planning

node_modules/graphql/validation/rules/LoneSchemaDefinitionRule.mjs

@@ -0,0 +1,28 @@
+import { GraphQLError } from "../../error/GraphQLError.mjs";
+
+/**
+ * Lone Schema definition
+ *
+ * A GraphQL document is only valid if it contains only one schema definition.
+ */
+export function LoneSchemaDefinitionRule(context) {
+  var _ref, _ref2, _oldSchema$astNode;
+
+  var oldSchema = context.getSchema();
+  var alreadyDefined = (_ref = (_ref2 = (_oldSchema$astNode = oldSchema === null || oldSchema === void 0 ? void 0 : oldSchema.astNode) !== null && _oldSchema$astNode !== void 0 ? _oldSchema$astNode : oldSchema === null || oldSchema === void 0 ? void 0 : oldSchema.getQueryType()) !== null && _ref2 !== void 0 ? _ref2 : oldSchema === null || oldSchema === void 0 ? void 0 : oldSchema.getMutationType()) !== null && _ref !== void 0 ? _ref : oldSchema === null || oldSchema === void 0 ? void 0 : oldSchema.getSubscriptionType();
+  var schemaDefinitionsCount = 0;
+  return {
+    SchemaDefinition: function SchemaDefinition(node) {
+      if (alreadyDefined) {
+        context.reportError(new GraphQLError('Cannot define a new schema within a schema extension.', node));
+        return;
+      }
+
+      if (schemaDefinitionsCount > 0) {
+        context.reportError(new GraphQLError('Must provide only one schema definition.', node));
+      }
+
+      ++schemaDefinitionsCount;
+    }
+  };
+}