From 8d10e2c31b4d94948b9f7f43e047a9964055c58c Mon Sep 17 00:00:00 2001
From: MURAKAMI Masahiko <fossamagna2@gmail.com>
Date: Fri, 2 Dec 2022 15:34:53 +0900
Subject: [PATCH] test_runner: add resetCalls to MockFunctionContext

This commit allows tests in test runner to reset the calls of mock function

Refs: https://github.com/nodejs/node/pull/45326#discussion_r1014728750
---
 doc/api/test.md                      |  8 ++++++++
 lib/internal/test_runner/mock.js     |  4 ++++
 test/parallel/test-runner-mocking.js | 17 +++++++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/doc/api/test.md b/doc/api/test.md
index 3588c6d6acd45b..3344ea9b53332c 100644
--- a/doc/api/test.md
+++ b/doc/api/test.md
@@ -870,6 +870,14 @@ test('changes a mock behavior once', (t) => {
 });
 ```
 
+### `ctx.resetCalls()`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Reset the calls of mock function.
+
 ### `ctx.restore()`
 
 <!-- YAML
diff --git a/lib/internal/test_runner/mock.js b/lib/internal/test_runner/mock.js
index 41bc3b7520431e..6b0ebad8d9dd2d 100644
--- a/lib/internal/test_runner/mock.js
+++ b/lib/internal/test_runner/mock.js
@@ -77,6 +77,10 @@ class MockFunctionContext {
     }
   }
 
+  resetCalls() {
+    this.#calls = [];
+  }
+
   trackCall(call) {
     ArrayPrototypePush(this.#calls, call);
   }
diff --git a/test/parallel/test-runner-mocking.js b/test/parallel/test-runner-mocking.js
index 82f25aeb3eab71..ef781f3088c1c4 100644
--- a/test/parallel/test-runner-mocking.js
+++ b/test/parallel/test-runner-mocking.js
@@ -780,6 +780,23 @@ test('local mocks are auto restored after the test finishes', async (t) => {
   assert.strictEqual(originalBar, obj.bar);
 });
 
+test('reset mock calls', (t) => {
+  const sum = (arg1, arg2) => arg1 + arg2;
+  const difference = (arg1, arg2) => arg1 - arg2;
+  const fn = t.mock.fn(sum, difference);
+
+  assert.strictEqual(fn(1, 2), -1);
+  assert.strictEqual(fn(2, 1), 1);
+  assert.strictEqual(fn.mock.calls.length, 2);
+  assert.strictEqual(fn.mock.callCount(), 2);
+
+  fn.mock.resetCalls();
+  assert.strictEqual(fn.mock.calls.length, 0);
+  assert.strictEqual(fn.mock.callCount(), 0);
+
+  assert.strictEqual(fn(3, 2), 1);
+});
+
 test('uses top level mock', () => {
   function sum(a, b) {
     return a + b;