feat(memory): add search score explanations (#5102)

Co-authored-by: kartik-mem0 <kartik.labhshetwar@mem0.ai>

mem0-ts/src/oss/tests/scoring.test.ts

@@ -0,0 +1,49 @@
+/// <reference types="jest" />
+
+import { scoreAndRank } from "../src/utils/scoring";
+
+describe("scoreAndRank", () => {
+  const results = [
+    { id: "a", score: 0.8, payload: { data: "mem a" } },
+    { id: "b", score: 0.5, payload: { data: "mem b" } },
+  ];
+
+  it("omits scoreDetails by default", () => {
+    const scored = scoreAndRank(results, {}, {}, 0.1, 10);
+    expect(scored[0].scoreDetails).toBeUndefined();
+    expect(scored[1].scoreDetails).toBeUndefined();
+  });
+
+  it("omits scoreDetails when explain is false", () => {
+    const scored = scoreAndRank(results, {}, {}, 0.1, 10, false);
+    expect(scored[0].scoreDetails).toBeUndefined();
+  });
+
+  it("includes scoreDetails when explain is true", () => {
+    const bm25 = { a: 0.6 };
+    const entity = { a: 0.3 };
+    const scored = scoreAndRank(results, bm25, entity, 0.1, 10, true);
+
+    const details = scored[0].scoreDetails!;
+    expect(details).toBeDefined();
+    expect(details.semanticScore).toBe(0.8);
+    expect(details.bm25Score).toBe(0.6);
+    expect(details.entityBoost).toBe(0.3);
+    expect(details.rawScore).toBeCloseTo(1.7);
+    expect(details.maxPossibleScore).toBe(2.5);
+    expect(details.finalScore).toBeCloseTo(0.68);
+    expect(details.threshold).toBe(0.1);
+  });
+
+  it("includes scoreDetails for results without bm25/entity signals", () => {
+    const scored = scoreAndRank(results, {}, {}, 0.1, 10, true);
+
+    const details = scored[0].scoreDetails!;
+    expect(details.semanticScore).toBe(0.8);
+    expect(details.bm25Score).toBe(0);
+    expect(details.entityBoost).toBe(0);
+    expect(details.rawScore).toBe(0.8);
+    expect(details.maxPossibleScore).toBe(1.0);
+    expect(details.finalScore).toBe(0.8);
+  });
+});