test_runner: fix mock.property() restore for accessors

lib/internal/test_runner/mock/mock.js

@@ -359,7 +359,6 @@ class MockPropertyContext {
   #object;
   #propertyName;
   #value;
-  #originalValue;
   #descriptor;
   #accesses;
   #onceValues;
@@ -369,8 +368,7 @@ class MockPropertyContext {
     this.#accesses = [];
     this.#object = object;
     this.#propertyName = propertyName;
-    this.#originalValue = object[propertyName];
-    this.#value = arguments.length > 2 ? value : this.#originalValue;
+    this.#value = arguments.length > 2 ? value : object[propertyName];
     this.#descriptor = ObjectGetOwnPropertyDescriptor(object, propertyName);
     if (!this.#descriptor) {
       throw new ERR_INVALID_ARG_VALUE(
@@ -476,7 +474,6 @@ class MockPropertyContext {
     ObjectDefineProperty(this.#object, this.#propertyName, {
       __proto__: null,
       ...this.#descriptor,
-      value: this.#originalValue,
     });
   }
 }

test/parallel/test-runner-mocking.js

@@ -1275,6 +1275,34 @@ test('throws if setting a non-writable property', (t) => {
   assert.throws(() => { obj.bar = 3; }, { code: 'ERR_INVALID_ARG_VALUE' });
 });
 
+test('restores an accessor property', (t) => {
+  const obj = {
+    get foo() { return 'real'; },
+  };
+  const original = Object.getOwnPropertyDescriptor(obj, 'foo');
+
+  const prop = t.mock.property(obj, 'foo', 'mocked');
+  assert.strictEqual(obj.foo, 'mocked');
+
+  prop.mock.restore();
+  assert.deepStrictEqual(Object.getOwnPropertyDescriptor(obj, 'foo'), original);
+});
+
+test('accessor property mocks are auto restored after the test finishes', async (t) => {
+  const obj = {
+    get foo() { return 'real'; },
+  };
+  const original = Object.getOwnPropertyDescriptor(obj, 'foo');
+
+  await t.test('creates an accessor property mock that is auto restored', (t) => {
+    t.mock.property(obj, 'foo', 'mocked');
+    assert.strictEqual(obj.foo, 'mocked');
+  });
+
+  assert.deepStrictEqual(Object.getOwnPropertyDescriptor(obj, 'foo'), original);
+  assert.strictEqual(obj.foo, 'real');
+});
+
 test('throws if property does not exist', (t) => {
   assert.throws(() => {
     t.mock.property({}, 'doesNotExist', 1);