fix: adjust import analysis behavior to match Node (#16738)

packages/vite/src/node/ssr/ssrModuleLoader.ts

@@ -16,7 +16,6 @@ import {
 import {
  type SSRImportBaseMetadata,
  analyzeImportedModDifference,
- proxyGuardOnlyEsm,
 } from '../../shared/ssrTransform'
 import { SOURCEMAPPING_URL } from '../../shared/constants'
 import {
@@ -317,7 +316,7 @@ async function nodeImport(
  : undefined,
  metadata,
  )
- return proxyGuardOnlyEsm(mod, id)
+ return mod
  } else {
  return mod
  }

packages/vite/src/runtime/runtime.ts

@@ -8,10 +8,7 @@ import {
  unwrapId,
  wrapId,
 } from '../shared/utils'
-import {
- analyzeImportedModDifference,
- proxyGuardOnlyEsm,
-} from '../shared/ssrTransform'
+import { analyzeImportedModDifference } from '../shared/ssrTransform'
 import { ModuleCacheMap } from './moduleCache'
 import type {
  FetchResult,
@@ -193,7 +190,7 @@ export class ViteRuntime {
  const { id, type } = fetchResult
  if (type !== 'module' && type !== 'commonjs') return exports
  analyzeImportedModDifference(exports, id, type, metadata)
- return proxyGuardOnlyEsm(exports, id, metadata)
+ return exports
  }
 
  private async cachedRequest(

packages/vite/src/shared/ssrTransform.ts

@@ -28,48 +28,32 @@ export function analyzeImportedModDifference(
 ): void {
  // No normalization needed if the user already dynamic imports this module
  if (metadata?.isDynamicImport) return
- // If file path is ESM, everything should be fine
- if (moduleType === 'module') return
 
- // For non-ESM, named imports is done via static analysis with cjs-module-lexer in Node.js.
  // If the user named imports a specifier that can't be analyzed, error.
+ // If the module doesn't import anything explicitly, e.g. `import 'foo'` or
+ // `import * as foo from 'foo'`, we can skip.
  if (metadata?.importedNames?.length) {
  const missingBindings = metadata.importedNames.filter((s) => !(s in mod))
  if (missingBindings.length) {
  const lastBinding = missingBindings[missingBindings.length - 1]
- // Copied from Node.js
- throw new SyntaxError(`\
+
+ // For invalid named exports only, similar to how Node.js errors for top-level imports.
+ // But since we transform as dynamic imports, we need to emulate the error manually.
+ if (moduleType === 'module') {
+ throw new SyntaxError(
+ `[vite] The requested module '${rawId}' does not provide an export named '${lastBinding}'`,
+ )
+ } else {
+ // For non-ESM, named imports is done via static analysis with cjs-module-lexer in Node.js.
+ // Copied from Node.js
+ throw new SyntaxError(`\
 [vite] Named export '${lastBinding}' not found. The requested module '${rawId}' is a CommonJS module, which may not support all module.exports as named exports.
 CommonJS modules can always be imported via the default export, for example using:
 
 import pkg from '${rawId}';
 const {${missingBindings.join(', ')}} = pkg;
 `)
+ }
  }
  }
 }
-
-/**
- * Guard invalid named exports only, similar to how Node.js errors for top-level imports.
- * But since we transform as dynamic imports, we need to emulate the error manually.
- */
-export function proxyGuardOnlyEsm(
- mod: any,
- rawId: string,
- metadata?: SSRImportBaseMetadata,
-): any {
- // If the module doesn't import anything explicitly, e.g. `import 'foo'` or
- // `import * as foo from 'foo'`, we can skip the proxy guard.
- if (!metadata?.importedNames?.length) return mod
-
- return new Proxy(mod, {
- get(mod, prop) {
- if (prop !== 'then' && !(prop in mod)) {
- throw new SyntaxError(
- `[vite] The requested module '${rawId}' does not provide an export named '${prop.toString()}'`,
- )
- }
- return mod[prop]
- },
- })
-}