Write better Laravel tests

1.php

<?php

public function test_users_can_get_their_categories_list()
{
    factory(Category::class, 5)->create();
    $user = factory(User::class)->create();
    Passport::actingAs($user);

    $response = $this->get('api/categories');
    
    $response->assertSuccessful();
    $response->assertJsonCount(5);
    $response->assertJsonStructure([
        [
            'id',
            'name',
            'type',
        ],
    ]);
    foreach ($response->json() as $category) {
        $this->assertEquals($user->id,$category['user_id']);
    }
}

2.php

<?php

public function test_users_can_get_their_categories_list()
{
    // ...

    $response = $this->get('api/categories')
            ->assertSuccessful()
            ->dump()
            ->assertJsonCount(5)
            ->assertJsonStructure([
                [
                    'id',
                    'name',
                    'type',
                ],
            ]);

    foreach ($response->json() as $category) {
        $this->assertEquals($user->id,$category['user_id']);
    }
}

3.php

<?php

// add this macro to your service provider
TestResponse::macro('assertJsonPaths', function ($path, $expected) {
    foreach ($this->json($path) as $real) {
        PHPUnit::assertEquals($expected, $real);
    }

    return $this;
});

// then refactor the test 
public function test_users_can_get_their_categories_list()
{
    factory(Category::class, 5)->create();
    $user = factory(User::class)->create();
    Passport::actingAs($user);

    $this->get('api/categories')
        ->assertSuccessful()
        ->assertJsonCount(5)
        ->assertJsonPaths('*.user_id', $user->id)
        ->assertJsonStructure([
            [
                'id',
                'name',
                'type',
            ],
        ]);
}

4.php

<?php

// add this method to your TestCase
public function passportAs($user, $scopes = [], $guard = 'api')
{
    Passport::actingAs($user, $scopes, $guard);

    return $this;
}

// then refacor the test again
public function test_users_can_get_their_categories_list()
{
    factory(Category::class, 5)->create();
    $user = factory(User::class)->create();
    
    $this->passportAs($user)
        // if you did not use passport scope you can also use this
        // ->actingAs($user,'api')
        ->get('api/categories')
        ->assertSuccessful()
        ->assertJsonCount(5)
        ->assertJsonPaths('*.user_id', $user->id)
        ->assertJsonStructure([
            [
                'id',
                'name',
                'type',
            ],
        ]);
}

5.php

<?php

// Option 1, write a simple comment
public function test_users_can_get_their_categories_list()
{
    factory(Category::class, 5)->create();
    // once the user created, we will have a copy of the default categories
    $user = factory(User::class)->create();
    
    // ...
}

// Option 2, use the test dependancy feature that PHPUnit provide.

/**
 * @depends test_user_have_a_copy_of_the_default_categories
 */
public function test_users_can_get_their_categories_list()
{
    factory(Category::class, 5)->create();
    $user = factory(User::class)->create();
    
    // ...
}

6.php

<?php

/**
 * @depends test_user_have_a_copy_of_the_default_categories
 */
public function test_users_can_get_their_categories_list()
{
    factory(Category::class, 5)->create();

    $this->passportAs($user = factory(User::class)->create())
        ->get('api/categories')
        ->assertSuccessful()
        ->assertJsonCount(5)
        ->assertJsonPaths('*.user_id', $user->id)
        ->assertJsonStructure([
            [
                'id',
                'name',
                'type',
            ],
        ]);
}