Check next.config.js settings

packages/next/build/index.ts

@@ -50,8 +50,8 @@ import { normalizePagePath } from '../next-server/server/normalize-page-path'
 import {
   eventBuildCompleted,
   eventBuildOptimize,
+  eventCliSession,
   eventNextPlugins,
-  eventVersion,
 } from '../telemetry/events'
 import { Telemetry } from '../telemetry/storage'
 import { CompilerResult, runCompiler } from './compiler'
@@ -161,7 +161,7 @@ export default async function build(dir: string, conf = null): Promise<void> {
   let hasPublicDir = false
 
   telemetry.record(
-    eventVersion({
+    eventCliSession(PHASE_PRODUCTION_BUILD, dir, {
       cliCommand: 'build',
       isSrcDir: path.relative(dir, pagesDir!).startsWith('src'),
       hasNowJson: !!(await findUp('now.json', { cwd: dir })),

packages/next/export/index.ts

@@ -31,7 +31,7 @@ import {
 import loadConfig, {
   isTargetLikeServerless,
 } from '../next-server/server/config'
-import { eventVersion } from '../telemetry/events'
+import { eventCliSession } from '../telemetry/events'
 import { Telemetry } from '../telemetry/storage'
 import { normalizePagePath } from '../next-server/server/normalize-page-path'
 
@@ -105,7 +105,7 @@ export default async function(
 
   if (telemetry) {
     telemetry.record(
-      eventVersion({
+      eventCliSession(PHASE_EXPORT, distDir, {
         cliCommand: 'export',
         isSrcDir: null,
         hasNowJson: !!(await findUp('now.json', { cwd: dir })),

packages/next/next-server/server/config.ts

@@ -198,7 +198,7 @@ function assignDefaults(userConfig: { [key: string]: any }) {
   return result
 }
 
-function normalizeConfig(phase: string, config: any) {
+export function normalizeConfig(phase: string, config: any) {
   if (typeof config === 'function') {
     config = config(phase, { defaultConfig })
 

packages/next/server/next-dev-server.ts

@@ -25,7 +25,7 @@ import { __ApiPreviewProps } from '../next-server/server/api-utils'
 import Server, { ServerConstructor } from '../next-server/server/next-server'
 import { normalizePagePath } from '../next-server/server/normalize-page-path'
 import Router, { Params, route } from '../next-server/server/router'
-import { eventVersion } from '../telemetry/events'
+import { eventCliSession } from '../telemetry/events'
 import { Telemetry } from '../telemetry/storage'
 import ErrorDebug from './error-debug'
 import HotReloader from './hot-reloader'
@@ -233,7 +233,7 @@ export default class DevServer extends Server {
 
     const telemetry = new Telemetry({ distDir: this.distDir })
     telemetry.record(
-      eventVersion({
+      eventCliSession(PHASE_DEVELOPMENT_SERVER, this.distDir, {
         cliCommand: 'dev',
         isSrcDir: relative(this.dir, this.pagesDir!).startsWith('src'),
         hasNowJson: !!(await findUp('now.json', { cwd: this.dir })),

packages/next/telemetry/events/version.ts

@@ -1,3 +1,13 @@
+import findUp from 'find-up'
+import path from 'path'
+import {
+  CONFIG_FILE,
+  PHASE_DEVELOPMENT_SERVER,
+  PHASE_EXPORT,
+  PHASE_PRODUCTION_BUILD,
+} from '../../next-server/lib/constants'
+import { normalizeConfig } from '../../next-server/server/config'
+
 const EVENT_VERSION = 'NEXT_CLI_SESSION_STARTED'
 
 type EventCliSessionStarted = {
@@ -7,27 +17,92 @@ type EventCliSessionStarted = {
   isSrcDir: boolean | null
   hasNowJson: boolean
   isCustomServer: boolean | null
+  hasNextConfig: boolean
+  buildTarget: string
+  hasWebpackConfig: boolean
+  hasBabelConfig: boolean
+}
+
+function hasBabelConfig(dir: string): boolean {
+  try {
+    const noopFile = path.join(dir, 'noop.js')
+    const res = require('@babel/core').loadPartialConfig({
+      cwd: dir,
+      filename: noopFile,
+      sourceFileName: noopFile,
+    }) as any
+    const isForTooling =
+      res.options?.presets?.every(
+        (e: any) => e?.file?.request === 'next/babel'
+      ) && res.options?.plugins?.length === 0
+    return res.hasFilesystemConfig() && !isForTooling
+  } catch {
+    return false
+  }
+}
+
+type NextConfigurationPhase =
+  | typeof PHASE_DEVELOPMENT_SERVER
+  | typeof PHASE_PRODUCTION_BUILD
+  | typeof PHASE_EXPORT
+
+function getNextConfig(
+  phase: NextConfigurationPhase,
+  dir: string
+): { [key: string]: any } | null {
+  try {
+    const configurationPath = findUp.sync(CONFIG_FILE, {
+      cwd: dir,
+    })
+
+    if (configurationPath) {
+      // This should've already been loaded, and thus should be cached / won't
+      // be re-evaluated.
+      const configurationModule = require(configurationPath)
+
+      // Re-normalize the configuration.
+      return normalizeConfig(
+        phase,
+        configurationModule.default || configurationModule
+      )
+    }
+  } catch {
+    // ignored
+  }
+  return null
 }
 
-export function eventVersion(
-  event: Omit<EventCliSessionStarted, 'nextVersion' | 'nodeVersion'>
+export function eventCliSession(
+  phase: NextConfigurationPhase,
+  dir: string,
+  event: Omit<
+    EventCliSessionStarted,
+    | 'nextVersion'
+    | 'nodeVersion'
+    | 'hasNextConfig'
+    | 'buildTarget'
+    | 'hasWebpackConfig'
+    | 'hasBabelConfig'
+  >
 ): { eventName: string; payload: EventCliSessionStarted }[] {
   // This should be an invariant, if it fails our build tooling is broken.
   if (typeof process.env.__NEXT_VERSION !== 'string') {
     return []
   }
 
-  return [
-    {
-      eventName: EVENT_VERSION,
-      payload: {
-        nextVersion: process.env.__NEXT_VERSION,
-        nodeVersion: process.version,
-        cliCommand: event.cliCommand,
-        isSrcDir: event.isSrcDir,
-        hasNowJson: event.hasNowJson,
-        isCustomServer: event.isCustomServer,
-      } as EventCliSessionStarted,
-    },
-  ]
+  const userConfiguration = getNextConfig(phase, dir)
+
+  const payload: EventCliSessionStarted = {
+    nextVersion: process.env.__NEXT_VERSION,
+    nodeVersion: process.version,
+    cliCommand: event.cliCommand,
+    isSrcDir: event.isSrcDir,
+    hasNowJson: event.hasNowJson,
+    isCustomServer: event.isCustomServer,
+    hasNextConfig: !!userConfiguration,
+    buildTarget: userConfiguration?.target ?? 'default',
+    hasWebpackConfig: typeof userConfiguration?.webpack === 'function',
+    hasBabelConfig: hasBabelConfig(dir),
+  }
+  return [{ eventName: EVENT_VERSION, payload }]
 }

test/integration/telemetry/.babelrc.default

@@ -0,0 +1,3 @@
+{
+  "presets": ["next/babel"]
+}

test/integration/telemetry/.babelrc.plugin

@@ -0,0 +1,4 @@
+{
+  "presets": ["next/babel"],
+  "plugins": ["@babel/plugin-proposal-object-rest-spread"]
+}

test/integration/telemetry/.babelrc.preset

@@ -0,0 +1,3 @@
+{
+  "presets": ["next/babel", "@babel/preset-flow"]
+}

test/integration/telemetry/next.config.target

@@ -0,0 +1,10 @@
+const { PHASE_PRODUCTION_BUILD } = require('next/constants')
+
+module.exports = phase => {
+  if (phase === PHASE_PRODUCTION_BUILD) {
+    return {
+      target: 'experimental-serverless-trace',
+    }
+  }
+  return {}
+}

test/integration/telemetry/next.config.webpack

@@ -0,0 +1,5 @@
+module.exports = {
+  webpack(config) {
+    return config
+  },
+}

test/integration/telemetry/package.babel

@@ -0,0 +1,10 @@
+{
+  "babel": {
+    "presets": [
+      "next/babel"
+    ],
+    "plugins": [
+      "@babel/plugin-proposal-object-rest-spread"
+    ]
+  }
+}