fix(vite-node): don't fallback to cjs by default (#924)

docs/config/index.md

@@ -68,6 +68,22 @@ Externalize means that Vite will bypass the package to native Node. Externalized
 
 Vite will process inlined modules. This could be helpful to handle packages that ship `.js` in ESM format (that Node can't handle).
 
+#### deps.fallbackCJS
+
+- **Type** `boolean`
+- **Default:** `false`
+
+When a dependency is a valid ESM package, try to guess the cjs version based on the path.
+
+This might potentially cause some misalignment if a package has different logic in ESM and CJS mode.
+
+#### deps.interopDefault
+
+- **Type:** `boolean`
+- **Default:** `true`
+
+Interpret CJS module's default as named exports.
+
 ### globals
 
 - **Type:** `boolean`
@@ -223,10 +239,6 @@ Maximum number of threads
 
 Minimum number of threads
 
-### interopDefault
-
-- **Type:** `boolean`
-
 ### testTimeout
 
 - **Type:** `number`

packages/vite-node/src/externalize.ts

@@ -72,7 +72,8 @@ async function _shouldExternalize(
     return id
 
   const isNodeModule = id.includes('/node_modules/')
-  id = isNodeModule ? guessCJSversion(id) || id : id
+  const guessCJS = isNodeModule && options?.fallbackCJS
+  id = guessCJS ? guessCJSversion(id) || id : id
 
   if (matchExternalizePattern(id, defaultInline))
     return false

packages/vite-node/src/types.ts

@@ -3,7 +3,7 @@ export interface DepsHandlingOptions {
   inline?: (string | RegExp)[]
   /**
    * Try to guess the CJS version of a package when it's invalid ESM
-   * @default true
+   * @default false
    */
   fallbackCJS?: boolean
 }

packages/vitest/src/types/config.ts

@@ -73,7 +73,7 @@ export interface InlineConfig {
      * This will significantly improve the performance in huge repo, but might potentially
      * cause some misalignment if a package have different logic in ESM and CJS mode.
      *
-     * @default true
+     * @default false
      */
     fallbackCJS?: boolean
   }