| /** @category Validation Rules */ |
| import { GraphQLError } from '../../error/GraphQLError.mjs'; |
| |
| /** |
| * Unique type names |
| * |
| * A GraphQL document is only valid if all defined types have unique names. |
| * @param context - The validation context used while checking the document. |
| * @returns A visitor that reports validation errors for this rule. |
| * @example |
| * ```ts |
| * import { buildSchema } from 'graphql'; |
| * import { UniqueTypeNamesRule } from 'graphql/validation'; |
| * |
| * const invalidSDL = ` |
| * type Query { name: String } type Query { other: String } |
| * `; |
| * |
| * UniqueTypeNamesRule.name; // => 'UniqueTypeNamesRule' |
| * buildSchema(invalidSDL); // throws an error |
| * |
| * const validSDL = ` |
| * type Query { name: String } type Other { name: String } |
| * `; |
| * |
| * buildSchema(validSDL); // does not throw |
| * ``` |
| */ |
| export function UniqueTypeNamesRule(context) { |
| const knownTypeNames = Object.create(null); |
| const schema = context.getSchema(); |
| return { |
| ScalarTypeDefinition: checkTypeName, |
| ObjectTypeDefinition: checkTypeName, |
| InterfaceTypeDefinition: checkTypeName, |
| UnionTypeDefinition: checkTypeName, |
| EnumTypeDefinition: checkTypeName, |
| InputObjectTypeDefinition: checkTypeName, |
| }; |
| |
| function checkTypeName(node) { |
| const typeName = node.name.value; |
| |
| if (schema !== null && schema !== void 0 && schema.getType(typeName)) { |
| context.reportError( |
| new GraphQLError( |
| `Type "${typeName}" already exists in the schema. It cannot also be defined in this type definition.`, |
| { |
| nodes: node.name, |
| }, |
| ), |
| ); |
| return; |
| } |
| |
| if (knownTypeNames[typeName]) { |
| context.reportError( |
| new GraphQLError(`There can be only one type named "${typeName}".`, { |
| nodes: [knownTypeNames[typeName], node.name], |
| }), |
| ); |
| } else { |
| knownTypeNames[typeName] = node.name; |
| } |
| |
| return false; |
| } |
| } |