Add unit tests for file thumbnail generation

Summary: Fixes T12614.

Test Plan:
  - Ran tests, saw them pass.
  - Changed a thumbnail to 800x800, saw tests detect that the default image was missing.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12614

Differential Revision: https://secure.phabricator.com/D17773

src/applications/files/transform/__tests__/PhabricatorFileTransformTestCase.php

@@ -2,9 +2,33 @@
 
 final class PhabricatorFileTransformTestCase extends PhabricatorTestCase {
 
+  protected function getPhabricatorTestCaseConfiguration() {
+    return array(
+      self::PHABRICATOR_TESTCONFIG_BUILD_STORAGE_FIXTURES => true,
+    );
+  }
+
   public function testGetAllTransforms() {
     PhabricatorFileTransform::getAllTransforms();
     $this->assertTrue(true);
   }
 
+  public function testThumbTransformDefaults() {
+    $xforms = PhabricatorFileTransform::getAllTransforms();
+    $file = new PhabricatorFile();
+
+    foreach ($xforms as $xform) {
+      if (!($xform instanceof PhabricatorFileThumbnailTransform)) {
+        continue;
+      }
+
+      // For thumbnails, generate the default thumbnail. This should be able
+      // to generate something rather than throwing an exception because we
+      // forgot to add a default file to the builtin resources. See T12614.
+      $xform->getDefaultTransform($file);
+
+      $this->assertTrue(true);
+    }
+  }
+
 }