Ensure incomplete state is saved in case of patching application failure, improve error message during patching failure

Author: pinkeen

src/Exception/PatchApplicationFailedException.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Creativestyle\Composer\Patchset\Exception;
+
+use Throwable;
+
+class PatchApplicationFailedException extends PatchingException
+{
+    /**
+     * @var string
+     */
+    private $cmd;
+
+    /**
+     * @var string
+     */
+    private $cmdOutput;
+
+    public function __construct($cmd, $cmdOutput, $message = "", $code = 0, Throwable $previous = null)
+    {
+        if (empty($message)) {
+            $message = "Could not apply patch - command \"$cmd\" failed with: \n$cmdOutput";
+        }
+
+        parent::__construct($message, $code, $previous);
+
+        $this->cmd = $cmd;
+        $this->cmdOutput = $cmdOutput;
+    }
+
+    /**
+     * @return string
+     */
+    public function getCmd()
+    {
+        return $this->cmd;
+    }
+
+    /**
+     * @return string
+     */
+    public function getCmdOutput()
+    {
+        return $this->cmdOutput;
+    }
+}

src/Exception/PatchingException.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Creativestyle\Composer\Patchset\Exception;
+
+class PatchingException extends \RuntimeException
+{
+
+}

src/PatchApplicator.php

@@ -7,6 +7,7 @@
 use Composer\Util\Filesystem;
 use Composer\Util\ProcessExecutor;
 
+use Creativestyle\Composer\Patchset\Exception\PatchApplicationFailedException;
 use Psr\Log\LoggerInterface;
 
 class PatchApplicator
@@ -47,7 +48,12 @@ class PatchApplicator
     /**
      * @var string
      */
-    private $cmdErr;
+    private $lastCmd;
+
+    /**
+     * @var string
+     */
+    private $lastCmdOutput;
 
     /**
      * @var Filesystem
@@ -82,8 +88,16 @@ private function executeCommand($cmd, $cwd = null)
             $cmd = $cmd[0] . ' ' .implode(' ', array_map([ProcessExecutor::class, 'escape'], array_slice($cmd, 1)));
         }
 
-        $returnCode = $this->executor->execute($cmd, $output, $cwd);
-        $this->cmdErr = $this->executor->getErrorOutput();
+        $output = '';
+
+        $outputHandler = function($type, $buffer) use (&$output) {
+            $output .= $buffer;
+        };
+
+        $returnCode = $this->executor->execute($cmd, $outputHandler, $cwd);
+
+        $this->lastCmd = $cmd;
+        $this->lastCmdOutput = $output;
 
         return $returnCode;
     }
@@ -145,7 +159,7 @@ public function applyPatch(Patch $patch, PackageInterface $sourcePackage, Packag
         $patchFilename = $this->pathResolver->getPatchSourceFilePath($sourcePackage, $patch);
 
         if (!$this->executePatchCommand($patch->getMethod(), $targetDirectory, $patchFilename, $patch->getStripPathComponents())) {
-            throw new \RuntimeException('Could not apply patch: ' . $this->cmdErr);
+            throw new PatchApplicationFailedException($patchFilename, $this->lastCmdOutput);
         }
 
         $this->logger->notice(sprintf('Applied patch <info>%s:%s</info> [<comment>%s</comment>] (<comment>%s</comment>) using <comment>%s</comment> method',

src/Patcher.php

@@ -11,6 +11,7 @@
 use Composer\Repository\ArrayRepository;
 use Composer\Repository\RepositoryManager;
 use Composer\Util\ProcessExecutor;
+use Creativestyle\Composer\Patchset\Exception\PatchApplicationFailedException;
 use Psr\Log\LoggerInterface;
 
 class Patcher
@@ -290,15 +291,39 @@ private function applyPatches()
                 $packagePatchApplication->getTargetPackage()->getPrettyVersion()
             ));
 
+            /** @var PatchApplicationFailedException|null $applicationFailedException */
+            $applicationFailedException = null;
+            
+            /** @var PatchApplication[] $processedPatchApplications */
+            $processedPatchApplications = [];
+
             foreach ($packagePatchApplication->getApplications() as $patchApplication) {
-                $this->applicator->applyPatch(
-                    $patchApplication->getPatch(),
-                    $patchApplication->getSourcePackage(),
-                    $patchApplication->getTargetPackage()
-                );
+                try {
+                    $this->applicator->applyPatch(
+                        $patchApplication->getPatch(),
+                        $patchApplication->getSourcePackage(),
+                        $patchApplication->getTargetPackage()
+                    );
+                } catch (PatchApplicationFailedException $exception) {
+                    // Break out of the loop to save current state (already applied patches).
+                    $applicationFailedException = $exception;
+                    break;
+                }
+
+                $processedPatchApplications[] = $patchApplication;
             }
 
-            $this->packageApplicationRepository->savePackageApplication($packagePatchApplication);
+            $this->packageApplicationRepository->savePackageApplication(
+                new PackagePatchApplication(
+                    $packagePatchApplication->getTargetPackage(),
+                    $processedPatchApplications
+                )
+            );
+
+            if ($applicationFailedException) {
+                // We still rethrow the exception after handling it gracefully
+                throw $applicationFailedException;
+            }
         }
     }