Add a basic Cache driver for rollout

Author: Jaspaul

config/rollout.php

@@ -10,9 +10,9 @@
     | This option controls the default location where we'll store the data
     | used by rollout.
     |
-    | Supported: "database", "null"
+    | Supported: "cache"
     |
     */
-    'driver' => env('ROLLOUT_DRIVER', 'database')
+    'driver' => env('ROLLOUT_DRIVER', 'cache')
 
 ];

src/Drivers/Cache.php

@@ -0,0 +1,87 @@
+<?php
+
+namespace Jaspaul\LaravelRollout\Drivers;
+
+use Illuminate\Contracts\Cache\Store;
+use Opensoft\Rollout\Storage\StorageInterface;
+
+class Cache implements StorageInterface
+{
+    /**
+     * An instance of a cache store that we can store our keys in.
+     *
+     * @var \Illuminate\Contracts\Cache\Store;
+     */
+    protected $store;
+
+    /**
+     * The prefix for the cache key.
+     *
+     * @var string
+     */
+    protected $prefix;
+
+    /**
+     * Configures our cache driver with an instance of the cache store and a key
+     * prefix.
+     *
+     * @param \Illuminate\Contracts\Cache\Store $store
+     *        An instance of the cache store.
+     * @param string $prefix
+     *        A prefix for the cache keys.
+     */
+    public function __construct(Store $store, string $prefix = 'rollout')
+    {
+        $this->store = $store;
+        $this->prefix = $prefix;
+    }
+
+    /**
+     * Get's the value corresponding to the provided key from the cache. Note
+     * this function has the side effect of prepending the local prefix to the
+     * key.
+     *
+     * @param string $key
+     *        The key for the cached item.
+     *
+     * @return string|null
+     *         Null if the value is not found
+     */
+    public function get($key)
+    {
+        $key = sprintf('%s.%s', $this->prefix, $key);
+        return $this->store->get($key);
+    }
+
+    /**
+     * Store the provided key in the underlying cache layer. Note this function
+     * has the side effect of prepending the local prefix to the ky.
+     *
+     * @param string $key
+     *        The key to store the cache under.
+     * @param string $value
+     *        The value to bind to the key.
+     *
+     * @return void
+     */
+    public function set($key, $value)
+    {
+        $key = sprintf('%s.%s', $this->prefix, $key);
+        $this->store->forever($key, $value);
+    }
+
+    /**
+     * Removes the given key from the cache. Note this will handle prefixing the
+     * key before removal.
+     *
+     * @param string $key
+     *        The key to remove.
+     *
+     * @return void
+     */
+    public function remove($key)
+    {
+        $key = sprintf('%s.%s', $this->prefix, $key);
+        $this->store->forget($key);
+    }
+}

tests/Drivers/CacheTest.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Tests;
+
+use Mockery;
+use Tests\TestCase;
+use Illuminate\Cache\ArrayStore;
+use Jaspaul\LaravelRollout\Drivers\Cache;
+
+class CacheTest extends TestCase
+{
+    private $prefix = 'testing';
+
+    private $store;
+    private $cache;
+
+    /**
+     * @before
+     */
+    function setup_cache()
+    {
+        $this->store = new ArrayStore();
+        $this->cache = new Cache($this->store, $this->prefix);
+    }
+
+    /**
+     * @test
+     */
+    function ensure_the_cache_can_be_constructed()
+    {
+        $this->assertInstanceOf(Cache::class, $this->cache);
+    }
+
+    /**
+     * @test
+     */
+    function get_returns_null_if_the_cache_does_not_have_the_requested_key()
+    {
+        $this->assertNull($this->cache->get('key'));
+    }
+
+    /**
+     * @test
+     */
+    function once_set_you_can_get_the_value_back_with_the_same_key()
+    {
+        $key = 'key';
+        $value = 'value';
+
+        $this->cache->set($key, $value);
+        $this->assertSame($value, $this->cache->get($key));
+    }
+
+    /**
+     * @test
+     */
+    function once_you_remove_a_value_you_will_not_be_able_to_retrieve_it_from_the_store()
+    {
+        $key = 'key';
+        $value = 'value';
+
+        $this->cache->set($key, $value);
+        $this->assertSame($value, $this->cache->get($key));
+
+        $this->cache->remove($key);
+        $this->assertNull($this->cache->get($key));
+    }
+}