feat: add spy option to vi.mockObject (#8285)

rChaoz · web-flow · commit 81d7601e453b · 2025-07-14T11:02:56.000+02:00
diff --git a/docs/api/vi.md b/docs/api/vi.md
@@ -417,6 +417,15 @@ expect(mocked.simple()).toBe('mocked')
 expect(mocked.nested.method()).toBe('mocked nested')
 ```
 
+Just like `vi.mock()`, you can pass `{ spy: true }` as a second argument to keep function implementations:
+
+```ts
+const spied = vi.mockObject(original, { spy: true })
+expect(spied.simple()).toBe('value')
+expect(spied.simple).toHaveBeenCalled()
+expect(spied.simple.mock.results[0]).toEqual({ type: 'return', value: 'value' })
+```
+
 ### vi.isMockFunction
 
 - **Type:** `(fn: Function) => boolean`
diff --git a/packages/vitest/src/integrations/vi.ts b/packages/vitest/src/integrations/vi.ts
@@ -292,12 +292,17 @@ export interface VitestUtils {
    *
    * expect(mocked.simple()).toBe('mocked')
    * expect(mocked.nested.method()).toBe('mocked nested')
+   *
+   * const spied = vi.mockObject(original, { spy: true })
+   * expect(spied.simple()).toBe('value')
+   * expect(spied.simple).toHaveBeenCalled()
+   * expect(spied.simple.mock.results[0]).toEqual({ type: 'return', value: 'value' })
    * ```
    *
    * @param value - The object to be mocked
    * @returns A deeply mocked version of the input object
    */
-  mockObject: <T>(value: T) => MaybeMockedDeep<T>
+  mockObject: <T>(value: T, options?: MockOptions) => MaybeMockedDeep<T>
 
   /**
    * Type helper for TypeScript. Just returns the object that was passed.
@@ -637,8 +642,8 @@ function createVitest(): VitestUtils {
       return _mocker().importMock(path, getImporter('importMock'))
     },
 
-    mockObject<T>(value: T) {
-      return _mocker().mockObject({ value }).value
+    mockObject<T>(value: T, options?: MockOptions) {
+      return _mocker().mockObject({ value }, undefined, options?.spy ? 'autospy' : 'automock').value
     },
 
     // this is typed in the interface so it's not necessary to type it here
diff --git a/test/core/test/vi.spec.ts b/test/core/test/vi.spec.ts
@@ -219,6 +219,13 @@ describe('testing vi utils', () => {
     expect(mocked.simple()).toBe('mocked')
     expect(mocked.nested.method()).toBe('mocked nested')
 
+    const spied = vi.mockObject(original, { spy: true })
+    expect(spied.simple()).toBe('value')
+    expect(spied.simple).toHaveBeenCalled()
+    expect(spied.simple.mock.results).toEqual([{ type: 'return', value: 'value' }])
+    spied.simple.mockReturnValue('still mocked')
+    expect(spied.simple()).toBe('still mocked')
+
     class OriginalClass {
       constructor() {
         throw new Error('should be mocked!')
