67.重构

TDD 构建 Laravel 论坛笔记 /

本系列文章为laracasts.com 的系列视频教程——Let's Build A Forum with Laravel and TDD 的学习笔记。若喜欢该系列视频，可去该网站订阅后下载该系列视频， 支持正版 ；

视频源码地址：github.com/laracasts/Lets-Build-a-...；

本项目为一个 forum（论坛）项目，与本站的第二本实战教程《Laravel 教程 - Web 开发实战进阶》类似，可互相参照。

本节说明

对应视频教程第 67 小节：Isolating Knowledge

本节内容

上一节我们利用 Redis 存储了热门话题的信息，这一节我们来做点重构。我们新建一个类文件，将存储和读取缓存的逻辑抽取出来：
forum\app\Trending.php

<?php

namespace App;

use Illuminate\Support\Facades\Redis;

class Trending
{
    public function get()
    {
        return array_map('json_decode',Redis::zrevrange('trending_threads',0,4));
    }

    public function push($thread)
    {
        Redis::zincrby('trending_threads',1,json_encode([
            'title' => $thread->title,
            'path' => $thread->path()
        ]));
    }
}

现在我们可以修改控制器：
forum\app\Http\Controllers\ThreadsController.php

<?php

namespace App\Http\Controllers;

use App\Trending;
.
.
class ThreadsController extends Controller
{
    .
    .
    public function index(Channel $channel,ThreadsFilters $filters,Trending $trending)
    {
        $threads = $this->getThreads($channel, $filters);

        if(request()->wantsJson()){
            return $threads;
        }

        return view('threads.index',[
            'threads' => $threads,
            'trending' => $trending->get()
        ]);
    }
    .
    .
    public function show($channel,Thread $thread,Trending $trending)
    {
        if(auth()->check()){
            auth()->user()->read($thread);
        }

        $trending->push($thread);

        return view('threads.show',compact('thread'));
    }
    .
    .
}

运行测试：
file
现在有点小问题要考虑：我们在测试环境和开发环境使用了相同的键来存储缓存。如果你不介意这样做，当然也可以。但是我们仍然来做点重构：
forum\app\Trending.php

<?php

namespace App;

use Illuminate\Support\Facades\Redis;

class Trending
{
    public function get()
    {
        return array_map('json_decode',Redis::zrevrange($this->cacheKey(),0,4));
    }

    public function push($thread)
    {
        Redis::zincrby($this->cacheKey(),1,json_encode([
            'title' => $thread->title,
            'path' => $thread->path()
        ]));
    }

    public function cacheKey()
    {
        return app()->environment('testing') ? 'testing_trending_threads' : 'trending_threads';
    }

    public function reset()
    {
        Redis::del($this->cacheKey());
    }
}

我们通过cacheKey()方法，根据不同环境获取不同键名，然后获取或者删除不同环境的缓存。我们来相应修改测试：
forum\tests\Feature\TrendingThreadsTest.php

<?php

namespace Tests\Feature;

use App\Trending;
use Tests\TestCase;
use Illuminate\Foundation\Testing\DatabaseMigrations;

class TrendingThreadsTest extends TestCase
{
    use DatabaseMigrations;

    protected function setUp()
    {
        parent::setUp();

        $this->trending = new Trending();

        $this->trending->reset();
    }

    /** @test */
    public function it_increments_a_thread_score_each_time_it_is_read()
    {
        $this->assertEmpty($this->trending->get());

        $thread = create('App\Thread');

        $this->call('GET',$thread->path());

        $this->assertCount(1,$trending = $this->trending->get());

        $this->assertEquals($thread->title,$trending[0]->title);
    }
}

我们来运行该测试：
file
运行全部测试：
file