TIDE/backend/tests/Unit/Comment/UseCases/ListCommentsForPostTest.php

<?php

namespace Tests\Unit\Comment\UseCases;

use App\Comment\CreateCommentDto;
use App\Comment\UseCases\ListCommentsForPost\ListCommentsForPost;
use App\Comment\UseCases\ListCommentsForPost\ListCommentsForPostRequest;
use App\Exceptions\BadRequestException;
use DateTimeImmutable;
use DateTimeZone;
use Tests\Fakes\FakeCommentRepository;
use Tests\TestCase;

class ListCommentsForPostTest extends TestCase
{
    private FakeCommentRepository $commentRepo;

    private ListCommentsForPost $useCase;

    private DateTimeImmutable $now;

    protected function setUp(): void
    {
        $this->now = new DateTimeImmutable(
            '2026-05-06T12:00:00',
            new DateTimeZone('UTC'),
        );
        $this->commentRepo = new FakeCommentRepository;
        $this->useCase = new ListCommentsForPost($this->commentRepo);
    }

    private function seedComment(int $postId, string $body, string $offset): void
    {
        $this->commentRepo->create(new CreateCommentDto(
            postId: $postId,
            userId: 1,
            body: $body,
            createdAt: $this->now->modify($offset),
        ));
    }

    public function test_zero_post_id_throws_bad_request(): void
    {
        $this->expectException(BadRequestException::class);
        $this->useCase->execute(new ListCommentsForPostRequest(
            postId: 0,
        ));
    }

    public function test_returns_empty_list_when_no_comments(): void
    {
        $result = $this->useCase->execute(new ListCommentsForPostRequest(
            postId: 1,
        ));

        $this->assertSame([], $result);
    }

    public function test_returns_only_comments_for_given_post(): void
    {
        $this->seedComment(1, 'first', '+0 seconds');
        $this->seedComment(2, 'other-post', '+0 seconds');
        $this->seedComment(1, 'second', '+1 minute');

        $result = $this->useCase->execute(new ListCommentsForPostRequest(
            postId: 1,
        ));

        $this->assertCount(2, $result);
        $this->assertSame('first', $result[0]->getBody());
        $this->assertSame('second', $result[1]->getBody());
    }
}