Initialisation

Added the packages and files for the backend server

node_modules/graphql/validation/rules/custom/NoSchemaIntrospectionCustomRule.mjs

@@ -0,0 +1,32 @@
+import { GraphQLError } from '../../../error/GraphQLError.mjs';
+import { getNamedType } from '../../../type/definition.mjs';
+import { isIntrospectionType } from '../../../type/introspection.mjs';
+
+/**
+ * Prohibit introspection queries
+ *
+ * A GraphQL document is only valid if all fields selected are not fields that
+ * return an introspection type.
+ *
+ * Note: This rule is optional and is not part of the Validation section of the
+ * GraphQL Specification. This rule effectively disables introspection, which
+ * does not reflect best practices and should only be done if absolutely necessary.
+ */
+export function NoSchemaIntrospectionCustomRule(context) {
+  return {
+    Field(node) {
+      const type = getNamedType(context.getType());
+
+      if (type && isIntrospectionType(type)) {
+        context.reportError(
+          new GraphQLError(
+            `GraphQL introspection has been disabled, but the requested query contained the field "${node.name.value}".`,
+            {
+              nodes: node,
+            },
+          ),
+        );
+      }
+    },
+  };
+}