Add formatter that is optimized for DD ingress

Author: sunkan

src/Formatter/DataDogFormatter.php

@@ -0,0 +1,75 @@
+<?php declare(strict_types=1);
+
+namespace Stefna\Logger\Formatter;
+
+use Monolog\Formatter\JsonFormatter;
+use Monolog\LogRecord;
+
+final class DataDogFormatter extends JsonFormatter
+{
+	protected function normalizeRecord(LogRecord $record): array
+	{
+		/**
+		 * @var array{
+		 *     context: array{
+		 *         "error.kind"?: string,
+		 *         "error.message": string,
+		 *         "error.stack": string,
+		 *         exception?: mixed,
+		 *     },
+		 *     ddsource?: string,
+		 *     ddtags?: string,
+		 *     logger?: mixed
+		 * } $data
+		 */
+		$data = parent::normalizeRecord($record);
+		/**
+		 * @var array{
+		 *     exception?: mixed,
+		 *     "error.kind"?: string,
+		 *     ddtags?: string,
+		 *     traceId?: string,
+		 * } $context
+		 */
+		$context = $record->context;
+
+		if (isset($data['context']['error.kind'])) {
+			$data['error'] = [
+				'message' => $data['context']['error.message'],
+				'stack' => $data['context']['error.stack'],
+				'kind' => $data['context']['error.kind'],
+			];
+			unset($data['context']['error.kind'], $data['context']['error.message'], $data['context']['error.stack']);
+		}
+		elseif (isset($context['exception']) && $context['exception'] instanceof \Throwable) {
+			$data['error'] = [
+				'message' => $context['exception']->getMessage(),
+				'stack' => $context['exception']->getTraceAsString(),
+				'kind' => $context['exception']::class,
+			];
+			unset($data['context']['exception']);
+		}
+
+		$data['source'] = 'php';
+		if (!isset($data['ddsource'])) {
+			$data['ddsource'] = $data['source'];
+		}
+		if (!isset($data['ddtags']) && isset($context['ddtags'])) {
+			$data['ddtags'] = $context['ddtags'];
+		}
+		if (isset($context['traceId'])) {
+			$data['dd']['trace_id'] = $context['traceId'];
+		}
+		if (isset($record->extra['version'])) {
+			$data['dd']['version'] = $record->extra['version'];
+		}
+		if (!isset($data['logger'])) {
+			$data['logger'] = [
+				'channel' => $record->channel,
+				'message' => $record->message,
+			];
+		}
+
+		return $data;
+	}
+}