solution

src/ifElse.test.js

@@ -1,11 +1,33 @@
 'use strict';
 
 describe('ifElse', () => {
-  // const { ifElse } = require('./ifElse');
+  const { ifElse } = require('./ifElse');
 
-  it('should ', () => {
+  let condition;
+  let first;
+  let second;
 
+  beforeEach(() => {
+    condition = jest.fn();
+    first = jest.fn();
+    second = jest.fn();
   });
 
-  // write tests here
+  it('should be function', () => {
+    expect(typeof ifElse).toBe('function');
+  });
+
+  it(`should call 'first' if 'condition' returns true`, () => {
+    condition.mockReturnValue(true);
+    ifElse(condition, first, second);
+    expect(first).toHaveBeenCalled();
+    expect(second).not.toHaveBeenCalled();
+  });
+
+  it(`should call 'second' if 'condition' returns false`, () => {
+    condition.mockReturnValue(false);
+    ifElse(condition, first, second);
+    expect(first).not.toHaveBeenCalled();
+    expect(second).toHaveBeenCalled();
+  });
 });