From 3f2d84bf622528bb0a41ed724c7f7018764d05eb Mon Sep 17 00:00:00 2001
From: lebaudantoine <lebaud.antoine131@gmail.com>
Date: Wed, 21 May 2025 11:49:53 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9B(y-provider)=20increase=20JSON=20si?=
 =?UTF-8?q?ze=20limits=20for=20transcription=20conversion?=
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Problem:
- Default Express JSON parser limit (100kb) is insufficient for larger
 transcription files
- 2-hour audio transcriptions slightly exceed the 100kb limit, causing request
 failures

Solution:
- Implemented custom middleware to apply different JSON parser configurations
 based on route
- Applied 500kb limit specifically for transcription conversion endpoints
- Maintained default limits for all other routes to preserve security

Technical notes:
- Could not find a built-in Express solution to specify parser config per route
- Custom middleware conditionally applies the appropriate parser configuration
---
 CHANGELOG.md                                  |  1 +
 .../y-provider/__tests__/server.test.ts       | 32 +++++++++++++++++++
 .../y-provider/src/servers/appServer.ts       |  8 ++++-
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d70ef583..1b0a03a3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@ and this project adheres to
 - ✅(frontend) Improve tests coverage
 - ⬆️(docker) upgrade backend image to python 3.13 #973
 - ⬆️(docker) upgrade node images to alpine 3.21
+- 🐛(y-provider) increase JSON size limits for transcription conversion
 
 
 ### Removed
diff --git a/src/frontend/servers/y-provider/__tests__/server.test.ts b/src/frontend/servers/y-provider/__tests__/server.test.ts
index 2f048bff..0c4ed30a 100644
--- a/src/frontend/servers/y-provider/__tests__/server.test.ts
+++ b/src/frontend/servers/y-provider/__tests__/server.test.ts
@@ -1,5 +1,7 @@
 import request from 'supertest';
 
+import { routes } from '@/routes';
+
 const port = 5557;
 const origin = 'http://localhost:3000';
 
@@ -36,4 +38,34 @@ describe('Server Tests', () => {
       expect(response.body.error).toBe('Forbidden');
     });
   });
+
+  it('should allow JSON payloads up to 500kb for the CONVERT_MARKDOWN route', async () => {
+    const largePayload = 'a'.repeat(400 * 1024); // 400kb payload
+    const response = await request(app)
+      .post(routes.CONVERT_MARKDOWN)
+      .send({ data: largePayload })
+      .set('Content-Type', 'application/json');
+
+    expect(response.status).not.toBe(413);
+  });
+
+  it('should reject JSON payloads larger than 500kb for the CONVERT_MARKDOWN route', async () => {
+    const oversizedPayload = 'a'.repeat(501 * 1024); // 501kb payload
+    const response = await request(app)
+      .post(routes.CONVERT_MARKDOWN)
+      .send({ data: oversizedPayload })
+      .set('Content-Type', 'application/json');
+
+    expect(response.status).toBe(413);
+  });
+
+  it('should use the default JSON limit for other routes', async () => {
+    const largePayload = 'a'.repeat(150 * 1024);
+    const response = await request(app)
+      .post('/some-other-route')
+      .send({ data: largePayload })
+      .set('Content-Type', 'application/json');
+
+    expect(response.status).toBe(413);
+  });
 });
diff --git a/src/frontend/servers/y-provider/src/servers/appServer.ts b/src/frontend/servers/y-provider/src/servers/appServer.ts
index 00532e03..5c035db7 100644
--- a/src/frontend/servers/y-provider/src/servers/appServer.ts
+++ b/src/frontend/servers/y-provider/src/servers/appServer.ts
@@ -21,7 +21,13 @@ import { logger } from '../utils';
  */
 export const initServer = () => {
   const { app } = expressWebsockets(express());
-  app.use(express.json());
+  app.use((req, res, next) => {
+    if (req.path === routes.CONVERT_MARKDOWN) {
+      // Large transcript files are bigger than the default '100kb' limit
+      return express.json({ limit: '500kb' })(req, res, next);
+    }
+    express.json()(req, res, next);
+  });
   app.use(corsMiddleware);
 
   /**