Database testing (RefreshDatabase) in Laravel - Mini Project: Build & Apply

Database testing with RefreshDatabase in Laravel

📖 Scenario: You are building a simple Laravel application that stores information about books. You want to write tests that check if the database correctly saves and retrieves book data. To keep your tests clean and isolated, you will use Laravel's RefreshDatabase trait to reset the database before each test.

🎯 Goal: Write a Laravel test class that uses the RefreshDatabase trait. Create a test that inserts a book record into the database and verifies it exists.

📋 What You'll Learn

Create a Laravel test class named BookTest

Use the RefreshDatabase trait in the test class

Write a test method named test_book_can_be_created

Insert a book with title 'The Great Gatsby' and author 'F. Scott Fitzgerald'

Assert the database has the inserted book record

💡 Why This Matters

🌍 Real World

Database testing is essential to ensure your application stores and retrieves data correctly. Using RefreshDatabase keeps tests isolated and reliable.

💼 Career

Many Laravel developer roles require writing automated tests to maintain code quality and prevent bugs in database operations.

1

Create the test class with namespace and imports

Create a Laravel test class named BookTest inside the Tests\Feature namespace. Import Tests\TestCase and Illuminate\Foundation\Testing\RefreshDatabase. Define the class extending TestCase.

Laravel

<?php

namespace Tests\Feature;

use Tests\TestCase;
use Illuminate\Foundation\Testing\RefreshDatabase;

class BookTest extends TestCase
{
    // Your code here
}

Need a hint?

Remember to declare the namespace and import the RefreshDatabase trait. Use the trait inside the class.

2

Add the test method skeleton

Inside the BookTest class, add a public method named test_book_can_be_created with no parameters. Leave the method body empty for now.

Laravel

<?php

namespace Tests\Feature;

use Tests\TestCase;
use Illuminate\Foundation\Testing\RefreshDatabase;

class BookTest extends TestCase
{
    use RefreshDatabase;

    public function test_book_can_be_created()
    {
        // Your code here
    }
}

Need a hint?

Define a public function with the exact name test_book_can_be_created inside the class.

3

Insert a book record into the database

Inside the test_book_can_be_created method, insert a new record into the books table with title set to 'The Great Gatsby' and author set to 'F. Scott Fitzgerald' using Laravel's DB::table('books')->insert() method. Import the DB facade at the top.

Laravel

<?php

namespace Tests\Feature;

use Tests\TestCase;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Illuminate\Support\Facades\DB;

class BookTest extends TestCase
{
    use RefreshDatabase;

    public function test_book_can_be_created()
    {
        // Insert book record here
    }
}

Need a hint?

Use DB::table('books')->insert() with an array containing the exact keys and values.

4

Assert the book record exists in the database

Still inside the test_book_can_be_created method, add an assertion using $this->assertDatabaseHas('books', [...]) to check that the books table contains a record with title 'The Great Gatsby' and author 'F. Scott Fitzgerald'.

Laravel

insert([
            'title' => 'The Great Gatsby',
            'author' => 'F. Scott Fitzgerald'
        ]);

        // Add assertion to check database here
    }
}

Need a hint?

Use $this->assertDatabaseHas() with the exact table name and data array.