fix(spy): do not mock overriden method, if parent was automocked (#9116)

sheremet-va · web-flow · commit 1a24607b4bd1 · 2025-11-27T16:17:42.000+01:00
diff --git a/packages/spy/src/index.ts b/packages/spy/src/index.ts
@@ -433,6 +433,12 @@ function createMock(
           // are only used by the automocker, so this doesn't matter
           for (const prop of prototypeMembers) {
             const prototypeMock = returnValue[prop]
+            // the method was overidden because of inheritence, ignore it
+            // eslint-disable-next-line ts/no-use-before-define
+            if (prototypeMock !== mock.prototype[prop]) {
+              continue
+            }
+
             const isMock = isMockFunction(prototypeMock)
             const prototypeState = isMock ? prototypeMock.mock : undefined
             const prototypeConfig = isMock ? MOCK_CONFIGS.get(prototypeMock) : undefined
diff --git a/test/core/src/class-inheritence/bar.ts b/test/core/src/class-inheritence/bar.ts
@@ -0,0 +1,11 @@
+import { Foo } from './foo.js'
+
+export class Bar extends Foo {
+  override doSomething(): boolean {
+    return true
+  }
+
+  doSomethingElse(): boolean {
+    return true
+  }
+}
diff --git a/test/core/src/class-inheritence/foo.ts b/test/core/src/class-inheritence/foo.ts
@@ -0,0 +1,9 @@
+export class Foo {
+  doSomething(): boolean {
+    return false
+  }
+
+  unused() {
+    //
+  }
+}
diff --git a/test/core/test/mocking/automocking-class-inheritence.test.ts b/test/core/test/mocking/automocking-class-inheritence.test.ts
@@ -0,0 +1,57 @@
+// bar.spec.ts
+import { describe, expect, it, vi } from 'vitest'
+import { Bar } from '../../src/class-inheritence/bar'
+
+vi.mock(import('./../../src/class-inheritence/foo'))
+
+describe('not mocking class when parent is mocked', () => {
+  describe('doSomething', () => {
+    it('returns true', () => {
+      const bar = new Bar()
+      expect(bar.doSomething()).toBe(true)
+    })
+
+    it('should match the prototype', () => {
+      const bar = new Bar()
+      expect(bar.doSomething).toBe(Bar.prototype.doSomething)
+    })
+
+    it('should not be mocked', () => {
+      const bar = new Bar()
+      expect(bar.doSomething).not.toHaveProperty('mock')
+    })
+  })
+
+  describe('doSomethingElse', () => {
+    it('returns true', () => {
+      const bar = new Bar()
+      expect(bar.doSomethingElse()).toBe(true)
+    })
+
+    it('should match the prototype', () => {
+      const bar = new Bar()
+      expect(bar.doSomethingElse).toBe(Bar.prototype.doSomethingElse)
+    })
+
+    it('should not be mocked', () => {
+      const bar = new Bar()
+      expect(bar.doSomethingElse).not.toHaveProperty('mock')
+    })
+  })
+})
+
+describe('mocking class when parent is not mocked', () => {
+  it('mocks correctly', () => {
+    class Bar {
+      doSomething() {}
+    }
+
+    const Zoo = vi.mockObject(class Zoo extends Bar {
+      ownMethod() {}
+    })
+
+    const zoo = new Zoo()
+    expect(vi.isMockFunction(zoo.doSomething)).toBe(true)
+    expect(vi.isMockFunction(zoo.ownMethod)).toBe(true)
+  })
+})
