Split checking of static cache vs getting it (#3255)

src/StaticCaching/Cacher.php

@@ -14,6 +14,14 @@ interface Cacher
      */
     public function cachePage(Request $request, $content);
 
+    /**
+     * Check if a page has been cached.
+     *
+     * @param Request $request
+     * @return bool
+     */
+    public function hasCachedPage(Request $request);
+
     /**
      * Get a cached page.
      *

src/StaticCaching/Cachers/AbstractCacher.php

@@ -274,4 +274,9 @@ protected function getUrlsCacheKey($domain = null)
 
         return $this->normalizeKey($this->makeHash($domain).'.urls');
     }
+
+    public function hasCachedPage(Request $request)
+    {
+        return $this->getCachedPage($request) !== null;
+    }
 }

src/StaticCaching/Cachers/ApplicationCacher.php

@@ -11,6 +11,11 @@ class ApplicationCacher extends AbstractCacher
      */
     protected $cache;
 
+    /**
+     * @var string|null
+     */
+    private $cached;
+
     /**
      * Cache a page.
      *
@@ -42,13 +47,29 @@ public function cachePage(Request $request, $content)
         }
     }
 
+    /**
+     * Check if a page has been cached.
+     *
+     * @param Request $request
+     * @return bool
+     */
+    public function hasCachedPage(Request $request)
+    {
+        return (bool) $this->cached = $this->getFromCache($request);
+    }
+
     /**
      * Get a cached page.
      *
      * @param Request $request
      * @return string
      */
     public function getCachedPage(Request $request)
+    {
+        return $this->cached ?? $this->getFromCache($request);
+    }
+
+    private function getFromCache(Request $request)
     {
         $url = $this->getUrl($request);
 

src/StaticCaching/Cachers/FileCacher.php

@@ -63,6 +63,13 @@ public function getCachedPage(Request $request)
         return File::get($this->getFilePath($url));
     }
 
+    public function hasCachedPage(Request $request)
+    {
+        $url = $this->getUrl($request);
+
+        return File::exists($this->getFilePath($url));
+    }
+
     /**
      * Flush out the entire static cache.
      *

src/StaticCaching/Cachers/NullCacher.php

@@ -12,6 +12,11 @@ public function cachePage(Request $request, $content)
         //
     }
 
+    public function hasCachedPage(Request $request)
+    {
+        return false;
+    }
+
     public function getCachedPage(Request $request)
     {
         //

src/StaticCaching/Middleware/Cache.php

@@ -27,8 +27,8 @@ public function __construct(Cacher $cacher)
      */
     public function handle($request, Closure $next)
     {
-        if ($this->canBeCached($request) && ($cached = $this->cacher->getCachedPage($request))) {
-            return response($cached);
+        if ($this->canBeCached($request) && $this->cacher->hasCachedPage($request)) {
+            return response($this->cacher->getCachedPage($request));
         }
 
         $response = $next($request);

tests/StaticCaching/ApplicationCacherTest.php

@@ -9,14 +9,46 @@
 
 class ApplicationCacherTest extends TestCase
 {
+    /** @test */
+    public function it_checks_if_a_page_is_cached()
+    {
+        $key = 'static-cache:responses:'.md5('http://example.com/test?foo=bar');
+        $cache = $this->mock(Repository::class);
+        $cache->shouldReceive('get')->with($key)->times(2)->andReturn(null, 'html content');
+        $cache->shouldNotReceive('has');
+
+        $cacher = new ApplicationCacher($cache, []);
+        $request = Request::create('http://example.com/test', 'GET', ['foo' => 'bar']);
+
+        $this->assertFalse($cacher->hasCachedPage($request));
+        $this->assertTrue($cacher->hasCachedPage($request));
+    }
+
     /** @test */
     public function gets_cached_page()
     {
-        $cache = app(Repository::class);
+        $key = 'static-cache:responses:'.md5('http://example.com/test?foo=bar');
+        $cache = $this->mock(Repository::class);
+        $cache->shouldReceive('get')->with($key)->once()->andReturn('html content');
+
+        $cacher = new ApplicationCacher($cache, []);
+        $request = Request::create('http://example.com/test', 'GET', ['foo' => 'bar']);
+
+        $this->assertEquals('html content', $cacher->getCachedPage($request));
+    }
+
+    /** @test */
+    public function checking_if_page_is_cached_then_retrieving_it_will_only_hit_the_cache_once()
+    {
+        $key = 'static-cache:responses:'.md5('http://example.com/test?foo=bar');
+        $cache = $this->mock(Repository::class);
+        $cache->shouldReceive('get')->with($key)->once()->andReturn('html content');
+        $cache->shouldNotReceive('has');
+
         $cacher = new ApplicationCacher($cache, []);
-        $cache->forever('static-cache:responses:'.md5('http://example.com/test?foo=bar'), 'html content');
         $request = Request::create('http://example.com/test', 'GET', ['foo' => 'bar']);
 
+        $this->assertTrue($cacher->hasCachedPage($request));
         $this->assertEquals('html content', $cacher->getCachedPage($request));
     }