Add .toStrictEqual

Summary:
Changelog: [Internal]
Add missing jest expect apis

Differential Revision: D69123117

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)) {

packages/react-native-fantom/src/__tests__/expect-itest.js

@@ -111,6 +111,23 @@ 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'});
+  });
+
   test('toBeInstanceOf', () => {
     class Class {}