Mocking and faking in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Laravel test using a fake?

Consider this Laravel test code that fakes the mail sending. What will be the result of the assertion?

Laravel

<?php
use Illuminate\Support\Facades\Mail;
use Tests\TestCase;

class UserTest extends TestCase
{
    public function test_mail_is_sent()
    {
        Mail::fake();

        Mail::to('[e-mail]')->send(new \App\Mail\WelcomeMail());

        Mail::assertSent(\App\Mail\WelcomeMail::class);
    }
}

A The test fails because Mail::fake() disables sending mails and no mail is sent.

B The test passes because the mail was sent and caught by the fake.

C The test throws an error because Mail::assertSent() cannot be used after Mail::fake().

D The test passes but Mail::assertSent() always returns true regardless of mails sent.

💡 Hint

Think about what Mail::fake() does and how assertSent works with it.

Mail::fake() prevents actual emails from being sent but records the mailables sent. The assertion checks if the mail was sent, so the test passes.

❓ state_output

intermediate

What is the value of the mocked method call count?

Given this Laravel test using a mock, what is the value of $count after the calls?

Laravel

<?php
use Illuminate\Support\Facades\Cache;
use Tests\TestCase;

class CacheTest extends TestCase
{
    public function test_cache_mock()
    {
        $mock = \Mockery::mock('alias:Illuminate\Support\Facades\Cache');
        $mock->shouldReceive('put')->twice()->andReturn(true);

        Cache::put('key1', 'value1', 10);
        Cache::put('key2', 'value2', 10);

        $count = $mock->mockery_getExpectationCount();

        return $count;
    }
}

A 0

B 1

C Throws an error because mockery_getExpectationCount() is not a method

D 2

💡 Hint

Check if mockery_getExpectationCount() is a valid method on the mock object.

The method mockery_getExpectationCount() does not exist on the mock object, so calling it causes a fatal error.

🔧 Debug

advanced

Why does this Laravel test fail when mocking a repository?

This test tries to mock a repository method but fails with a method not found error. Why?

Laravel

<?php
use Tests\TestCase;
use App\Repositories\UserRepository;
use Mockery;

class UserRepositoryTest extends TestCase
{
    public function test_find_user()
    {
        $mock = Mockery::mock(UserRepository::class);
        $mock->shouldReceive('find')->with(1)->andReturn('User1');

        $result = $mock->find(1);

        $this->assertEquals('User1', $result);
    }
}

A The test passes without errors and returns 'User1' as expected.

B The test fails because the find method does not exist on UserRepository, so Mockery cannot mock it.

C The test fails because Mockery requires calling Mockery::close() after the test to avoid errors.

D The test fails because UserRepository is a concrete class and Mockery cannot mock concrete classes by default.

💡 Hint

Check if the method being mocked exists and if Mockery supports mocking this class.

Mockery can mock concrete classes and the find method exists on UserRepository. The test passes and returns the mocked value.

📝 Syntax

advanced

Which option correctly fakes the event dispatch in Laravel?

You want to fake event dispatching in a Laravel test. Which code snippet is correct?

A

Event::fake();
Event::assertDispatched(UserRegistered::class);

B

Event::fake(UserRegistered::class);
Event::assertDispatched(UserRegistered::class);

C

Event::fake();
Event::assertDispatched('UserRegistered');

D

Event::fake();
Event::assertDispatched('App\Events\UserRegistered');

💡 Hint

Check the correct usage of Event::fake() and assertDispatched with class names.

Event::fake() fakes all events. assertDispatched expects the event class name, not a string or partial name.

🧠 Conceptual

expert

What is the main difference between mocking and faking in Laravel testing?

Choose the best explanation of how mocking and faking differ in Laravel testing.

A Mocking disables all functionality of a class, while faking allows the original methods to run but logs calls.

B Mocking is only used for database queries, while faking is used for HTTP requests and events.

C Mocking and faking are the same in Laravel; both replace real implementations with test doubles.

D Mocking replaces a class or method with a dummy that records calls and can return custom values, while faking replaces a whole service with a simplified version that simulates behavior without side effects.

💡 Hint

Think about the scope and purpose of mocks versus fakes in tests.

Mocking creates controlled stand-ins for specific methods or classes to verify interactions. Faking replaces entire services with simplified versions to avoid side effects like sending emails or dispatching events.