Fix Next.js getServerSideProps error handling (#2971)

Author: Stephen Belanger

packages/datadog-plugin-next/src/index.js

@@ -68,6 +68,12 @@ class NextPlugin extends Plugin {
       const span = store.span
       const req = this._requests.get(span)
 
+      // Only use error page names if there's not already a name
+      const current = span.context()._tags['next.page']
+      if (current && (page === '/404' || page === '/500' || page === '/_error')) {
+        return
+      }
+
       span.addTags({
         [COMPONENT]: this.constructor.id,
         'resource.name': `${req.method} ${page}`.trim(),

packages/datadog-plugin-next/test/index.spec.js

@@ -7,6 +7,7 @@ const getPort = require('get-port')
 const { execSync, spawn } = require('child_process')
 const agent = require('../../dd-trace/test/plugins/agent')
 const { writeFileSync } = require('fs')
+const { satisfies } = require('semver')
 
 describe('Plugin', function () {
   let server
@@ -209,25 +210,28 @@ describe('Plugin', function () {
               .catch(done)
           })
 
+          const pkg = require(`${__dirname}/../../../versions/next@${version}/node_modules/next/package.json`)
+
           const pathTests = [
             ['/hello', '/hello'],
             ['/hello/world', '/hello/[name]'],
-            ['/hello/other', '/hello/other']
+            ['/hello/other', '/hello/other'],
+            ['/error/not_found', '/error/not_found', satisfies(pkg.version, '>=11') ? 404 : 500],
+            ['/error/get_server_side_props', '/error/get_server_side_props', 500]
           ]
-          pathTests.forEach(([url, expectedPath]) => {
+          pathTests.forEach(([url, expectedPath, statusCode]) => {
             it(`should infer the corrrect resource (${expectedPath})`, done => {
               agent
                 .use(traces => {
                   const spans = traces[0]
 
                   expect(spans[0]).to.have.property('resource', `GET ${expectedPath}`)
+                  expect(spans[0].meta).to.have.property('http.status_code', `${statusCode || 200}`)
                 })
                 .then(done)
                 .catch(done)
 
-              axios
-                .get(`http://localhost:${port}${url}`)
-                .catch(done)
+              axios.get(`http://localhost:${port}${url}`)
             })
           })
 
@@ -285,7 +289,7 @@ describe('Plugin', function () {
               .catch(done)
 
             axios
-              .get(`http://localhost:${port}/boom`)
+              .get(`http://localhost:${port}/api/error/boom`)
               .catch((response) => {
                 expect(response.statusCode).to.eql(500)
               })

packages/datadog-plugin-next/test/pages/error/get_server_side_props.js

@@ -0,0 +1,11 @@
+export async function getServerSideProps (ctx) {
+  throw new Error('fail')
+}
+
+export default function GetServerSideProps () {
+  return (
+    <div>
+      Get Server Side Props!
+    </div>
+  )
+}

packages/datadog-plugin-next/test/pages/error/not_found.js

@@ -0,0 +1,13 @@
+export async function getServerSideProps (ctx) {
+  return {
+    notFound: true
+  }
+}
+
+export default function NotFound () {
+  return (
+    <div>
+      Not found!
+    </div>
+  )
+}