Allow multiple error formatters

conf/config.neon

@@ -2174,3 +2174,9 @@ services:
 		class: PHPStan\Command\ErrorFormatter\TeamcityErrorFormatter
 		arguments:
 			relativePathHelper: @simpleRelativePathHelper
+
+	errorFormatter.multiple:
+		class: PHPStan\Command\ErrorFormatter\ChainErrorFormatter
+		arguments:
+			formatters:
+				- @errorFormatter.table

src/Command/ErrorFormatter/ChainErrorFormatter.php

@@ -0,0 +1,32 @@
+<?php declare(strict_types=1);
+
+namespace PHPStan\Command\ErrorFormatter;
+
+use PHPStan\Command\AnalysisResult;
+use PHPStan\Command\Output;
+
+/**
+ * @api
+ */
+final class ChainErrorFormatter implements ErrorFormatter
+{
+
+	/**
+	 * @param list<ErrorFormatter> $formatters
+	 */
+	public function __construct(
+		private array $formatters,
+	)
+	{
+	}
+
+	public function formatErrors(AnalysisResult $analysisResult, Output $output): int
+	{
+		foreach ($this->formatters as $errorFormatter) {
+			$errorFormatter->formatErrors($analysisResult, $output);
+		}
+
+		return $analysisResult->hasErrors() ? 1 : 0;
+	}
+
+}

src/Command/ErrorFormatter/GitlabErrorFormatter.php

@@ -6,6 +6,7 @@
 use PHPStan\Command\AnalysisResult;
 use PHPStan\Command\Output;
 use PHPStan\File\RelativePathHelper;
+use function file_put_contents;
 use function hash;
 use function implode;
 
@@ -15,7 +16,10 @@
 final class GitlabErrorFormatter implements ErrorFormatter
 {
 
-	public function __construct(private RelativePathHelper $relativePathHelper)
+	public function __construct(
+		private RelativePathHelper $relativePathHelper,
+		private ?string $fileLocation = null,
+	)
 	{
 	}
 
@@ -64,7 +68,11 @@ public function formatErrors(AnalysisResult $analysisResult, Output $output): in
 
 		$json = Json::encode($errorsArray, Json::PRETTY);
 
-		$output->writeRaw($json);
+		if ($this->fileLocation !== null) {
+			file_put_contents($this->fileLocation, $json);
+		} else {
+			$output->writeRaw($json);
+		}
 
 		return $analysisResult->hasErrors() ? 1 : 0;
 	}