Add check for required properties in error objects

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 - Dropped support for PHP 7.4 and PHP 8.0
 
+### Fixed
+
+- Add check that an error object contains at least one of `id`, `links`, `status`, `code`, `title`, `detail`, `source` or `meta`.
+
 ### Deprecated
 
 - `\Art4\Accessable::get()` will add `mixed` as a native return type declaration in 2.0.0, do the same in your implementation now to avoid errors.

src/V1/Error.php

@@ -33,6 +33,10 @@ protected function parse(mixed $object): void
             );
         }
 
+        if (!property_exists($object, 'id') and !property_exists($object, 'links') and !property_exists($object, 'status') and !property_exists($object, 'code') and !property_exists($object, 'title') and !property_exists($object, 'detail') and !property_exists($object, 'source') and !property_exists($object, 'meta')) {
+            throw new ValidationException('An error object MUST contain at least one of: `id`, `links`, `status`, `code`, `title`, `detail`, `source` or `meta`.');
+        }
+
         if (property_exists($object, 'id')) {
             if (!is_string($object->id)) {
                 throw new ValidationException(

tests/Unit/V1/ErrorTest.php

@@ -161,4 +161,28 @@ public function testCreateDetailWithoutStringThrowsException(mixed $input): void
 
         $error = new Error($object, $this->manager, $this->parent);
     }
+
+    /**
+     * An error object MAY have the following members, and MUST contain at least one of:
+     * - id
+     * - links
+     * - status
+     * - code
+     * - title
+     * - details
+     * - source
+     * - meta
+     */
+    public function testCreateWithoutRequiredPropertiesThrowsException(): void
+    {
+        $object = new \stdClass();
+        $object->description = 'error description';
+
+        $this->expectException(ValidationException::class);
+        $this->expectExceptionMessage(
+            'An error object MUST contain at least one of: `id`, `links`, `status`, `code`, `title`, `detail`, `source` or `meta`.'
+        );
+
+        $error = new Error($object, $this->manager, $this->parent);
+    }
 }