Turbopack: Remove the deprecated .turbo config object (#84109)

This config name was previously deprecated in a 15.x release (renamed to `turbopack`), and there's already a codemod to migrate these over.

Author: bgw

docs/01-app/03-api-reference/08-turbopack.mdx

@@ -188,8 +188,6 @@ Turbopack can be configured via `next.config.js` (or `next.config.ts`) under the
   Change or extend file extensions for module resolution.
 - **`moduleIds`**
   Set how module IDs are generated (`'named'` vs `'deterministic'`).
-- **`memoryLimit`**
-  Set a memory limit (in bytes) for Turbopack.
 
 ```js filename="next.config.js"
 module.exports = {

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

@@ -8,7 +8,6 @@ import type { SizeLimit } from '../types'
 import type {
   ExportPathMap,
   TurbopackLoaderItem,
-  DeprecatedExperimentalTurboOptions,
   TurbopackOptions,
   TurbopackRuleConfigItem,
   TurbopackRuleConfigCollection,
@@ -163,32 +162,6 @@ const zTurbopackConfig: zod.ZodType<TurbopackOptions> = z.strictObject({
   root: z.string().optional(),
 })
 
-// Same as zTurbopackConfig but with deprecated properties. Unfortunately, base
-// properties are duplicated here as `ZodType`s do not export `extend()`.
-const zDeprecatedExperimentalTurboConfig: zod.ZodType<DeprecatedExperimentalTurboOptions> =
-  z.strictObject({
-    loaders: z.record(z.string(), z.array(zTurbopackLoaderItem)).optional(),
-    rules: z.record(z.string(), zTurbopackRuleConfigCollection).optional(),
-    resolveAlias: z
-      .record(
-        z.string(),
-        z.union([
-          z.string(),
-          z.array(z.string()),
-          z.record(z.string(), z.union([z.string(), z.array(z.string())])),
-        ])
-      )
-      .optional(),
-    resolveExtensions: z.array(z.string()).optional(),
-    treeShaking: z.boolean().optional(),
-    persistentCaching: z.union([z.number(), z.literal(false)]).optional(),
-    memoryLimit: z.number().optional(),
-    moduleIds: z.enum(['named', 'deterministic']).optional(),
-    minify: z.boolean().optional(),
-    sourceMaps: z.boolean().optional(),
-    root: z.string().optional(),
-  })
-
 export const configSchema: zod.ZodType<NextConfig> = z.lazy(() =>
   z.strictObject({
     allowedDevOrigins: z.array(z.string()).optional(),
@@ -462,10 +435,6 @@ export const configSchema: zod.ZodType<NextConfig> = z.lazy(() =>
         typedRoutes: z.boolean().optional(),
         webpackBuildWorker: z.boolean().optional(),
         webpackMemoryOptimizations: z.boolean().optional(),
-        /**
-         * @deprecated Use `config.turbopack` instead.
-         */
-        turbo: zDeprecatedExperimentalTurboConfig.optional(),
         turbopackMemoryLimit: z.number().optional(),
         turbopackMinify: z.boolean().optional(),
         turbopackPersistentCaching: z.boolean().optional(),

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

@@ -25,7 +25,7 @@ export type NextConfigComplete = Required<NextConfig> & {
   // override NextConfigComplete.experimental.htmlLimitedBots to string
   // because it's not defined in NextConfigComplete.experimental
   htmlLimitedBots: string | undefined
-  experimental: Omit<ExperimentalConfig, 'turbo'>
+  experimental: ExperimentalConfig
 }
 
 export type I18NDomains = readonly DomainLocale[]
@@ -182,40 +182,6 @@ export interface TurbopackOptions {
   root?: string
 }
 
-export interface DeprecatedExperimentalTurboOptions extends TurbopackOptions {
-  /**
-   * (`next --turbopack` only) A list of webpack loaders to apply when running with Turbopack.
-   *
-   * @deprecated Use `rules` instead.
-   * @see [Turbopack Loaders](https://nextjs.org/docs/app/api-reference/config/next-config-js/turbopack#configuring-webpack-loaders)
-   */
-  loaders?: Record<string, TurbopackLoaderItem[]>
-
-  /**
-   * A target memory limit for turbo, in bytes.
-   * @deprecated Use `experimental.turbopackMemoryLimit` instead.
-   */
-  memoryLimit?: number
-
-  /**
-   * Enable minification. Defaults to true in build mode and false in dev mode.
-   * @deprecated Use `experimental.turbopackMinify` instead.
-   */
-  minify?: boolean
-
-  /**
-   * Enable tree shaking for the turbopack dev server and build.
-   * @deprecated Use `experimental.turbopackTreeShaking` instead.
-   */
-  treeShaking?: boolean
-
-  /**
-   * Enable source maps. Defaults to true.
-   * @deprecated Use `experimental.turbopackSourceMaps` instead.
-   */
-  sourceMaps?: boolean
-}
-
 export interface WebpackConfigContext {
   /** Next.js root directory */
   dir: string
@@ -444,12 +410,6 @@ export interface ExperimentalConfig {
    */
   optimizeServerReact?: boolean
 
-  /**
-   * @deprecated Use `config.turbopack` instead.
-   * Run `npx @next/codemod@latest next-experimental-turbo-to-turbopack .` to migrate automatically.
-   */
-  turbo?: DeprecatedExperimentalTurboOptions
-
   /**
    * A target memory limit for turbo, in bytes.
    */
@@ -1487,7 +1447,6 @@ export const defaultConfig = Object.freeze({
     disablePostcssPresetEnv: undefined,
     amp: undefined,
     urlImports: undefined,
-    turbo: undefined,
     typedEnv: false,
     clientTraceMetadata: undefined,
     parallelServerCompiles: false,

packages/next/src/server/config.ts

@@ -16,7 +16,6 @@ import type {
   ExperimentalConfig,
   NextConfigComplete,
   NextConfig,
-  TurbopackLoaderItem,
 } from './config-shared'
 
 import { loadWebpackHook } from './config-utils'
@@ -1458,7 +1457,7 @@ export default async function loadConfig(
       ) as (keyof ExperimentalConfig)[]) {
         const value = loadedConfig.experimental[name]
 
-        if (name === 'turbo' && !process.env.TURBOPACK) {
+        if (name.startsWith('turbopack') && !process.env.TURBOPACK) {
           // Ignore any Turbopack config if Turbopack is not enabled
           continue
         }
@@ -1502,47 +1501,6 @@ export default async function loadConfig(
       userConfig.reactProductionProfiling = reactProductionProfiling
     }
 
-    if (
-      userConfig.experimental?.turbo?.loaders &&
-      !userConfig.experimental?.turbo?.rules
-    ) {
-      curLog.warn(
-        'experimental.turbo.loaders is now deprecated. Please update next.config.js to use experimental.turbo.rules as soon as possible.\n' +
-          'The new option is similar, but the key should be a glob instead of an extension.\n' +
-          'Example: loaders: { ".mdx": ["mdx-loader"] } -> rules: { "*.mdx": ["mdx-loader"] }" }\n' +
-          'See more info here https://nextjs.org/docs/app/api-reference/next-config-js/turbo'
-      )
-
-      const rules: Record<string, TurbopackLoaderItem[]> = {}
-      for (const [ext, loaders] of Object.entries(
-        userConfig.experimental.turbo.loaders
-      )) {
-        rules['*' + ext] = loaders as TurbopackLoaderItem[]
-      }
-
-      userConfig.experimental.turbo.rules = rules
-    }
-
-    if (userConfig.experimental?.turbo) {
-      curLog.warn(
-        'The config property `experimental.turbo` is deprecated. Move this setting to `config.turbopack` or run `npx @next/codemod@latest next-experimental-turbo-to-turbopack .`'
-      )
-
-      // Merge the two configs, preferring values in `config.turbopack`.
-      userConfig.turbopack = {
-        ...userConfig.experimental.turbo,
-        ...userConfig.turbopack,
-      }
-      userConfig.experimental.turbopackMemoryLimit ??=
-        userConfig.experimental.turbo.memoryLimit
-      userConfig.experimental.turbopackMinify ??=
-        userConfig.experimental.turbo.minify
-      userConfig.experimental.turbopackTreeShaking ??=
-        userConfig.experimental.turbo.treeShaking
-      userConfig.experimental.turbopackSourceMaps ??=
-        userConfig.experimental.turbo.sourceMaps
-    }
-
     if (userConfig.experimental?.useLightningcss) {
       const { loadBindings } =
         require('../build/swc') as typeof import('../build/swc')