Expose Application Failure ErrorCategory

src/Exception/Failure/ApplicationErrorCategory.php

@@ -0,0 +1,27 @@
+<?php
+
+/**
+ * This file is part of Temporal package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace Temporal\Exception\Failure;
+
+/**
+ * Used to categorize application failures, for example, to distinguish benign errors from others.
+ *
+ * @see \Temporal\Api\Enums\V1\ApplicationErrorCategory
+ */
+enum ApplicationErrorCategory: int
+{
+    case Unspecified = 0;
+
+    /**
+     * Expected application error with little/no severity.
+     */
+    case Benign = 1;
+}

src/Exception/Failure/ApplicationFailure.php

@@ -49,6 +49,7 @@ class ApplicationFailure extends TemporalFailure
     /**
      * @param ValuesInterface|null $details Optional details about the failure.
      * @param \DateInterval|null $nextRetryDelay Delay before the next retry attempt.
+     * @param ApplicationErrorCategory $category The category of the application failure.
      */
     public function __construct(
         string $message,
@@ -57,6 +58,7 @@ public function __construct(
         ?ValuesInterface $details = null,
         ?\Throwable $previous = null,
         private ?\DateInterval $nextRetryDelay = null,
+        private readonly ApplicationErrorCategory $category = ApplicationErrorCategory::Unspecified,
     ) {
         parent::__construct(
             self::buildMessage(\compact('message', 'type', 'nonRetryable')),
@@ -103,4 +105,9 @@ public function setNextRetryDelay(?\DateInterval $nextRetryDelay): void
     {
         $this->nextRetryDelay = $nextRetryDelay;
     }
+
+    public function getApplicationErrorCategory(): ApplicationErrorCategory
+    {
+        return $this->category;
+    }
 }

src/Exception/Failure/FailureConverter.php

@@ -70,6 +70,7 @@ public static function mapExceptionToFailure(\Throwable $e, DataConverterInterfa
                 $info = new ApplicationFailureInfo();
                 $info->setType($e->getType());
                 $info->setNonRetryable($e->isNonRetryable());
+                $info->setCategory($e->getApplicationErrorCategory()->value);
 
                 // Set Next Retry Delay
                 $nextRetry = DateInterval::toDuration($e->getNextRetryDelay());
@@ -181,6 +182,7 @@ private static function createFailureException(Failure $failure, DataConverterIn
                     $details,
                     $previous,
                     DateInterval::parseOrNull($info->getNextRetryDelay()),
+                    ApplicationErrorCategory::tryFrom($info->getCategory()) ?? ApplicationErrorCategory::Unspecified,
                 );
 
             case $failure->hasTimeoutFailureInfo():

tests/Unit/Exception/FailureConverterTestCase.php

@@ -10,6 +10,7 @@
 use Temporal\Api\Failure\V1\Failure;
 use Temporal\DataConverter\DataConverter;
 use Temporal\DataConverter\EncodedValues;
+use Temporal\Exception\Failure\ApplicationErrorCategory;
 use Temporal\Exception\Failure\ApplicationFailure;
 use Temporal\Exception\Failure\FailureConverter;
 use Temporal\Tests\Unit\AbstractUnit;
@@ -178,5 +179,23 @@ public function testMapExceptionToFailure(): void
         $this->assertTrue($failure->getApplicationFailureInfo()->getNonRetryable());
         $this->assertEmpty($failure->getApplicationFailureInfo()->getDetails());
         $this->assertNull($failure->getApplicationFailureInfo()->getNextRetryDelay());
+        $this->assertSame(0, $failure->getApplicationFailureInfo()->getCategory());
+    }
+
+    public function testMapAppFailureWithCategory(): void
+    {
+        $converter = DataConverter::createDefault();
+        $exception = new ApplicationFailure(
+            'message',
+            'type',
+            true,
+            category: ApplicationErrorCategory::Benign,
+        );
+
+        $failure = FailureConverter::mapExceptionToFailure($exception, $converter);
+        $newException = FailureConverter::mapFailureToException($failure, $converter);
+
+        self::assertInstanceOf(ApplicationFailure::class, $newException);
+        $this->assertSame(ApplicationErrorCategory::Benign, $newException->getApplicationErrorCategory());
     }
 }