PHPUnit setup in Laravel - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

Understanding PHPUnit Test Discovery in Laravel

Given a Laravel project with PHPUnit installed, which folder does Laravel automatically scan to find test classes when running php artisan test?

A The <code>database/tests</code> directory

B The <code>tests</code> directory

C The <code>resources/tests</code> directory

D The <code>app/Tests</code> directory

💡 Hint

Think about where Laravel places test files by default.

Laravel places all test classes inside the tests directory at the project root. This is where PHPUnit looks for tests when running php artisan test.

📝 Syntax

intermediate

Correct PHPUnit Test Method Signature in Laravel

Which of the following is the correct way to define a test method inside a Laravel PHPUnit test class?

A public function testUserCreation() {}

B function testUserCreation() {}

C public testUserCreation() {}

D private function testUserCreation() {}

💡 Hint

Test methods must be accessible to PHPUnit and follow naming conventions.

Test methods must be public and start with test or have the @test annotation. Option A follows this rule.

❓ state_output

advanced

Output of Running a Failing Test in Laravel

What output will you see in the terminal if a Laravel PHPUnit test method contains $this->assertTrue(false);?

Laravel

<?php

use Tests\TestCase;

class ExampleTest extends TestCase
{
    public function testFailure()
    {
        $this->assertTrue(false);
    }
}

A A syntax error because <code>assertTrue</code> is not defined

B A success message showing all tests passed

C No output because the test is skipped by default

D A failure message showing the test <code>testFailure</code> failed with an assertion error

💡 Hint

Think about what happens when an assertion fails in PHPUnit.

When $this->assertTrue(false); runs, the assertion fails. PHPUnit reports this as a failed test with details.

🔧 Debug

advanced

Identifying the Cause of a PHPUnit Configuration Error in Laravel

You run php artisan test but get the error: Could not find a matching version of package phpunit/phpunit. What is the most likely cause?

A PHPUnit is not installed or missing from <code>composer.json</code> dependencies

B The <code>tests</code> directory is missing

C The <code>phpunit.xml</code> file is corrupted

D The Laravel version is too old to support PHPUnit

💡 Hint

Check your project's dependencies and composer setup.

This error usually means PHPUnit is not installed or not listed in the composer.json file. Running composer require --dev phpunit/phpunit fixes it.

🧠 Conceptual

expert

Understanding Laravel's Test Database Refresh Behavior

When using the RefreshDatabase trait in a Laravel PHPUnit test, what happens before each test method runs?

A The database connection is closed but data remains unchanged

B Only the tables used in the test are truncated

C The database is migrated fresh, rolling back and re-running all migrations

D The database is backed up but not modified

💡 Hint

Think about how Laravel ensures a clean database state for tests.

The RefreshDatabase trait runs all migrations fresh before each test, ensuring a clean database state.

Practice

1. What is the primary purpose of using PHPUnit in a Laravel project?

easy

A. To test the application and catch bugs early

B. To deploy the application to a server

C. To write database migration scripts

D. To create user interface designs

Solution

1. Step 1: Understand PHPUnit's role

   PHPUnit is a testing framework used to check if code works correctly.

2. Step 2: Connect PHPUnit to Laravel usage

   In Laravel, PHPUnit helps find bugs early by running automated tests.

3. Final Answer:

   To test the application and catch bugs early -> Option A

4. Quick Check:

   Testing = Catch bugs early [OK]

Hint: PHPUnit is for testing, not deployment or design [OK]

Common Mistakes:

• Confusing testing with deployment
• Thinking PHPUnit creates UI or migrations
• Assuming PHPUnit runs the app

2. Which command correctly creates a new test class in Laravel using Artisan?

easy

A. php artisan make:test UserTest

B. php artisan create:test UserTest

C. php artisan test:make UserTest

D. php artisan generate:test UserTest

Solution

1. Step 1: Recall Laravel Artisan test creation command

   The correct command to create a test is php artisan make:test.

2. Step 2: Match the command with options

   Only php artisan make:test UserTest uses the correct syntax: php artisan make:test UserTest.

3. Final Answer:

   php artisan make:test UserTest -> Option A

4. Quick Check:

   Make test command = make:test [OK]

Hint: Use 'make:test' to create tests with Artisan [OK]

Common Mistakes:

• Using incorrect Artisan command verbs
• Mixing test creation with test running commands
• Misspelling 'make:test'

3. Given this test method in Laravel, what will be the output when running php artisan test if the home page returns status 200?

public function test_home_page_status()
{
    $response = $this->get('/');
    $response->assertStatus(200);
}

medium

A. Test fails with status code error

B. Test passes with success message

C. Syntax error in test method

D. Test is skipped automatically

Solution

1. Step 1: Analyze the test method

   The test sends a GET request to '/' and expects HTTP status 200.

2. Step 2: Check expected vs actual response

   If the home page returns 200, the assertion assertStatus(200) passes.

3. Final Answer:

   Test passes with success message -> Option B

4. Quick Check:

   Correct status = test passes [OK]

Hint: If status matches assertStatus, test passes [OK]

Common Mistakes:

• Assuming test fails if status is 200
• Confusing assertStatus with assertSee
• Thinking test skips without reason

4. You wrote this test but it fails with an error:

public function test_example()
{
    $response = $this->get('/home');
    $response->assertStatus(200)
}

What is the likely cause?

medium

A. Test method name is invalid

B. Wrong HTTP method used in get()

C. Missing semicolon after assertStatus(200)

D. Route '/home' does not exist

Solution

1. Step 1: Check syntax in test method

   The line $response->assertStatus(200) lacks a semicolon at the end.

2. Step 2: Understand PHP syntax rules

   Missing semicolon causes a syntax error and test fails to run.

3. Final Answer:

   Missing semicolon after assertStatus(200) -> Option C

4. Quick Check:

   Semicolon missing = syntax error [OK]

Hint: Always end PHP statements with semicolon [OK]

Common Mistakes:

• Ignoring missing semicolon errors
• Assuming wrong HTTP method causes syntax error
• Thinking test method name causes syntax error

5. You want to run only tests related to user authentication in Laravel. Which command helps you run tests in the tests/Feature/AuthTest.php file only?

hard

A. php artisan test --run=AuthTest

B. php artisan make:test AuthTest

C. php artisan test --only=AuthTest

D. php artisan test --filter=AuthTest

Solution

1. Step 1: Identify how to filter tests in Laravel

   Laravel's test command supports --filter to run specific tests.

2. Step 2: Match correct syntax for filtering

   php artisan test --filter=AuthTest uses php artisan test --filter=AuthTest, which runs tests matching 'AuthTest'.

3. Final Answer:

   php artisan test --filter=AuthTest -> Option D

4. Quick Check:

   Filter option runs specific tests [OK]

Hint: Use --filter to run specific test files or methods [OK]

Common Mistakes:

• Using nonexistent options like --only or --run
• Confusing make:test with running tests
• Not specifying filter correctly