Add .toBeDefined and .toBeUndefined (facebook#49168)

Summary:

Changelog: [Internal]
Add missing jest expect apis

Differential Revision: D69119330

packages/react-native-fantom/runtime/expect.js

@@ -117,6 +117,24 @@ class Expect {
     }
   }
 
+  toBeDefined(): void {
+    const pass = this.#received !== undefined;
+    if (!this.#isExpectedResult(pass)) {
+      throw new ErrorWithCustomBlame(
+        `Expected ${String(this.#received)}${this.#maybeNotLabel()} to be defined`,
+      ).blameToPreviousFrame();
+    }
+  }
+
+  toBeUndefined(): void {
+    const pass = this.#received === undefined;
+    if (!this.#isExpectedResult(pass)) {
+      throw new ErrorWithCustomBlame(
+        `Expected ${String(this.#received)}${this.#maybeNotLabel()} to be undefined`,
+      ).blameToPreviousFrame();
+    }
+  }
+
   toBeNull(): void {
     const pass = this.#received == null;
     if (!this.#isExpectedResult(pass)) {

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

@@ -148,6 +148,36 @@ describe('expect', () => {
     }).toThrow();
   });
 
+  test('toBeDefined', () => {
+    expect(null).toBeDefined();
+    expect(false).toBeDefined();
+    expect('value').toBeDefined();
+    expect(undefined).not.toBeDefined();
+
+    expect(() => {
+      expect({}).not.toBeDefined();
+    }).toThrow();
+
+    expect(() => {
+      expect(undefined).toBeDefined();
+    }).toThrow();
+  });
+
+  test('toBeUndefined', () => {
+    expect(undefined).toBeUndefined();
+    expect(null).not.toBeUndefined();
+    expect(false).not.toBeUndefined();
+    expect('value').not.toBeUndefined();
+
+    expect(() => {
+      expect(undefined).not.toBeUndefined();
+    }).toThrow();
+
+    expect(() => {
+      expect({}).toBeUndefined();
+    }).toThrow();
+  });
+
   ['toBeCalled', 'toHaveBeenCalled'].map(toHaveBeenCalledAlias =>
     test(toHaveBeenCalledAlias, () => {
       const fn = jest.fn();