fix: default export module transformation for vitest spy (#8567)

Author: konpeki622

packages/vite/src/node/ssr/__tests__/ssrTransform.spec.ts

@@ -306,7 +306,7 @@ test('should declare variable for imported super class', async () => {
     class A extends Foo {}
     class B extends Foo {}
     Object.defineProperty(__vite_ssr_exports__, \\"B\\", { enumerable: true, configurable: true, get(){ return B }});
-    Object.defineProperty(__vite_ssr_exports__, \\"default\\", { enumerable: true, value: A });"
+    Object.defineProperty(__vite_ssr_exports__, \\"default\\", { enumerable: true, configurable: true, value: A });"
   `)
 })
 
@@ -338,7 +338,7 @@ test('should handle default export variants', async () => {
   ).toMatchInlineSnapshot(`
     "function foo() {}
     foo.prototype = Object.prototype;
-    Object.defineProperty(__vite_ssr_exports__, \\"default\\", { enumerable: true, value: foo });"
+    Object.defineProperty(__vite_ssr_exports__, \\"default\\", { enumerable: true, configurable: true, value: foo });"
   `)
   // default named classes
   expect(
@@ -353,7 +353,7 @@ test('should handle default export variants', async () => {
     "class A {}
     class B extends A {}
     Object.defineProperty(__vite_ssr_exports__, \\"B\\", { enumerable: true, configurable: true, get(){ return B }});
-    Object.defineProperty(__vite_ssr_exports__, \\"default\\", { enumerable: true, value: A });"
+    Object.defineProperty(__vite_ssr_exports__, \\"default\\", { enumerable: true, configurable: true, value: A });"
   `)
 })
 

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

@@ -188,7 +188,7 @@ async function ssrTransformScript(
         s.remove(node.start, node.start + 15 /* 'export default '.length */)
         s.append(
           `\nObject.defineProperty(${ssrModuleExportsKey}, "default", ` +
-            `{ enumerable: true, value: ${name} });`
+            `{ enumerable: true, configurable: true, value: ${name} });`
         )
       } else {
         // anonymous default exports