embeddingRunner: runner,
+      vectorStore,
+      metadataStore,
+      keyPair,
+    });
+
+    expect(ingestResult.pages.length).toBeGreaterThanOrEqual(2);
+
+    const targetPage = ingestResult.pages[0];
+
+    const result = await query(targetPage.content, {
+      modelProfile: profile,
+      embeddingRunner: runner,
+      vectorStore,
+      metadataStore,
+      vectorBackend,
+      topK: ingestResult.pages.length,
+    });
+
+    // Results must include the page whose content matches the query.
+    expect(result.pages.map((p) => p.pageId)).toContain(targetPage.pageId);
+
+    // Scores must be in non-increasing order.
+    for (let i = 1; i < result.scores.length; i++) {
+      expect(result.scores[i]).toBeLessThanOrEqual(result.scores[i - 1]);
+    }
+  });
 });