ENGCOM-5612: Handle the error properly when LESS source file is empty or having compilation error, and make the error message clear and clean. #22182

 - Merge Pull Request #22182 from Hailong/magento2:empty-less-source-error-handling
 - Merged commits:
   1. 517788a
   2. e54c7f7
   3. b4a7ca4

Author: magento-engcom-team

app/code/Magento/Deploy/Package/Package.php

@@ -150,6 +150,8 @@ public function __construct(
     }
 
     /**
+     * Get area.
+     *
      * @return string
      */
     public function getArea()
@@ -158,6 +160,8 @@ public function getArea()
     }
 
     /**
+     * Get parent.
+     *
      * @return Package
      */
     public function getParent()
@@ -166,6 +170,8 @@ public function getParent()
     }
 
     /**
+     * Get theme.
+     *
      * @return string
      */
     public function getTheme()
@@ -174,6 +180,8 @@ public function getTheme()
     }
 
     /**
+     * Get locale.
+     *
      * @return string
      */
     public function getLocale()
@@ -204,6 +212,8 @@ public function isVirtual()
     }
 
     /**
+     * Get param.
+     *
      * @param string $name
      * @return mixed|null
      */
@@ -213,6 +223,8 @@ public function getParam($name)
     }
 
     /**
+     * Set param.
+     *
      * @param string $name
      * @param mixed $value
      * @return bool
@@ -320,7 +332,10 @@ public function getFilesByType($type)
      */
     public function deleteFile($fileId)
     {
+        $file = $this->files[$fileId];
+        $deployedFileId = $file->getDeployedFileId();
         unset($this->files[$fileId]);
+        unset($this->map[$deployedFileId]);
     }
 
     /**
@@ -348,6 +363,8 @@ public function aggregate(Package $parentPackage = null)
     }
 
     /**
+     * Set parent.
+     *
      * @param Package $parent
      * @return bool
      */
@@ -368,6 +385,8 @@ public function getMap()
     }
 
     /**
+     * Get state.
+     *
      * @return int
      */
     public function getState()
@@ -376,6 +395,8 @@ public function getState()
     }
 
     /**
+     * Set state.
+     *
      * @param int $state
      * @return bool
      */
@@ -386,6 +407,8 @@ public function setState($state)
     }
 
     /**
+     * Get inheritance level.
+     *
      * @return int
      */
     public function getInheritanceLevel()
@@ -422,6 +445,7 @@ public function getParentMap()
     {
         $map = [];
         foreach ($this->getParentPackages() as $parentPackage) {
+            // phpcs:ignore Magento2.Performance.ForeachArrayMerge.ForeachArrayMerge
             $map = array_merge($map, $parentPackage->getMap());
         }
         return $map;
@@ -438,8 +462,10 @@ public function getParentFiles($type = null)
         $files = [];
         foreach ($this->getParentPackages() as $parentPackage) {
             if ($type === null) {
+                // phpcs:ignore Magento2.Performance.ForeachArrayMerge.ForeachArrayMerge
                 $files = array_merge($files, $parentPackage->getFiles());
             } else {
+                // phpcs:ignore Magento2.Performance.ForeachArrayMerge.ForeachArrayMerge
                 $files = array_merge($files, $parentPackage->getFilesByType($type));
             }
         }
@@ -477,6 +503,8 @@ public function getParentPackages()
     }
 
     /**
+     * Get pre processors.
+     *
      * @return Processor\ProcessorInterface[]
      */
     public function getPreProcessors()
@@ -485,6 +513,8 @@ public function getPreProcessors()
     }
 
     /**
+     * Get post processors.
+     *
      * @return Processor\ProcessorInterface[]
      */
     public function getPostProcessors()

app/code/Magento/Deploy/Service/DeployPackage.php

@@ -134,9 +134,10 @@ public function deployEmulated(Package $package, array $options, $skipLogging =
             } catch (ContentProcessorException $exception) {
                 $errorMessage = __('Compilation from source: ')
                     . $file->getSourcePath()
-                    . PHP_EOL . $exception->getMessage();
+                    . PHP_EOL . $exception->getMessage() . PHP_EOL;
                 $this->errorsCount++;
                 $this->logger->critical($errorMessage);
+                $package->deleteFile($file->getFileId());
             } catch (\Exception $exception) {
                 $this->logger->critical(
                     'Compilation from source ' . $file->getSourcePath() . ' failed' . PHP_EOL . (string)$exception

dev/tests/integration/testsuite/Magento/Email/Model/Template/FilterTest.php

@@ -9,6 +9,7 @@
 use Magento\Framework\App\State;
 use Magento\Framework\App\TemplateTypesInterface;
 use Magento\Framework\Phrase;
+use Magento\Framework\View\Asset\ContentProcessorInterface;
 use Magento\Setup\Module\I18n\Locale;
 use Magento\Theme\Block\Html\Footer;
 
@@ -267,7 +268,7 @@ public function cssDirectiveDataProvider()
             'Empty or missing file' => [
                 TemplateTypesInterface::TYPE_HTML,
                 'file="css/non-existent-file.css"',
-                '/* Contents of the specified CSS file could not be loaded or is empty */'
+                '/*' . PHP_EOL . ContentProcessorInterface::ERROR_MESSAGE_PREFIX . 'LESS file is empty: ',
             ],
             'File with compilation error results in error message' => [
                 TemplateTypesInterface::TYPE_HTML,
@@ -407,10 +408,12 @@ public function inlinecssDirectiveThrowsExceptionWhenMissingParameterDataProvide
     protected function setUpDesignParams()
     {
         $themeCode = 'Vendor_EmailTest/custom_theme';
-        $this->model->setDesignParams([
-            'area' => Area::AREA_FRONTEND,
-            'theme' => $themeCode,
-            'locale' => Locale::DEFAULT_SYSTEM_LOCALE,
-        ]);
+        $this->model->setDesignParams(
+            [
+                'area' => Area::AREA_FRONTEND,
+                'theme' => $themeCode,
+                'locale' => Locale::DEFAULT_SYSTEM_LOCALE,
+            ]
+        );
     }
 }

lib/internal/Magento/Framework/Css/PreProcessor/Adapter/Less/Processor.php

@@ -61,7 +61,6 @@ public function __construct(
 
     /**
      * @inheritdoc
-     * @throws ContentProcessorException
      */
     public function processContent(File $asset)
     {
@@ -77,7 +76,9 @@ public function processContent(File $asset)
             $content = $this->assetSource->getContent($asset);
 
             if (trim($content) === '') {
-                return '';
+                throw new ContentProcessorException(
+                    new Phrase('Compilation from source: LESS file is empty: ' . $path)
+                );
             }
 
             $tmpFilePath = $this->temporaryFile->createFile($path, $content);
@@ -88,8 +89,9 @@ public function processContent(File $asset)
             gc_enable();
 
             if (trim($content) === '') {
-                $this->logger->warning('Parsed less file is empty: ' . $path);
-                return '';
+                throw new ContentProcessorException(
+                    new Phrase('Compilation from source: LESS file is empty: ' . $path)
+                );
             } else {
                 return $content;
             }

lib/internal/Magento/Framework/Css/Test/Unit/PreProcessor/Adapter/Less/ProcessorTest.php

@@ -111,6 +111,9 @@ public function testProcessContentException()
 
     /**
      * Test for processContent method (empty content)
+     *
+     * @expectedException \Magento\Framework\View\Asset\ContentProcessorException
+     * @expectedExceptionMessageRegExp (Compilation from source: LESS file is empty: test-path)
      */
     public function testProcessContentEmpty()
     {