adds pruning for old briefs

Author: DinosaurDerek

README.md

@@ -4,7 +4,7 @@
 
 This is a demo project showcasing a simple, well-structured backend API using Node.js, Fastify, and TypeScript. It aggregates mock data from multiple crypto-related sources — such as Farcaster posts, CoinDesk articles, and Decrypt news — and returns topic-based summaries with sentiment analysis. While the data is static for now, the architecture is built to support real external APIs.
 
-The API also supports persistent, database-backed briefs: snapshots of topic-based narratives and sentiment, linked to their underlying summaries via a NarrativeRecord relation. These are stored in a PostgreSQL database using Prisma. For demo purposes, daily brief creation is triggered both internally (`node-cron`) and externally (GitHub Actions) — the external trigger is a workaround for free-tier hosting limitations where in-app schedulers can’t run reliably.
+The API also supports persistent, database-backed briefs: snapshots of topic-based narratives and sentiment, linked to their underlying summaries via a NarrativeRecord relation. These are stored in a PostgreSQL database using Prisma. Briefs are created daily and old ones are automatically pruned (keeping only the most recent 7 for demo purposes). For demo purposes, daily brief creation is triggered both internally (`node-cron`) and externally (GitHub Actions) — the external trigger is a workaround for free-tier hosting limitations where in-app schedulers can’t run reliably.
 
 In addition, a full CRUD Notes feature was added for demonstration purposes, showing additional DB interactions and endpoint patterns.
 
@@ -129,14 +129,17 @@ Then run an initial migration:
 yarn testdb:reset
 ```
 
-## Scheduled Jobs
+### Scheduled Jobs
 
-This project includes support for automated daily brief creation.
+This project includes support for automated daily brief creation and cleanup.
 
 ### Local/Production Setup (node-cron)
 
 The codebase includes a `createBriefJob` scheduled task (via `node-cron`) that runs daily at midnight.  
-In a normal production environment (e.g. dedicated server, container with uptime), this would automatically generate a new daily brief without external triggers.
+It will:
+
+- Generate a new daily brief (if one doesn’t already exist).
+- Prune old briefs, keeping only the most recent 7 for demo purposes.
 
 ### Free-tier Hosting Limitation
 
@@ -145,7 +148,7 @@ On free-tier Render, apps sleep when idle. This prevents in-app schedulers like
 ### Workaround (External Trigger)
 
 To make daily jobs run reliably even on free-tier hosting, we use GitHub Actions to call the **`/narratives`** endpoint on a schedule.  
-This wakes the service and triggers daily brief creation externally.
+This wakes the service, creates a new daily brief, and prunes old ones externally.
 
 ---
 

src/jobs/createBriefJob.ts

@@ -1,7 +1,7 @@
 import cron from 'node-cron';
 
 import { getNarratives } from '../api/index.js';
-import { createDailyBriefIfNotExists } from '../utils/brief.js';
+import { createDailyBriefIfNotExists, pruneOldBriefs } from '../utils/brief.js';
 
 // Run every day at midnight
 cron.schedule('0 0 * * *', async () => {
@@ -17,6 +17,11 @@ cron.schedule('0 0 * * *', async () => {
       console.log('Brief already exists, skipping creation');
     }
 
+    const deletedCount = await pruneOldBriefs();
+    if (deletedCount > 0) {
+      console.log(`Pruned ${deletedCount} old brief(s)`);
+    }
+
     console.log('Brief creation job finished');
   } catch (err) {
     console.log('Brief creation job failed', err);

src/routes/narratives.ts

@@ -5,7 +5,7 @@ import { getNarratives } from '../api/index.js';
 import { NarrativeSchema } from '../schemas/narrative.js';
 import { QuerySchema } from '../schemas/query.js';
 import { Query } from '../types/query.js';
-import { createDailyBriefIfNotExists } from '../utils/brief.js';
+import { createDailyBriefIfNotExists, pruneOldBriefs } from '../utils/brief.js';
 
 export default async function (fastify: FastifyInstance) {
   fastify.get<{ Querystring: Query }>(
@@ -38,6 +38,11 @@ export default async function (fastify: FastifyInstance) {
         request.log.info('Brief already exists, skipping generation');
       }
 
+      const deletedCount = await pruneOldBriefs();
+      if (deletedCount > 0) {
+        request.log.info({ deletedCount }, 'Old briefs pruned');
+      }
+
       return narratives;
     }
   );

src/utils/brief.ts

@@ -54,3 +54,18 @@ export async function createDailyBriefIfNotExists(
     throw err;
   }
 }
+
+export async function pruneOldBriefs(limit: number = 7): Promise<number> {
+  const briefs = await prisma.brief.findMany({
+    orderBy: { createdAt: 'desc' },
+    skip: limit,
+  });
+
+  if (briefs.length > 0) {
+    await prisma.brief.deleteMany({
+      where: { id: { in: briefs.map(b => b.id) } },
+    });
+  }
+
+  return briefs.length;
+}

tests/briefUtils.test.ts

@@ -1,10 +1,11 @@
-import { describe, it, expect, beforeEach, afterAll } from 'vitest';
+import { describe, it, expect } from 'vitest';
 
 import { prisma } from '../src/lib/prisma.js';
 import {
   getBriefCreatedAtDate,
   createBrief,
   createDailyBriefIfNotExists,
+  pruneOldBriefs,
 } from '../src/utils/brief.js';
 import type { Narrative } from '../src/types/narrative.js';
 
@@ -83,4 +84,37 @@ describe('brief utils', () => {
     const briefs = await prisma.brief.findMany();
     expect(briefs.length).toBe(1);
   });
+
+  it('prunes old briefs, keeping the latest limit', async () => {
+    // Create 10 briefs on different days
+    const today = new Date();
+    for (let i = 0; i < 10; i++) {
+      const briefDate = new Date(today);
+      briefDate.setUTCDate(today.getUTCDate() - i);
+      await prisma.brief.create({
+        data: {
+          createdAt: briefDate,
+          narratives: {
+            create: [{ topic: `topic${i}`, sentiment: 'neutral' }],
+          },
+        },
+      });
+    }
+
+    // Limit to 7 latest briefs
+    const deletedCount = await pruneOldBriefs(7);
+
+    expect(deletedCount).toBe(3); // 10 - 7 = 3 should be deleted
+
+    const remainingBriefs = await prisma.brief.findMany({
+      orderBy: { createdAt: 'desc' },
+    });
+    expect(remainingBriefs.length).toBe(7);
+
+    // Ensure the newest dates remain
+    const newestDate = remainingBriefs[0].createdAt;
+    const oldestDate = remainingBriefs[6].createdAt;
+    expect(newestDate.getUTCDate()).toBe(today.getUTCDate());
+    expect(oldestDate.getUTCDate()).toBe(today.getUTCDate() - 6);
+  });
 });

tests/narratives.test.ts

@@ -5,6 +5,7 @@ import { TypeBoxTypeProvider } from '@fastify/type-provider-typebox';
 import envSetup from '../src/plugins/env.js';
 import corsSetup from '../src/plugins/cors.js';
 import narrativesRoutes from '../src/routes/narratives.js';
+import { Narrative } from '../src/types/narrative.js';
 
 describe('GET /narratives', () => {
   let app: ReturnType<typeof Fastify>;
@@ -42,7 +43,7 @@ describe('GET /narratives', () => {
     });
 
     expect(response.statusCode).toBe(200);
-    const result = await response.json();
+    const result: Narrative[] = await response.json();
 
     expect(Array.isArray(result)).toBe(true);
     result.forEach(item => {