PHPUnit 自動化測試大作戰【CH17】

今天讓我們回顧一下前一天的 Mocking 初體驗吧！

Mocking 初體驗回顧

• app/Repositories/UserRepository.php

<?php

namespace App\Repositories;

use App\Models\User;

class UserRepository{

    protected $model;

    public function __construct(User $model)    {

        $this->model = $model;

    }    public function getUserById($userId)    {

        return $this->model::find($userId);

    }} 

• app/Repositories/PostRepository.php

<?php

namespace App\Repositories;

class PostRepository{

    protected $model;

}

• app/Services/UserService.php

<?php

namespace App\Services;

use App\Repositories\PostRepository;

use App\Repositories\UserRepository;

class UserService{

    private $userRepository;

    private $postRepository;

    public function __construct(        PostRepository $postRepository,        UserRepository $userRepository    ) {

        $this->postRepository = $postRepository;

        $this->userRepository = $userRepository;

    }    public function getUserData(int $userId)    {

        $user = $this->userRepository->getUserById($userId);

        if (empty($user)) {

            return [];

        }        $user->posts = $this->postRepository->getPostsByUserId($userId);

        return $user;

    }} 

• tests/Feature/UserServiceTest.php

<?php

namespace Tests\Feature;

use App\Models\User;

use App\Repositories\PostRepository;

use App\Repositories\UserRepository;

use App\Services\UserService;

use Tests\TestCase;

class UserServiceTest extends TestCase{

    public function testGetUserDataWhenUserNotFound()    {

        $this->mock(UserRepository::class, function ($mock) {

            $mock->shouldReceive('getUserById')

        ->with(1)

                ->once()

                ->andReturn(null);

        });        $service = app(UserService::class);

        $user = $service->getUserData(1);

        $this->assertEmpty($user);

    }    public function testGetUserData()    {

        $user = User::factory()->make();

        $this->mock(UserRepository::class, function ($mock) use ($user) {

            $mock->shouldReceive('getUserById')

        ->with(1)

                ->once()

                ->andReturn($user);

        });        $this->mock(PostRepository::class, function ($mock) {

            $mock->shouldReceive('getPostsByUserId')

        ->with(1)

                ->once()

                ->andReturn([]);

        });        $service = app(UserService::class);

        $user = $service->getUserData(1);

        $this->assertNotEmpty($user);

        $this->assertNotNull($user->posts);

    }}

在前一天的 Mocking 初體驗中，我們有用到4個重要的 Mocking 函數，以下就針對它們做個簡單介紹吧！

Mocking 函數說明

• shouldReceive()：當我們預期指定類別的某個函數，會在測試過程被呼叫，且希望 Mock 此函數的行為時，我們就會用到 shouldReceive()來補捉這個呼叫行為，並且接著 Mock 該函數後續的行為。
• with()：此函數通常會接在shouldReceive()之後，用以補捉符合某種輸入參數組合的函數呼叫，並接著 Mock 該函數後續的行為。
• once()：此函數通常會接在with()之後，用以補捉只呼叫一次的函數呼叫，並接著 Mock 該函數後續的行為。
• andReturn()：此函數通常會接在with()或once之後，用以 Mock 函數的回應值。

測試案例導覽

• testGetUserDataWhenUserNotFound()

$this->mock(UserRepository::class, function ($mock) {

    $mock->shouldReceive('getUserById')

    ->with(1)

        ->once()        ->andReturn(null);});$service = app(UserService::class);

$user = $service->getUserData(1);

$this->assertEmpty($user);

在此案例中，我們 Mock 了 UserRepository 這個類別，並且補捉 getUserById() 的 1次性函數呼叫，且此呼叫附帶的函數呼叫參數是 1，接著我們 Mock 它的回應為 null。

• testGetUserData()

 $user = User::factory()->make();

$this->mock(UserRepository::class, function ($mock) use ($user) {

    $mock->shouldReceive('getUserById')

    ->with(1)

        ->once()        ->andReturn($user);

});$this->mock(PostRepository::class, function ($mock) {

    $mock->shouldReceive('getPostsByUserId')

    ->with(1)

        ->once()        ->andReturn([]);});$service = app(UserService::class);

$user = $service->getUserData(1);

$this->assertNotEmpty($user);

$this->assertNotNull($user->posts);

在此案例中，我們同樣 Mock 了 UserRepository 這個類別，並且補捉 getUserById() 的 1次性函數呼叫，且此呼叫附帶的函數呼叫參數是 1，接著我們 Mock 它的回應為前面所建立的測試資料 $user。同時我們還 Mock 了 PostRepository 這個類別，並且補捉 getPostsByUserId() 的 1次性函數呼叫，且此呼叫附帶的函數呼叫參數是 1，接著我們 Mock 它的回應為空陣列 []。

以上就是今天的回顧，希望有讓大家更了解 Mocking 的實際作法。

另外值得一題的是，這4個函數也算是一種 Assertion 函數，因此在跑完測試後，顯示的測試 Assertion 數，是有包含這幾個函數被執行的次數的。

下一篇繼續來探討 Mocking。

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參考資料

• https://laravel.com/docs/9.x/mocking#storage-fake

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