From 19c8b86ff83c2fe8e966d4bd62518ce47b39e951 Mon Sep 17 00:00:00 2001
From: Alice Gaudon <alice@gaudon.pro>
Date: Sun, 24 Jan 2021 16:35:33 +0100
Subject: [PATCH] Fix express body parsing middlewares corrupting
 AsyncLocalStorage

Closes #17
---
 src/Logger.ts                         | 13 +++++++++++++
 src/components/ExpressAppComponent.ts | 10 +++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/Logger.ts b/src/Logger.ts
index f970913..05ceee6 100644
--- a/src/Logger.ts
+++ b/src/Logger.ts
@@ -25,3 +25,16 @@ export const loggingContextMiddleware: RequestHandler = (req, res, next) => {
         next();
     });
 };
+
+export const preventContextCorruptionMiddleware = (delegate: RequestHandler): RequestHandler => (
+    req,
+    res,
+    next,
+) => {
+    const data = requestIdStorage.getStore() as string;
+
+    delegate(req, res, (err?: Error | 'router') => {
+        requestIdStorage.enterWith(data);
+        next(err);
+    });
+};
diff --git a/src/components/ExpressAppComponent.ts b/src/components/ExpressAppComponent.ts
index 47ba393..5ab489a 100644
--- a/src/components/ExpressAppComponent.ts
+++ b/src/components/ExpressAppComponent.ts
@@ -1,6 +1,6 @@
 import ApplicationComponent from "../ApplicationComponent";
 import express, {Express, Router} from "express";
-import {logger} from "../Logger";
+import {logger, preventContextCorruptionMiddleware} from "../Logger";
 import {Server} from "http";
 import compression from "compression";
 import Middleware from "../Middleware";
@@ -30,12 +30,12 @@ export default class ExpressAppComponent extends ApplicationComponent {
     }
 
     public async init(router: Router): Promise<void> {
-        router.use(express.json({
+        router.use(preventContextCorruptionMiddleware(express.json({
             type: req => req.headers['content-type']?.match(/^application\/(.+\+)?json$/),
-        }));
-        router.use(express.urlencoded({
+        })));
+        router.use(preventContextCorruptionMiddleware(express.urlencoded({
             extended: true,
-        }));
+        })));
 
         // gzip
         router.use(compression());