From 6ae58175293e63daf5c9af76c293392713f5bd21 Mon Sep 17 00:00:00 2001
From: Jerko Steiner <jerko.steiner@gmail.com>
Date: Tue, 19 Mar 2019 10:20:32 +0500
Subject: [PATCH] Generate req.correlationId

---
 packages/server/@types/express.d.ts                |  1 +
 packages/server/src/middleware/ErrorApiHandler.ts  |  3 ++-
 packages/server/src/middleware/ErrorPageHandler.ts |  4 +++-
 packages/server/src/middleware/RequestLogger.ts    | 10 ++++++----
 packages/server/src/middleware/Transaction.ts      |  3 ++-
 5 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/packages/server/@types/express.d.ts b/packages/server/@types/express.d.ts
index 5083330..a91e2f3 100644
--- a/packages/server/@types/express.d.ts
+++ b/packages/server/@types/express.d.ts
@@ -9,6 +9,7 @@ declare namespace Application {
 
 declare namespace Express {
   export interface Request {
+    correlationId: string
     user?: Application.User
     logInPromise(user: any): Promise<void>
   }
diff --git a/packages/server/src/middleware/ErrorApiHandler.ts b/packages/server/src/middleware/ErrorApiHandler.ts
index b2289a3..48ce70f 100644
--- a/packages/server/src/middleware/ErrorApiHandler.ts
+++ b/packages/server/src/middleware/ErrorApiHandler.ts
@@ -6,7 +6,8 @@ export class ErrorApiHandler implements IMiddleware {
   constructor(readonly logger: ILogger) {}
 
   handle: IErrorHandler = (err, req, res, next) => {
-    this.logger.error('An API error occurred: %s', err.stack)
+    this.logger.error('%s An API error occurred: %s',
+      req.correlationId, err.stack)
     const statusCode = this.getStatus(err)
     res.status(statusCode)
     res.end('An error occurred')
diff --git a/packages/server/src/middleware/ErrorPageHandler.ts b/packages/server/src/middleware/ErrorPageHandler.ts
index e007b65..4652171 100644
--- a/packages/server/src/middleware/ErrorPageHandler.ts
+++ b/packages/server/src/middleware/ErrorPageHandler.ts
@@ -6,7 +6,9 @@ export class ErrorPageHandler implements IMiddleware {
   constructor(readonly logger: ILogger) {}
 
   handle: IErrorHandler = (err, req, res, next) => {
-    this.logger.error('An error occurred: %s', err.stack)
+    this.logger.error(
+      '%s An error occurred: %s',
+      req.correlationId, err.stack)
     // TODO Show an error page!
     const statusCode = this.getStatus(err)
     res.status(statusCode)
diff --git a/packages/server/src/middleware/RequestLogger.ts b/packages/server/src/middleware/RequestLogger.ts
index 98d3fcd..72623f6 100644
--- a/packages/server/src/middleware/RequestLogger.ts
+++ b/packages/server/src/middleware/RequestLogger.ts
@@ -1,21 +1,23 @@
 import {IHandler} from './IHandler'
 import {ILogger} from '../logger/ILogger'
 import {IMiddleware} from './IMiddleware'
+import shortid from 'shortid'
 
 export class RequestLogger implements IMiddleware {
   constructor(protected readonly logger: ILogger) {}
 
   handle: IHandler = (req, res, next) => {
     const start = Date.now()
+    req.correlationId = shortid.generate()
     res.on('finish', () => {
       const { method, originalUrl, user } = req
       const username = user ? user.username : ''
       const duration = Date.now() - start
-      this.logger.debug('%s %s [%s] %j',
-        method, originalUrl, username, req.body)
+      this.logger.debug('%s %s %s [%s] %j',
+        req.correlationId, method, originalUrl, username, req.body)
       const { statusCode } = res
-      this.logger.info('%s %s [%s] %d %sms',
-        method, originalUrl, username, statusCode, duration)
+      this.logger.info('%s %s %s [%s] %d %sms',
+        req.correlationId, method, originalUrl, username, statusCode, duration)
     })
     next()
   }
diff --git a/packages/server/src/middleware/Transaction.ts b/packages/server/src/middleware/Transaction.ts
index 92f7bff..6982e27 100644
--- a/packages/server/src/middleware/Transaction.ts
+++ b/packages/server/src/middleware/Transaction.ts
@@ -14,7 +14,8 @@ export class Transaction implements IMiddleware {
     ns.bindEmitter(res)
 
     ns.run(() => {
-      const correlationId = shortid.generate();
+      // use pregenerated request correlationId
+      const correlationId = req.correlationId || shortid.generate();
       (req as any).correlationId = correlationId
       ns.set(CORRELATION_ID, correlationId)
       next()