From 8b4873ca5b36e6733845f84a486be26596e6e2af Mon Sep 17 00:00:00 2001
From: Andrew Datsenko <asd@meta.com>
Date: Tue, 4 Feb 2025 10:06:15 -0800
Subject: [PATCH] Add `.toStrictEqual` (#49176)

Summary:

Changelog: [Internal]
Add missing jest expect apis

Reviewed By: rubennorte

Differential Revision: D69123117
---
 .../react-native-fantom/runtime/expect.js     | 25 +++++++++++++++
 .../src/__tests__/expect-itest.js             | 32 +++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/packages/react-native-fantom/runtime/expect.js b/packages/react-native-fantom/runtime/expect.js
index 05d99538dc1c6f..3be588d68d1c68 100644
--- a/packages/react-native-fantom/runtime/expect.js
+++ b/packages/react-native-fantom/runtime/expect.js
@@ -89,6 +89,31 @@ class Expect {
     }
   }
 
+  toStrictEqual(expected: mixed): void {
+    let expectedType: mixed =
+      typeof expected === 'object' && expected !== null
+        ? Object.getPrototypeOf(expected)
+        : null;
+    let receivedType: mixed =
+      typeof this.#received === 'object' && this.#received !== null
+        ? Object.getPrototypeOf(this.#received)
+        : null;
+    const pass =
+      deepEqual(this.#received, expected, {strict: true}) &&
+      expectedType === receivedType;
+    if (!this.#isExpectedResult(pass)) {
+      throw new ErrorWithCustomBlame(
+        `Expected${this.#maybeNotLabel()} to strictly equal:\n${
+          diff(expected, this.#received, {
+            contextLines: 1,
+            expand: false,
+            omitAnnotationLines: true,
+          }) ?? 'Failed to compare outputs'
+        }`,
+      ).blameToPreviousFrame();
+    }
+  }
+
   toBe(expected: mixed): void {
     const pass = this.#received === expected;
     if (!this.#isExpectedResult(pass)) {
diff --git a/packages/react-native-fantom/src/__tests__/expect-itest.js b/packages/react-native-fantom/src/__tests__/expect-itest.js
index a7edafea6996ed..a0eb8611690e99 100644
--- a/packages/react-native-fantom/src/__tests__/expect-itest.js
+++ b/packages/react-native-fantom/src/__tests__/expect-itest.js
@@ -111,6 +111,38 @@ describe('expect', () => {
     }).toThrow();
   });
 
+  test('toStrictEqual', () => {
+    class LaCroix {
+      flavor: string;
+      constructor(flavor: string) {
+        this.flavor = flavor;
+      }
+    }
+
+    expect({a: undefined, b: 2}).not.toStrictEqual({b: 2});
+    expect([2, undefined]).not.toStrictEqual([2]);
+    expect([2]).not.toStrictEqual([2, undefined]);
+    // This is part of spec https://jestjs.io/docs/expect#tostrictequalvalue
+    // eslint-disable-next-line no-sparse-arrays
+    expect([, 2]).not.toStrictEqual([undefined, 2]);
+    expect(new LaCroix('lemon')).not.toStrictEqual({flavor: 'lemon'});
+
+    expect({a: 1}).toStrictEqual({a: 1});
+    expect([2, undefined]).toStrictEqual([2, undefined]);
+    // This is part of spec https://jestjs.io/docs/expect#tostrictequalvalue
+    // eslint-disable-next-line no-sparse-arrays
+    expect([, 1]).toStrictEqual([, 1]);
+    expect(new LaCroix('lemon')).toStrictEqual(new LaCroix('lemon'));
+
+    expect(() => {
+      expect(new LaCroix('lemon')).toStrictEqual({flavor: 'lemon'});
+    }).toThrow();
+
+    expect(() => {
+      expect(new LaCroix('lemon')).not.toStrictEqual(new LaCroix('lemon'));
+    }).toThrow();
+  });
+
   test('toBeInstanceOf', () => {
     class Class {}