fix(turbopack): middleware path and aliases (#56804)

### Description - Adds the page path to the middleware template (and also uses the template from the next.js loader) - ESM aliases for the edge context - Fix for the process polyfill to make it possible to import from `dist/esm` - Fix for the `server-only`/`client-only` aliases Closes WEB-1779
vercel · Oct 13, 2023 · f9d12d1 · f9d12d1
1 parent fe0bfbf
commit f9d12d1
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Showing 6 changed files with 113 additions and 40 deletions.
diff --git a/packages/next-swc/crates/next-core/src/middleware.rs b/packages/next-swc/crates/next-core/src/middleware.rs
@@ -36,6 +36,7 @@ pub async fn get_middleware_module(
         project_root,
         indexmap! {
             "VAR_USERLAND" => INNER.to_string(),
+            "VAR_DEFINITION_PAGE" => "/middleware".to_string(),
         },
         indexmap! {},
     )

diff --git a/packages/next-swc/crates/next-core/src/next_import_map.rs b/packages/next-swc/crates/next-core/src/next_import_map.rs
@@ -365,6 +365,52 @@ pub async fn get_next_edge_import_map(
 ) -> Result<Vc<ImportMap>> {
     let mut import_map = ImportMap::empty();
 
+    // /~https://github.com/vercel/next.js/blob/786ef25e529e1fb2dda398aebd02ccbc8d0fb673/packages/next/src/build/webpack-config.ts#L815-L861
+
+    // Alias next/dist imports to next/dist/esm assets
+    insert_wildcard_alias_map(
+        &mut import_map,
+        project_path,
+        indexmap! {
+            "next/dist/build/" => "next/dist/esm/build/*".to_string(),
+            "next/dist/client/" => "next/dist/esm/client/*".to_string(),
+            "next/dist/shared/" => "next/dist/esm/shared/*".to_string(),
+            "next/dist/pages/" => "next/dist/esm/pages/*".to_string(),
+            "next/dist/lib/" => "next/dist/esm/lib/*".to_string(),
+            "next/dist/server/" => "next/dist/esm/server/*".to_string(),
+        },
+    );
+
+    // Alias the usage of next public APIs
+    insert_exact_alias_map(
+        &mut import_map,
+        project_path,
+        indexmap! {
+            "next/app" => "next/dist/esm/pages/_app".to_string(),
+            "next/document" => "next/dist/esm/pages/_document".to_string(),
+            "next/dynamic" => "next/dist/esm/shared/lib/dynamic".to_string(),
+            "next/head" => "next/dist/esm/shared/lib/head".to_string(),
+            "next/headers" => "next/dist/esm/client/components/headers".to_string(),
+            "next/image" => "next/dist/esm/shared/lib/image-external".to_string(),
+            "next/link" => "next/dist/esm/client/link".to_string(),
+            "next/navigation" => "next/dist/esm/client/components/navigation".to_string(),
+            "next/router" => "next/dist/esm/client/router".to_string(),
+            "next/script" => "next/dist/esm/client/script".to_string(),
+            "next/server" => "next/dist/esm/server/web/exports/index".to_string(),
+
+            "next/dist/client/components/headers" => "next/dist/esm/client/components/headers".to_string(),
+            "next/dist/client/components/navigation" => "next/dist/esm/client/components/navigation".to_string(),
+            "next/dist/client/link" => "next/dist/esm/client/link".to_string(),
+            "next/dist/client/router" => "next/dist/esm/client/router".to_string(),
+            "next/dist/client/script" => "next/dist/esm/client/script".to_string(),
+            "next/dist/pages/_app" => "next/dist/esm/pages/_app".to_string(),
+            "next/dist/pages/_document" => "next/dist/esm/pages/_document".to_string(),
+            "next/dist/shared/lib/dynamic" => "next/dist/esm/shared/lib/dynamic".to_string(),
+            "next/dist/shared/lib/head" => "next/dist/esm/shared/lib/head".to_string(),
+            "next/dist/shared/lib/image-external" => "next/dist/esm/shared/lib/image-external".to_string(),
+        },
+    );
+
     insert_next_shared_aliases(
         &mut import_map,
         project_path,
@@ -828,17 +874,41 @@ async fn insert_next_server_special_aliases(
     }
 
     // see /~https://github.com/vercel/next.js/blob/8013ef7372fc545d49dbd060461224ceb563b454/packages/next/src/build/webpack-config.ts#L1449-L1531
-    insert_exact_alias_map(
-        import_map,
-        project_path,
-        indexmap! {
-            "server-only" => "next/dist/compiled/server-only/empty".to_string(),
-            "client-only" => "next/dist/compiled/client-only/index".to_string(),
-            "next/dist/compiled/server-only" => "next/dist/compiled/server-only/empty".to_string(),
-            "next/dist/compiled/client-only" => "next/dist/compiled/client-only/index".to_string(),
-        },
-    );
+    match ty {
+        ServerContextType::Pages { .. }
+        | ServerContextType::PagesData { .. }
+        | ServerContextType::AppSSR { .. } => {
+            insert_exact_alias_map(
+                import_map,
+                project_path,
+                indexmap! {
+                    "server-only" => "next/dist/compiled/server-only/index".to_string(),
+                    "client-only" => "next/dist/compiled/client-only/index".to_string(),
+                    "next/dist/compiled/server-only" => "next/dist/compiled/server-only/index".to_string(),
+                    "next/dist/compiled/client-only" => "next/dist/compiled/client-only/index".to_string(),
+                },
+            );
+        }
+        // TODO: should include `ServerContextType::PagesApi` routes, but that type doesn't exist.
+        ServerContextType::AppRSC { .. }
+        | ServerContextType::AppRoute { .. }
+        | ServerContextType::Middleware => {
+            insert_exact_alias_map(
+                import_map,
+                project_path,
+                indexmap! {
+                    "server-only" => "next/dist/compiled/server-only/empty".to_string(),
+                    "client-only" => "next/dist/compiled/client-only/error".to_string(),
+                    "next/dist/compiled/server-only" => "next/dist/compiled/server-only/empty".to_string(),
+                    "next/dist/compiled/client-only" => "next/dist/compiled/client-only/error".to_string(),
+                },
+            );
+        }
+    }
 
+    // Potential the bundle introduced into middleware and api can be poisoned by
+    // client-only but not being used, so we disabled the `client-only` erroring
+    // on these layers. `server-only` is still available.
     if ty == ServerContextType::Middleware {
         insert_exact_alias_map(
             import_map,
@@ -1054,6 +1124,17 @@ fn insert_exact_alias_map(
     }
 }
 
+fn insert_wildcard_alias_map(
+    import_map: &mut ImportMap,
+    project_path: Vc<FileSystemPath>,
+    map: IndexMap<&'static str, String>,
+) {
+    for (pattern, request) in map {
+        import_map
+            .insert_wildcard_alias(pattern, request_to_import_mapping(project_path, &request));
+    }
+}
+
 /// Inserts an alias to an alternative of import mappings into an import map.
 fn insert_alias_to_alternatives<'a>(
     import_map: &mut ImportMap,

diff --git a/packages/next/src/build/load-entrypoint.ts b/packages/next/src/build/load-entrypoint.ts
@@ -26,11 +26,12 @@ const TEMPLATES_ESM_FOLDER = path.normalize(
 
 export async function loadEntrypoint(
   entrypoint:
-    | 'pages'
-    | 'pages-api'
     | 'app-page'
     | 'app-route'
-    | 'edge-app-route',
+    | 'edge-app-route'
+    | 'middleware'
+    | 'pages'
+    | 'pages-api',
   replacements: Record<`VAR_${string}`, string>,
   injections?: Record<string, string>
 ): Promise<string> {

diff --git a/packages/next/src/build/polyfills/process.ts b/packages/next/src/build/polyfills/process.ts
@@ -1,4 +1,4 @@
 module.exports =
   global.process?.env && typeof global.process?.env === 'object'
     ? global.process
-    : require('../../compiled/process')
+    : require('next/dist/compiled/process')
diff --git a/packages/next/src/build/templates/middleware.ts b/packages/next/src/build/templates/middleware.ts
@@ -10,18 +10,20 @@ import * as _mod from 'VAR_USERLAND'
 const mod = { ..._mod }
 const handler = mod.middleware || mod.default
 
+const page = 'VAR_DEFINITION_PAGE'
+
 if (typeof handler !== 'function') {
   throw new Error(
-    `The Middleware must export a \`middleware\` or a \`default\` function`
+    `The Middleware "${page}" must export a \`middleware\` or a \`default\` function`
   )
 }
 
-export default function (
+export default function nHandler(
   opts: Omit<AdapterOptions, 'IncrementalCache' | 'page' | 'handler'>
 ) {
   return adapter({
     ...opts,
-    page: '',
+    page,
     handler,
   })
 }
diff --git a/packages/next/src/build/webpack/loaders/next-middleware-loader.ts b/packages/next/src/build/webpack/loaders/next-middleware-loader.ts
@@ -3,8 +3,8 @@ import type {
   MiddlewareMatcher,
 } from '../../analysis/get-page-static-info'
 import { getModuleBuildInfo } from './get-module-build-info'
-import { stringifyRequest } from '../stringify-request'
 import { MIDDLEWARE_LOCATION_REGEXP } from '../../../lib/constants'
+import { loadEntrypoint } from '../../load-entrypoint'
 
 export type MiddlewareLoaderOptions = {
   absolutePagePath: string
@@ -27,7 +27,7 @@ export function decodeMatchers(encodedMatchers: string) {
   ) as MiddlewareMatcher[]
 }
 
-export default function middlewareLoader(this: any) {
+export default async function middlewareLoader(this: any) {
   const {
     absolutePagePath,
     page,
@@ -37,7 +37,11 @@ export default function middlewareLoader(this: any) {
     middlewareConfig: middlewareConfigBase64,
   }: MiddlewareLoaderOptions = this.getOptions()
   const matchers = encodedMatchers ? decodeMatchers(encodedMatchers) : undefined
-  const stringifiedPagePath = stringifyRequest(this, absolutePagePath)
+  const pagePath = this.utils.contextify(
+    this.context || this.rootContext,
+    absolutePagePath
+  )
+
   const middlewareConfig: MiddlewareConfig = JSON.parse(
     Buffer.from(middlewareConfigBase64, 'base64').toString()
   )
@@ -55,24 +59,8 @@ export default function middlewareLoader(this: any) {
     middlewareConfig,
   }
 
-  return `
-        import 'next/dist/esm/server/web/globals'
-        import { adapter } from 'next/dist/esm/server/web/adapter'
-        import * as _mod from ${stringifiedPagePath}
-
-        const mod = { ..._mod }
-        const handler = mod.middleware || mod.default
-
-        if (typeof handler !== 'function') {
-          throw new Error('The Middleware "pages${page}" must export a \`middleware\` or a \`default\` function');
-        }
-
-        export default function nHandler(opts) {
-          return adapter({
-            ...opts,
-            page: ${JSON.stringify(page)},
-            handler,
-          })
-        }
-    `
+  return await loadEntrypoint('middleware', {
+    VAR_USERLAND: pagePath,
+    VAR_DEFINITION_PAGE: page,
+  })
 }