FIX Ensure manipulations start with base file (silverstripe#612)

It turns out there's some special logic going on in manipulation that
needs to take place starting with the File record. If you try to use the
DBFile on its own without first performin a manipulation, the attributes
applied to the file won't be passed down to subsequent manipulations.

src/Conversion/FileConverter.php

@@ -2,6 +2,7 @@
 
 namespace SilverStripe\Assets\Conversion;
 
+use SilverStripe\Assets\File;
 use SilverStripe\Assets\Storage\DBFile;
 
 /**
@@ -27,5 +28,5 @@ public function supportsConversion(string $fromExtension, string $toExtension, a
      * @param array $options Any options defined for this converter which should apply to the conversion.
      * @throws FileConverterException if invalid options are passed, or the conversion is not supported or fails.
      */
-    public function convert(DBFile $from, string $toExtension, array $options = []): DBFile;
+    public function convert(DBFile|File $from, string $toExtension, array $options = []): DBFile;
 }

src/Conversion/FileConverterManager.php

@@ -2,6 +2,7 @@
 
 namespace SilverStripe\Assets\Conversion;
 
+use SilverStripe\Assets\File;
 use SilverStripe\Assets\Storage\DBFile;
 use SilverStripe\Core\Config\Configurable;
 use SilverStripe\Core\Injector\Injector;
@@ -27,7 +28,7 @@ class FileConverterManager
      * Note that if a converter supports the conversion generally but doesn't support these options, that converter will not be used.
      * @throws FileConverterException if the conversion failed or there were no converters available.
      */
-    public function convert(DBFile $from, string $toExtension, array $options = []): DBFile
+    public function convert(DBFile|File $from, string $toExtension, array $options = []): DBFile
     {
         $fromExtension = $from->getExtension();
         foreach (static::config()->get('converters') as $converterClass) {

src/Conversion/InterventionImageFileConverter.php

@@ -4,6 +4,7 @@
 
 use Imagick;
 use Intervention\Image\Exception\ImageException;
+use SilverStripe\Assets\File;
 use SilverStripe\Assets\Image_Backend;
 use SilverStripe\Assets\InterventionBackend;
 use SilverStripe\Assets\Storage\AssetStore;
@@ -33,7 +34,7 @@ public function supportsConversion(string $fromExtension, string $toExtension, a
         return $this->supportedByIntervention($fromExtension, $backend) && $this->supportedByIntervention($toExtension, $backend);
     }
 
-    public function convert(DBFile $from, string $toExtension, array $options = []): DBFile
+    public function convert(DBFile|File $from, string $toExtension, array $options = []): DBFile
     {
         // Do some basic validation up front for things we know aren't supported
         $problems = $this->validateOptions($options);

src/ImageManipulation.php

@@ -721,13 +721,8 @@ public function ThumbnailURL($width, $height)
     public function Convert(string $toExtension): ?AssetContainer
     {
         $converter = Injector::inst()->get(FileConverterManager::class);
-        if ($this instanceof File) {
-            $from = $this->File;
-        } elseif ($this instanceof DBFile) {
-            $from = $this;
-        }
         try {
-            return $converter->convert($from, $toExtension);
+            return $converter->convert($this, $toExtension);
         } catch (FileConverterException $e) {
             /** @var LoggerInterface $logger */
             $logger = Injector::inst()->get(LoggerInterface::class . '.errorhandler');

tests/php/Conversion/FileConversionManagerTest/TestImageConverter.php

@@ -15,9 +15,9 @@ public function supportsConversion(string $fromExtension, string $toExtension, a
         return in_array($fromExtension, $formats) && in_array($toExtension, $formats);
     }
 
-    public function convert(DBFile $from, string $toExtension, array $options = []): DBFile
+    public function convert(DBFile|File $from, string $toExtension, array $options = []): DBFile
     {
-        $result = clone $from;
+        $result = ($from instanceof File) ? clone $from->File : clone $from;
         $result->Filename = 'converted.' . $toExtension;
         return $result;
     }

tests/php/Conversion/FileConversionManagerTest/TestTxtToImageConverter.php

@@ -15,9 +15,9 @@ public function supportsConversion(string $fromExtension, string $toExtension, a
         return strtolower($fromExtension) === 'txt' && in_array(strtolower($toExtension), $formats);
     }
 
-    public function convert(DBFile $from, string $toExtension, array $options = []): DBFile
+    public function convert(DBFile|File $from, string $toExtension, array $options = []): DBFile
     {
-        $result = clone $from;
+        $result = ($from instanceof File) ? clone $from->File : clone $from;
         $result->Filename = 'converted.' . $toExtension;
         return $result;
     }

tests/php/ImageManipulationTest.php

@@ -7,6 +7,7 @@
 use Psr\Log\LoggerInterface;
 use SilverStripe\Assets\Conversion\FileConverterException;
 use SilverStripe\Assets\Conversion\FileConverterManager;
+use SilverStripe\Assets\Conversion\InterventionImageFileConverter;
 use Silverstripe\Assets\Dev\TestAssetStore;
 use SilverStripe\Assets\File;
 use SilverStripe\Assets\FilenameParsing\AbstractFileIDHelper;
@@ -604,4 +605,27 @@ public function testConvert(string $originalFileFixtureClass, string $originalFi
             $this->assertNull($result);
         }
     }
+
+    public function provideConvertChainWithLazyLoad(): array
+    {
+        return [
+            [true],
+            [false],
+        ];
+    }
+
+    /**
+     * @dataProvider provideConvertChainWithLazyLoad
+     */
+    public function testConvertChainWithLazyLoad(bool $lazyLoad): void
+    {
+        // Make sure we have a known set of converters for testing
+        FileConverterManager::config()->set('converters', [InterventionImageFileConverter::class]);
+        $file = $this->objFromFixture(Image::class, 'imageWithTitle');
+        /** @var DBFile */
+        $result = $file->LazyLoad($lazyLoad)->Convert('webp');
+        $this->assertSame($lazyLoad, $result->IsLazyLoaded());
+        $result = $file->Convert('webp')->LazyLoad($lazyLoad);
+        $this->assertSame($lazyLoad, $result->IsLazyLoaded());
+    }
 }