67.重构

• 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：

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：

运行全部测试：