Mock test for attachment retrieval

tests/OfflineTests/ObjectRetrieverMockTest.php

@@ -17,12 +17,14 @@ class ObjectRetrieverMockTest extends \PHPUnit\Framework\TestCase {
     private $retriever;
 
     /**
-     * @param Response|\Throwable $response A response, or an exception to throw instead.
+     * @param Response|\Throwable ...$responses Responses in the order they are returned,
+     *  or exceptions to throw instead.
      */
-    private function setMockResponse($response) {
+    private function setMockResponse(...$responses) : MockHandler {
-        $mock = new MockHandler([$response]);
+        $mock = new MockHandler($responses);
         $handler = HandlerStack::create($mock);
         $this->retriever->setClient(new Client(['handler' => $handler]));
+        return $mock;
     }
 
     protected function setUp(): void {
@@ -90,6 +92,29 @@ class ObjectRetrieverMockTest extends \PHPUnit\Framework\TestCase {
         }
     }
 
+    public function testGetAttachment() {
+        $mock = $this->setMockResponse(
+            new Response(200, ['Content-Type' => 'application/ld+json'],
+                '{"@id":"coid://cloudobjects.io/Test","coid://cloudobjects.io/isAtRevision":"1-abc"}'),
+            new Response(200, ['Content-Type' => 'text/plain'], 'Attachment content')
+        );
+
+        $content = $this->retriever->getAttachment(new IRI('coid://cloudobjects.io/Test'), 'file.txt');
+        $this->assertEquals('Attachment content', $content);
+        $this->assertStringEndsWith('cloudobjects.io/Test/file.txt', $mock->getLastRequest()->getUri()->getPath());
+    }
+
+    public function testGetMissingAttachment() {
+        $this->setMockResponse(
+            new Response(200, ['Content-Type' => 'application/ld+json'],
+                '{"@id":"coid://cloudobjects.io/Test","coid://cloudobjects.io/isAtRevision":"1-abc"}'),
+            new Response(404)
+        );
+
+        $content = $this->retriever->getAttachment(new IRI('coid://cloudobjects.io/Test'), 'missing.txt');
+        $this->assertNull($content);
+    }
+
     private function createFallbackStoreDirectory() : string {
         $directory = sys_get_temp_dir().DIRECTORY_SEPARATOR.'clobj-fallback-'.uniqid();
         mkdir($directory);