Created middleware to keep backwards compatibility on errors when using v1 and 2 of the API

module/Rest/src/Exception/BackwardsCompatibleProblemDetailsException.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Rest\Exception;
+
+use Mezzio\ProblemDetails\Exception\ProblemDetailsExceptionInterface;
+use Shlinkio\Shlink\Core\Exception\ValidationException;
+
+/** @deprecated */
+class BackwardsCompatibleProblemDetailsException extends RuntimeException implements ProblemDetailsExceptionInterface
+{
+    private function __construct(private readonly ProblemDetailsExceptionInterface $e)
+    {
+        parent::__construct($e->getMessage(), $e->getCode(), $e);
+    }
+
+    public static function fromProblemDetails(ProblemDetailsExceptionInterface $e): self
+    {
+        return new self($e);
+    }
+
+    public function getStatus(): int
+    {
+        return $this->e->getStatus();
+    }
+
+    public function getType(): string
+    {
+        return $this->remapType($this->e->getType());
+    }
+
+    public function getTitle(): string
+    {
+        return $this->e->getTitle();
+    }
+
+    public function getDetail(): string
+    {
+        return $this->e->getDetail();
+    }
+
+    public function getAdditionalData(): array
+    {
+        return $this->e->getAdditionalData();
+    }
+
+    public function toArray(): array
+    {
+        return $this->remapTypeInArray($this->e->toArray());
+    }
+
+    public function jsonSerialize(): array
+    {
+        return $this->remapTypeInArray($this->e->jsonSerialize());
+    }
+
+    private function remapTypeInArray(array $wrappedArray): array
+    {
+        if (! isset($wrappedArray['type'])) {
+            return $wrappedArray;
+        }
+
+        return [...$wrappedArray, 'type' => $this->remapType($wrappedArray['type'])];
+    }
+
+    private function remapType(string $wrappedType): string
+    {
+        return match ($wrappedType) {
+            ValidationException::TYPE => 'INVALID_ARGUMENT',
+            default => $wrappedType,
+        };
+    }
+}

module/Rest/src/Middleware/ErrorHandler/BackwardsCompatibleProblemDetailsHandler.php

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+<?php
+
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Rest\Middleware\ErrorHandler;
+
+use Mezzio\ProblemDetails\Exception\ProblemDetailsExceptionInterface;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+use Shlinkio\Shlink\Rest\Exception\BackwardsCompatibleProblemDetailsException;
+
+use function version_compare;
+
+/** @deprecated */
+class BackwardsCompatibleProblemDetailsHandler implements MiddlewareInterface
+{
+    public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
+    {
+        try {
+            return $handler->handle($request);
+        } catch (ProblemDetailsExceptionInterface $e) {
+            $version = $request->getAttribute('version') ?? '2';
+            throw version_compare($version, '3', '>=')
+                ? $e
+                : BackwardsCompatibleProblemDetailsException::fromProblemDetails($e);
+        }
+    }
+}