From 3ac27117c64cc720334e50a8b15eb4b8467cfe90 Mon Sep 17 00:00:00 2001
From: mknichel <7355009+mknichel@users.noreply.github.com>
Date: Thu, 16 Nov 2023 13:36:00 -0800
Subject: [PATCH] [.next/trace] Record start-dev-server trace span (#58469)

This PR makes sure that the `start-dev-server` trace span is recorded to the `.next/trace` file and uploaded to the telemetry endpoint when opted in.

Before this PR, the `start-dev-server` span was recorded in `next-dev` in the CLI. However, this would never be written to the `.next/trace` file since it happens in a different process (not the child process for next server). After this PR, the trace span happens in the next-server child process and will be recorded in the `.next/trace` file along with the other events produced by the dev server.
---
 packages/next/src/cli/next-dev.ts            | 5 +----
 packages/next/src/server/lib/start-server.ts | 5 ++++-
 packages/next/src/trace/trace-uploader.ts    | 1 +
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/packages/next/src/cli/next-dev.ts b/packages/next/src/cli/next-dev.ts
index bdae5f6248..78831fdfae 100644
--- a/packages/next/src/cli/next-dev.ts
+++ b/packages/next/src/cli/next-dev.ts
@@ -27,7 +27,6 @@ import { createSelfSignedCertificate } from '../lib/mkcert'
 import type { SelfSignedCertificate } from '../lib/mkcert'
 import uploadTrace from '../trace/upload-trace'
 import { initialEnv } from '@next/env'
-import { trace } from '../trace'
 import { fork } from 'child_process'
 import {
   getReservedPortExplanation,
@@ -318,9 +317,7 @@ const nextDev: CliCommand = async (args) => {
     }
   }
 
-  await trace('start-dev-server').traceAsyncFn(async (_) => {
-    await runDevServer(false)
-  })
+  await runDevServer(false)
 }
 
 function cleanup() {
diff --git a/packages/next/src/server/lib/start-server.ts b/packages/next/src/server/lib/start-server.ts
index 9e6057d14c..288705e0c9 100644
--- a/packages/next/src/server/lib/start-server.ts
+++ b/packages/next/src/server/lib/start-server.ts
@@ -22,6 +22,7 @@ import { initialize } from './router-server'
 import { CONFIG_FILES } from '../../shared/lib/constants'
 import { getStartServerInfo, logStartInfo } from './app-info-log'
 import { validateTurboNextConfig } from '../../lib/turbopack-warning'
+import { trace } from '../../trace'
 import { isPostpone } from './router-utils/is-postpone'
 
 const debug = setupDebug('next:start-server')
@@ -361,7 +362,9 @@ export async function startServer(
 if (process.env.NEXT_PRIVATE_WORKER && process.send) {
   process.addListener('message', async (msg: any) => {
     if (msg && typeof msg && msg.nextWorkerOptions && process.send) {
-      await startServer(msg.nextWorkerOptions)
+      await trace('start-dev-server').traceAsyncFn(() =>
+        startServer(msg.nextWorkerOptions)
+      )
       process.send({ nextServerReady: true })
     }
   })
diff --git a/packages/next/src/trace/trace-uploader.ts b/packages/next/src/trace/trace-uploader.ts
index 04158097b1..2ddf470c34 100644
--- a/packages/next/src/trace/trace-uploader.ts
+++ b/packages/next/src/trace/trace-uploader.ts
@@ -18,6 +18,7 @@ const EVENT_FILTER = new Set([
   'webpack-invalid-client',
   'webpack-invalidated-server',
   'navigation-to-hydration',
+  'start-dev-server',
 ])
 
 const {