fix: honour 'usePathAsTransactionName' config var in Next.js instrumentation

Fixes: #3072

Author: trentm

CHANGELOG.asciidoc

@@ -32,6 +32,26 @@ Notes:
 === Node.js Agent version 3.x
 
 
+==== Unreleased
+
+[float]
+===== Breaking changes
+
+[float]
+===== Features
+
+[float]
+===== Bug fixes
+
+* Fix Next.js instrumentation to honour the <<use-path-as-transaction-name>>
+  config setting. When set to true the APM transaction name for a request to a
+  Next.js Dynamic Route will use the request path, e.g. `GET /about-us`, rather
+  than the dynamic route name, e.g. `GET /[...page]`. ({issues}3072[#3072])
+
+[float]
+===== Chores
+
+
 [[release-notes-3.41.0]]
 ==== 3.41.0 2022/12/12
 

examples/nextjs/package.json

@@ -9,7 +9,7 @@
     "lint": "next lint"
   },
   "dependencies": {
-    "elastic-apm-node": "elastic/apm-agent-nodejs#main",
+    "elastic-apm-node": "^3.40.1",
     "next": "12.3.1",
     "react": "18.2.0",
     "react-dom": "18.2.0"

lib/instrumentation/modules/next/dist/server/dev/next-dev-server.js

@@ -143,7 +143,11 @@ module.exports = function (mod, agent, { version, enabled }) {
       // specific route wrapper hasn't already done so.
       if (trans && !trans[kSetTransNameFn]) {
         trans[kSetTransNameFn] = (req, pathname) => {
-          trans.setDefaultName(`${req.method} ${pathname}`)
+          if (agent._conf.usePathAsTransactionName) {
+            trans.setDefaultName(`${req.method} ${req.url}`)
+          } else {
+            trans.setDefaultName(`${req.method} ${pathname}`)
+          }
           // Ensure only the first `findPageComponents` result sets the trans
           // name, otherwise a loaded `/_error` for page error handling could
           // incorrectly override.

lib/instrumentation/modules/next/dist/server/next-server.js

@@ -140,7 +140,11 @@ module.exports = function (mod, agent, { version, enabled }) {
       // specific route wrapper hasn't already done so.
       if (trans && !trans[kSetTransNameFn]) {
         trans[kSetTransNameFn] = (req, pathname) => {
-          trans.setDefaultName(`${req.method} ${pathname}`)
+          if (agent._conf.usePathAsTransactionName) {
+            trans.setDefaultName(`${req.method} ${req.url}`)
+          } else {
+            trans.setDefaultName(`${req.method} ${pathname}`)
+          }
           // Ensure only the first `findPageComponents` result sets the trans
           // name, otherwise a loaded `/_error` for page error handling could
           // incorrectly override.