From 6b3e36d4e9fd029984ce0f6a723ddb3fdce92379 Mon Sep 17 00:00:00 2001
From: Vladimir <sleuths.slews0s@icloud.com>
Date: Fri, 6 Jan 2023 13:11:10 +0100
Subject: [PATCH] fix: allow mocking CJS module with interoped default (#2598)

* fix: allow mocking CJS module with interoped default

* chore: cleanup

* chore: cleanup
---
 examples/mocks/src/external/default-function.cjs |  3 +++
 examples/mocks/test/external.test.ts             |  7 +++++++
 examples/mocks/vite.config.ts                    |  1 +
 packages/vite-node/src/client.ts                 | 15 +++++++++++----
 packages/vitest/src/runtime/execute.ts           |  4 +++-
 5 files changed, 25 insertions(+), 5 deletions(-)
 create mode 100644 examples/mocks/src/external/default-function.cjs

diff --git a/examples/mocks/src/external/default-function.cjs b/examples/mocks/src/external/default-function.cjs
new file mode 100644
index 000000000..6d33c32d8
--- /dev/null
+++ b/examples/mocks/src/external/default-function.cjs
@@ -0,0 +1,3 @@
+module.exports = function () {
+  return true
+}
diff --git a/examples/mocks/test/external.test.ts b/examples/mocks/test/external.test.ts
index fcdb8a631..fe53d7d0a 100644
--- a/examples/mocks/test/external.test.ts
+++ b/examples/mocks/test/external.test.ts
@@ -1,7 +1,14 @@
 import '../src/external/external.mjs'
 import { expect, test, vi } from 'vitest'
 import axios from 'axios'
+import defaultFunc from '../src/external/default-function.cjs'
+
+vi.mock('../src/external/default-function.cjs')
 
 test('axios is mocked', () => {
   expect(vi.isMockFunction(axios.get)).toBe(true)
 })
+
+test('defaultFunc is mocked', () => {
+  expect(vi.isMockFunction(defaultFunc)).toBe(true)
+})
diff --git a/examples/mocks/vite.config.ts b/examples/mocks/vite.config.ts
index 46dc4f567..34f684a68 100644
--- a/examples/mocks/vite.config.ts
+++ b/examples/mocks/vite.config.ts
@@ -25,6 +25,7 @@ export default defineConfig({
     environment: 'node',
     deps: {
       external: [/src\/external/],
+      interopDefault: true,
     },
   },
 })
diff --git a/packages/vite-node/src/client.ts b/packages/vite-node/src/client.ts
index 7d7fa70bf..6286f0a87 100644
--- a/packages/vite-node/src/client.ts
+++ b/packages/vite-node/src/client.ts
@@ -424,6 +424,14 @@ export class ViteNodeRunner {
 
     const { mod, defaultExport } = interopModule(importedModule)
 
+    const modKeys = Reflect.ownKeys(mod)
+    let defaultKeys = !isPrimitive(defaultExport) ? Reflect.ownKeys(defaultExport) : []
+    // remove reserved keys from default keys
+    if (typeof mod !== 'function' && typeof defaultExport === 'function') {
+      const reservedKeys = ['arguments', 'caller', 'prototype', 'name', 'length']
+      defaultKeys = defaultKeys.filter(n => typeof n === 'string' && !reservedKeys.includes(n))
+    }
+
     return new Proxy(mod, {
       get(mod, prop) {
         if (prop === 'default')
@@ -436,11 +444,10 @@ export class ViteNodeRunner {
         return prop in mod || (defaultExport && prop in defaultExport)
       },
       // this is needed for mocker to know what is available to mock
-      ownKeys(mod) {
-        const keys = Reflect.ownKeys(mod)
+      ownKeys() {
         if (!defaultExport || isPrimitive(defaultExport))
-          return keys
-        const allKeys = [...keys, 'default', ...Reflect.ownKeys(defaultExport)]
+          return modKeys
+        const allKeys = [...modKeys, 'default', ...defaultKeys]
         return Array.from(new Set(allKeys))
       },
       getOwnPropertyDescriptor(mod, prop) {
diff --git a/packages/vitest/src/runtime/execute.ts b/packages/vitest/src/runtime/execute.ts
index f08d2095f..e624057ee 100644
--- a/packages/vitest/src/runtime/execute.ts
+++ b/packages/vitest/src/runtime/execute.ts
@@ -73,6 +73,8 @@ export class VitestRunner extends ViteNodeRunner {
   }
 
   shouldInterop(path: string, mod: any) {
-    return this.options.interopDefault ?? (getCurrentEnvironment() !== 'node' && super.shouldInterop(path, mod))
+    if (this.options.interopDefault === false)
+      return false
+    return (this.options.interopDefault || getCurrentEnvironment() !== 'node') && super.shouldInterop(path, mod)
   }
 }
-- 
2.51.2