feat(db): recordView/listViews fuer recipe_view

INSERT OR REPLACE fuer idempotenten Bump des last_viewed_at Timestamps.
listViews-Helper nur fuer Tests; Sort-Query laeuft direkt in
listAllRecipesPaginated via LEFT JOIN.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/server/recipes/views.ts

@@ -0,0 +1,35 @@
+import type Database from 'better-sqlite3';
+
+export function recordView(
+  db: Database.Database,
+  profileId: number,
+  recipeId: number
+): void {
+  // INSERT OR REPLACE re-fires the DEFAULT (CURRENT_TIMESTAMP) on conflict,
+  // so subsequent views of the same recipe by the same profile bump the
+  // timestamp without breaking the composite PK.
+  db.prepare(
+    `INSERT OR REPLACE INTO recipe_view (profile_id, recipe_id)
+     VALUES (?, ?)`
+  ).run(profileId, recipeId);
+}
+
+export type ViewRow = {
+  profile_id: number;
+  recipe_id: number;
+  last_viewed_at: string;
+};
+
+export function listViews(
+  db: Database.Database,
+  profileId: number
+): ViewRow[] {
+  return db
+    .prepare(
+      `SELECT profile_id, recipe_id, last_viewed_at
+         FROM recipe_view
+        WHERE profile_id = ?
+        ORDER BY last_viewed_at DESC`
+    )
+    .all(profileId) as ViewRow[];
+}

tests/integration/recipe-views.test.ts

@@ -1,5 +1,14 @@
 import { describe, it, expect } from 'vitest';
 import { openInMemoryForTest } from '../../src/lib/server/db';
+import { recordView, listViews } from '../../src/lib/server/recipes/views';
+import { createProfile } from '../../src/lib/server/profiles/repository';
+
+function seedRecipe(db: ReturnType<typeof openInMemoryForTest>, title: string): number {
+  const r = db
+    .prepare("INSERT INTO recipe (title, created_at) VALUES (?, datetime('now')) RETURNING id")
+    .get(title) as { id: number };
+  return r.id;
+}
 
 describe('014_recipe_views migration', () => {
   it('creates recipe_view table with expected columns', () => {
@@ -29,3 +38,47 @@ describe('014_recipe_views migration', () => {
     expect(idxList.some((i) => i.name === 'idx_recipe_view_recent')).toBe(true);
   });
 });
+
+describe('recordView', () => {
+  it('inserts a view row with default timestamp', () => {
+    const db = openInMemoryForTest();
+    const profile = createProfile(db, 'Test');
+    const recipeId = seedRecipe(db, 'Pasta');
+
+    recordView(db, profile.id, recipeId);
+
+    const rows = listViews(db, profile.id);
+    expect(rows.length).toBe(1);
+    expect(rows[0].recipe_id).toBe(recipeId);
+    expect(rows[0].last_viewed_at).toMatch(/^\d{4}-\d{2}-\d{2}/);
+  });
+
+  it('updates timestamp on subsequent view of same recipe', async () => {
+    const db = openInMemoryForTest();
+    const profile = createProfile(db, 'Test');
+    const recipeId = seedRecipe(db, 'Pasta');
+
+    recordView(db, profile.id, recipeId);
+    const first = listViews(db, profile.id)[0].last_viewed_at;
+
+    // tiny delay so the second timestamp differs
+    await new Promise((r) => setTimeout(r, 1100));
+    recordView(db, profile.id, recipeId);
+
+    const rows = listViews(db, profile.id);
+    expect(rows.length).toBe(1);
+    expect(rows[0].last_viewed_at >= first).toBe(true);
+  });
+
+  it('throws on unknown profile_id (FK)', () => {
+    const db = openInMemoryForTest();
+    const recipeId = seedRecipe(db, 'Pasta');
+    expect(() => recordView(db, 999, recipeId)).toThrow();
+  });
+
+  it('throws on unknown recipe_id (FK)', () => {
+    const db = openInMemoryForTest();
+    const profile = createProfile(db, 'Test');
+    expect(() => recordView(db, profile.id, 999)).toThrow();
+  });
+});