Version 4.6.0

system/3rd_party/graphql-php/Validator/Rules/LoneSchemaDefinition.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace GraphQL\Validator\Rules;
+
+use GraphQL\Error\Error;
+use GraphQL\Language\AST\NodeKind;
+use GraphQL\Language\AST\SchemaDefinitionNode;
+use GraphQL\Validator\SDLValidationContext;
+
+/**
+ * Lone Schema definition
+ *
+ * A GraphQL document is only valid if it contains only one schema definition.
+ */
+class LoneSchemaDefinition extends ValidationRule
+{
+    public static function schemaDefinitionNotAloneMessage()
+    {
+        return 'Must provide only one schema definition.';
+    }
+
+    public static function canNotDefineSchemaWithinExtensionMessage()
+    {
+        return 'Cannot define a new schema within a schema extension.';
+    }
+
+    public function getSDLVisitor(SDLValidationContext $context)
+    {
+        $oldSchema      = $context->getSchema();
+        $alreadyDefined = $oldSchema !== null
+            ? (
+                $oldSchema->getAstNode() !== null ||
+                $oldSchema->getQueryType() !== null ||
+                $oldSchema->getMutationType() !== null ||
+                $oldSchema->getSubscriptionType() !== null
+            )
+            : false;
+
+        $schemaDefinitionsCount = 0;
+
+        return [
+            NodeKind::SCHEMA_DEFINITION => static function (SchemaDefinitionNode $node) use ($alreadyDefined, $context, &$schemaDefinitionsCount) : void {
+                if ($alreadyDefined !== false) {
+                    $context->reportError(new Error(self::canNotDefineSchemaWithinExtensionMessage(), $node));
+
+                    return;
+                }
+
+                if ($schemaDefinitionsCount > 0) {
+                    $context->reportError(new Error(self::schemaDefinitionNotAloneMessage(), $node));
+                }
+
+                ++$schemaDefinitionsCount;
+            },
+        ];
+    }
+}