Implement create custom recommendations

tests/unit/deriveCompactCards.test.ts

@@ -0,0 +1,93 @@
+import { describe, expect, it } from "vitest";
+import { deriveCompactCards } from "../../app/(app)/create/hooks/useFacetRecommendations";
+
+const methods = [
+  { id: "alpha" },
+  { id: "bravo" },
+  { id: "charlie" },
+  { id: "delta" },
+  { id: "echo" },
+  { id: "foxtrot" },
+  { id: "golf" },
+] as const;
+
+describe("deriveCompactCards", () => {
+  it("falls back to authoring order with no badges when no facets selected", () => {
+    const result = deriveCompactCards(methods, {}, false, 5);
+    expect(result.compactCardIds).toEqual([
+      "alpha",
+      "bravo",
+      "charlie",
+      "delta",
+      "echo",
+    ]);
+    expect(result.recommendedIds.size).toBe(0);
+  });
+
+  it("falls back to authoring order with no badges when facets selected but every score is zero", () => {
+    const result = deriveCompactCards(methods, {}, true, 5);
+    expect(result.compactCardIds).toEqual([
+      "alpha",
+      "bravo",
+      "charlie",
+      "delta",
+      "echo",
+    ]);
+    expect(result.recommendedIds.size).toBe(0);
+  });
+
+  it("shows only recommended (matched) cards when fewer than the limit match", () => {
+    const result = deriveCompactCards(
+      methods,
+      { bravo: 2, delta: 1 },
+      true,
+      5,
+    );
+    // Caller is responsible for pre-ranking by score (rankMethodsByScore).
+    // This test passes already-ranked input; the hook just respects ordering
+    // and tags only the matched subset — no padding with unrecommended cards.
+    expect(result.compactCardIds).toEqual(["bravo", "delta"]);
+    expect([...result.recommendedIds].sort()).toEqual(["bravo", "delta"]);
+  });
+
+  it("caps recommended cards at the limit when more than `limit` match", () => {
+    const scores = {
+      alpha: 4,
+      bravo: 3,
+      charlie: 3,
+      delta: 2,
+      echo: 1,
+      foxtrot: 1,
+      golf: 1,
+    };
+    const result = deriveCompactCards(methods, scores, true, 5);
+    expect(result.compactCardIds).toEqual([
+      "alpha",
+      "bravo",
+      "charlie",
+      "delta",
+      "echo",
+    ]);
+    expect(result.recommendedIds.size).toBe(5);
+    expect([...result.recommendedIds].sort()).toEqual([
+      "alpha",
+      "bravo",
+      "charlie",
+      "delta",
+      "echo",
+    ]);
+  });
+
+  it("returns a single card when only one method matches", () => {
+    const result = deriveCompactCards(methods, { charlie: 4 }, true, 5);
+    expect(result.compactCardIds).toEqual(["charlie"]);
+    expect([...result.recommendedIds]).toEqual(["charlie"]);
+  });
+
+  it("respects a smaller `limit` even when many methods match", () => {
+    const scores = { alpha: 4, bravo: 3, charlie: 3, delta: 2 };
+    const result = deriveCompactCards(methods, scores, true, 3);
+    expect(result.compactCardIds).toEqual(["alpha", "bravo", "charlie"]);
+    expect(result.recommendedIds.size).toBe(3);
+  });
+});