Testing for empty body on cache hit

Adding tests ETag and Last-Modified to ensure the
response body shouldn't send data when their is a
cache hit.

Author: JimTools

tests/CacheTest.php

@@ -16,11 +16,18 @@
 use Slim\Psr7\Factory\ResponseFactory;
 use Slim\Psr7\Factory\ServerRequestFactory;
 
+use Slim\Psr7\Factory\StreamFactory;
 use function gmdate;
 use function time;
 
 class CacheTest extends TestCase
 {
+    private function createCache(string $type = 'privte', int $maxAge = 86400, bool $mustRevalidate = false): Cache
+    {
+        return new Cache(new StreamFactory(), $type, $maxAge, $mustRevalidate);
+    }
+
+
     public function requestFactory(): ServerRequestInterface
     {
         $serverRequestFactory = new ServerRequestFactory();
@@ -64,7 +71,7 @@ public function handle(ServerRequestInterface $request): ResponseInterface
 
     public function testCacheControlHeader()
     {
-        $cache = new Cache('public', 86400);
+        $cache = $this->createCache('public', 86400);
         $req = $this->requestFactory();
 
         $res = $cache->process($req, $this->createRequestHandler());
@@ -76,7 +83,7 @@ public function testCacheControlHeader()
 
     public function testCacheControlHeaderWithMustRevalidate()
     {
-        $cache = new Cache('private', 86400, true);
+        $cache = $this->createCache('private', 86400, true);
         $req = $this->requestFactory();
 
         $res = $cache->process($req, $this->createRequestHandler());
@@ -88,7 +95,7 @@ public function testCacheControlHeaderWithMustRevalidate()
 
     public function testCacheControlHeaderWithZeroMaxAge()
     {
-        $cache = new Cache('private', 0, false);
+        $cache = $this->createCache('private', 0, false);
         $req = $this->requestFactory();
 
         $res = $cache->process($req, $this->createRequestHandler());
@@ -100,7 +107,7 @@ public function testCacheControlHeaderWithZeroMaxAge()
 
     public function testCacheControlHeaderDoesNotOverrideExistingHeader()
     {
-        $cache = new Cache('public', 86400);
+        $cache =  $this->createCache('public', 86400);
         $req = $this->requestFactory();
 
         $res = $this->createResponse()->withHeader('Cache-Control', 'no-cache,no-store');
@@ -116,7 +123,7 @@ public function testLastModifiedWithCacheHit()
         $now = time();
         $lastModified = gmdate('D, d M Y H:i:s T', $now + 86400);
         $ifModifiedSince = gmdate('D, d M Y H:i:s T', $now + 86400);
-        $cache = new Cache('public', 86400);
+        $cache =  $this->createCache('public', 86400);
 
         $req = $this->requestFactory()->withHeader('If-Modified-Since', $ifModifiedSince);
 
@@ -131,7 +138,7 @@ public function testLastModifiedWithCacheHitAndNewerDate()
         $now = time();
         $lastModified = gmdate('D, d M Y H:i:s T', $now + 86400);
         $ifModifiedSince = gmdate('D, d M Y H:i:s T', $now + 172800); // <-- Newer date
-        $cache = new Cache('public', 86400);
+        $cache = $this->createCache('public', 86400);
         $req = $this->requestFactory()->withHeader('If-Modified-Since', $ifModifiedSince);
 
         $res = $this->createResponse()->withHeader('Last-Modified', $lastModified);
@@ -145,7 +152,7 @@ public function testLastModifiedWithCacheHitAndOlderDate()
         $now = time();
         $lastModified = gmdate('D, d M Y H:i:s T', $now + 86400);
         $ifModifiedSince = gmdate('D, d M Y H:i:s T', $now); // <-- Older date
-        $cache = new Cache('public', 86400);
+        $cache =  $this->createCache('public', 86400);
         $req = $this->requestFactory()->withHeader('If-Modified-Since', $ifModifiedSince);
 
         $res = $this->createResponse()->withHeader('Last-Modified', $lastModified);
@@ -159,7 +166,7 @@ public function testLastModifiedWithCacheMiss()
         $now = time();
         $lastModified = gmdate('D, d M Y H:i:s T', $now + 86400);
         $ifModifiedSince = gmdate('D, d M Y H:i:s T', $now - 86400);
-        $cache = new Cache('public', 86400);
+        $cache = $this->createCache('public', 86400);
         $req = $this->requestFactory()->withHeader('If-Modified-Since', $ifModifiedSince);
 
         $res = $this->createResponse()->withHeader('Last-Modified', $lastModified);
@@ -172,7 +179,7 @@ public function testETagWithCacheHit()
     {
         $etag = 'abc';
         $ifNoneMatch = 'abc';
-        $cache = new Cache('public', 86400);
+        $cache =  $this->createCache('public', 86400);
         $req = $this->requestFactory()->withHeader('If-None-Match', $ifNoneMatch);
 
         $res = $this->createResponse()->withHeader('Etag', $etag);
@@ -185,12 +192,43 @@ public function testETagWithCacheMiss()
     {
         $etag = 'abc';
         $ifNoneMatch = 'xyz';
-        $cache = new Cache('public', 86400);
+        $cache =  $this->createCache('public', 86400);
         $req = $this->requestFactory()->withHeader('If-None-Match', $ifNoneMatch);
 
         $res = $this->createResponse()->withHeader('Etag', $etag);
         $res = $cache->process($req, $this->createRequestHandler($res));
 
         $this->assertEquals(200, $res->getStatusCode());
     }
+
+    public function testETagReturnsNoBodyOnCacheHit(): void
+    {
+        $etag = 'abc';
+        $cache =  $this->createCache();
+        $req = $this->requestFactory()->withHeader('If-None-Match', $etag);
+
+        $res = $this->createResponse()->withHeader('Etag', $etag);
+        $res->getBody()->write('payload data');
+        $res = $cache->process($req, $this->createRequestHandler($res));
+
+        self::assertSame(304, $res->getStatusCode());
+        self::assertSame('', (string) $res->getBody());
+    }
+
+    public function testLastModifiedReturnsNoBodyOnCacheHit(): void
+    {
+        $now = time() + 86400;
+        $lastModified = gmdate('D, d M Y H:i:s T', $now);
+        $ifModifiedSince = gmdate('D, d M Y H:i:s T', $now);
+        $cache = $this->createCache();
+
+        $req = $this->requestFactory()->withHeader('If-Modified-Since', $ifModifiedSince);
+        $res = $this->createResponse()->withHeader('Last-Modified', $lastModified);
+        $res->getBody()->write('payload data');
+
+        $res = $cache->process($req, $this->createRequestHandler($res));
+
+        self::assertEquals(304, $res->getStatusCode());
+        self::assertSame('', (string) $res->getBody());
+    }
 }