Update toStrictEqual() to be able to check jest.fn().mock.calls etc. (#…

…13960)

CHANGELOG.md

@@ -23,6 +23,7 @@
 - `[jest-circus]` Update message printed on test timeout ([#13830](https://github.com/facebook/jest/pull/13830))
 - `[jest-circus]` Avoid creating the word "testfalse" when `takesDoneCallback` is `false` in the message printed on test timeout AND updated timeouts test ([#13954](https://github.com/facebook/jest/pull/13954))
 - `[jest-environment-jsdom]` Stop setting `document` to `null` on teardown ([#13972](https://github.com/facebook/jest/pull/13972))
+- `[@jest/expect-utils]` Update `toStrictEqual()` to be able to check `jest.fn().mock.calls` ([#13960](https://github.com/facebook/jest/pull/13960))
 - `[@jest/test-result]` Allow `TestResultsProcessor` type to return a Promise ([#13950](https://github.com/facebook/jest/pull/13950))
 
 ### Chore & Maintenance

packages/expect-utils/src/__tests__/utils.test.ts

@@ -15,6 +15,7 @@ import {
   getPath,
   iterableEquality,
   subsetEquality,
+  typeEquality,
 } from '../utils';
 
 describe('getPath()', () => {
@@ -546,6 +547,12 @@ describe('iterableEquality', () => {
   });
 });
 
+describe('typeEquality', () => {
+  test('returns undefined if given mock.calls and []', () => {
+    expect(typeEquality(jest.fn().mock.calls, [])).toBeUndefined();
+  });
+});
+
 describe('arrayBufferEquality', () => {
   test('returns undefined if given a non instance of ArrayBuffer', () => {
     expect(arrayBufferEquality(2, 's')).toBeUndefined();

packages/expect-utils/src/utils.ts

@@ -370,7 +370,16 @@ export const subsetEquality = (
 
 // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
 export const typeEquality = (a: any, b: any): boolean | undefined => {
-  if (a == null || b == null || a.constructor === b.constructor) {
+  if (
+    a == null ||
+    b == null ||
+    a.constructor === b.constructor ||
+    // Since Jest globals are different from Node globals,
+    // constructors are different even between arrays when comparing properties of mock objects.
+    // Both of them should be able to compare correctly when they are array-to-array.
+    // https://github.com/facebook/jest/issues/2549
+    (Array.isArray(a) && Array.isArray(b))
+  ) {
     return undefined;
   }